UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

PROXY STATEMENT PURSUANT TO SECTION 14(A)

OF THE SECURITIES EXCHANGE ACT OF 1934

Filed by the Registrant  ☒

Filed by a Party other than the Registrant  ☐

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ALTAIR ENGINEERING INC.

(Name of Registrant as Specified In Its Charter)

(Name(s) of Person(s) Filing Proxy Statement, if Other Than the Registrant)

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ALTAIR ENGINEERING INC.

1820 East Big Beaver Road

Troy, Michigan 48083

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

To be held on May 19, 202020, 2021

To the Stockholders of

Altair Engineering Inc.

You are cordially invited to attend the Annual Meeting of Stockholders (the “Annual Meeting”) of Altair Engineering Inc. (the “Company”) to be held on Tuesday,Thursday, May 19, 202020, 2021 at 9:1:00 a.m.p.m. Eastern Time. In light of thecoronavirus/COVID-19 outbreak coronavirus and governmental decrees thatin-person gatherings be postponed or canceled,limited, and in the best interests of public health and the health and safety of our stockholders, employees and Board of Directors, we are planning to hold the Annual Meeting virtually via the Internet at www.virtualshareholdermeeting.com/ALTR2020. Unless we publicly announce a change in our plans in the manner described in the attached proxy statement, youALTR2021. You will not be able to attend the Annual Meeting at a physical location. At the Annual Meeting, stockholders will act on the following matters:

Only stockholders of record at the close of business on March 24, 202025, 2021 are entitled to receive notice of and to vote at the Annual Meeting or any postponement or adjournment thereof.

Your vote is important. Whether or not you plan to attend the meeting, please vote electronically via the Internet or by telephone, or, if you requested paper copies of the proxy materials, please complete, sign, date and return the accompanying proxy card or voting instruction card in the enclosed postage-paid envelope. If you attend the meeting and prefer to vote in person, you may do so even if you have already voted your shares. You may revoke your proxy in the manner described in the proxy statement at any time before it has been voted at the meeting.

By Order of the Board of Directors

/s/ James R. Scapa

James R. Scapa

Chairman and Chief Executive Officer

April 9, 20202021

Troy, Michigan

TABLE OF CONTENTS

ALTAIR ENGINEERING INC.

PROXY STATEMENT

FOR THE 20202021 ANNUAL MEETING OF STOCKHOLDERS

GENERAL INFORMATION

This proxy statement contains information related to the Annual Meeting of Stockholders to be held on Tuesday,Thursday, May 19, 202021, 2021 at 9:1:00 a.m.p.m. Eastern Time. In light of thecoronavirus/COVID-19 outbreak coronavirus and governmental decrees thatin-person gatherings be postponed or canceled,limited, and in the best interests of public health and the health and safety of our stockholders, employees and Board of Directors, we are planning to hold the Annual Meeting virtually via the Internet. Unless we publicly announce a change in our plans, inInternet, or at such other time and place to which the Annual Meeting may be adjourned or postponed. In order to attend our Annual Meeting, you must log in to www.virtualshareholdermeeting.com/ALTR2020ALTR2021 using the16-digit control number on the Notice, proxy card or voting instruction form that accompanied the proxy materials.

Our Annual Meeting could be adjourned or postponed to another date and/or time. If the pandemic abates to the extent that the Company believes that it will be safe for all constituencies to attend a meeting at a physical location, we may also determine to revert to our original plans to hold the Annual Meeting at a physical location. If we make any such determination, we will announce plans to hold a meeting at a physical location in a press release that we will disseminate and file with the SEC and on the investor relations page of our website at http://investor.altair.com. In such event, our meeting would be held at our offices, 1820 East Big Beaver Road, Troy, Michigan 48083. At this point, however, we expect to hold the Annual Meeting virtually via the Internet.

Proxies for the Annual Meeting are being solicited by Altair’s Board of Directors (the “Board”). This proxy statement is first being made available to stockholders on or about April 9, 2020.2021.

Important Notice of Availability of Proxy Materials for the Annual Meeting of Stockholders to be held on May 19, 2020.21, 2021.

Our proxy materials including our Notice of Internet Availability of Proxy Materials, Proxy Statement for the 20202021 Annual Meeting, our annual report for the fiscal year ended December 31, 20192020 and proxy card are available on the Internet at www.proxyvote.com. Under Securities and Exchange Commission rules, we are providing access to our proxy materials by notifying you of the availability of our proxy materials on the Internet.

In this Proxy Statement, the terms “Altair,” “we,” “us,” and “our” refer to Altair Engineering Inc. The mailing address of our principal executive offices is Altair Engineering Inc., 1820 East Big Beaver Road, Troy, Michigan 48083.

About the Meeting

Why are we calling this Annual Meeting?

We are calling the Annual Meeting to seek the approval of our stockholders:

best interests of Altair and its stockholders and recommends that you vote FOR these proposals. Our Board believes that the compensation of our named executive officers for the year ended December 31, 2019,2020, as described in this proxy statement, was appropriate and recommends that you voteFOR the resolution to approve that compensation. If you are a stockholder of record and you return a properly executed proxy card or vote by proxy over the Internet but do not mark the boxes showing how you wish to vote, your shares will be voted in accordance with the recommendations of the Board, as set forth above. With respect to any other matter that properly comes before our Annual Meeting, the proxy holders will vote as recommended by the Board or, if no recommendation is given, at their own discretion.

Who is entitled to vote at the meeting?

Only holders of record of our Class A common stock and Class B common stock at the close of business on the record date, March 24, 2020,25, 2021, are entitled to receive notice of the Annual Meeting and to vote either class of our common stock that they held on that date at the meeting, or any postponement or adjournment of the meeting. Each share of Class A common stock is entitled to one vote on each proposal and each share of Class B common stock is entitled to ten votes on each proposal.

As of the record date, there were 41,776,09245,422,380 shares of our Class A common stock outstanding and 31,050,73229,600,192 shares of our Class B common stock outstanding. Our Class A common stock and Class B common stock will vote as a single class on all matters described in this proxy statement. Our Class A common stock and Class B common stock are collectively referred to in this proxy statement as our common stock.

Who can attend the meeting?

All stockholders as of the record date, or their duly appointed proxies, may attend the Annual Meeting. If, as we expect,Attendance at the Annual Meeting is held virtually, attendance shall solely be via the Internet at www.virtualshareholdermeeting.com/ALTR2020ALTR2021 using the16-digit control number on the Notice, proxy card or voting instruction form that accompanied the proxy materials. In that event, stockholdersStockholders will not be able to attend the Annual Meeting at a physical location.

The live webcast of the Annual Meeting will begin promptly at 9:1:00 ampm Eastern Time. Online access to the audio webcast will open approximately 30 minutes prior to the start of the Annual Meeting to allow time for our stockholders to log in and test their devices’ audio system. We encourage our stockholders to access the meeting in advance of the designated start time.

An online portal will be available to our stockholders at www.proxyvote.com commencing approximately on or about April 9, 2020.2021. By accessing this portal, stockholders will be able to vote in advance of the Annual Meeting. Stockholders may also vote, and submit questions, during the Annual Meeting on www.virtualshareholdermeeting.com/ALTR2020.ALTR2021. To demonstrate proof of stock ownership, you will need to enter the16-digit control number received with your Notice, proxy card or voting instruction form to submit questions and vote at our Annual Meeting. If you hold your shares in “street name” (that is, through a broker or other nominee), you will need authorization from your broker or nominee in order to vote. We intend to answer questions submitted during the meeting that are pertinent to the Company and the items being brought for stockholder vote at the Annual Meeting, as time permits, and in accordance with the Rules of Conduct for the Annual Meeting. To promote fairness, efficiently use the Company’s resources and ensure all stockholder questions are able to be addressed, we will respond to no more than three questions from a single stockholder. We have retained Broadridge Financial Solutions to host our virtual annual meeting and to distribute, receive, count and tabulate proxies.

In the event that we announce that we have changed our plans and intend to hold the meeting in person at our offices, in order to attend in person at our offices:

What constitutes a quorum?

The presence at the Annual Meeting, in person or by proxy, of a majority of the voting power of all issued and outstanding shares of our common stock entitled to vote at the Annual Meeting will constitute a quorum for our meeting. Signed proxies received but not voted and brokernon-votes will be included in the calculation of the number of shares considered to be present at the meeting.

How do I vote?

Your vote is important. Instead of mailing a printed copy of our proxy materials to all of our stockholders, we provide access to these materials via the Internet. This reduces the amount of paper necessary to produce these materials as well as the costs associated with mailing these materials to all stockholders. Accordingly, on or about April 9, 2020,2021, we will begin mailing a Notice of Internet Availability of Proxy Materials (the “Notice”) to all stockholders of record on our books at the close of business on the record date and will post our proxy materials at www.proxyvote.com. Stockholders may choose to access our proxy materials at www.proxyvote.com or may request to receive a printed set of our proxy materials. In addition, the Notice and that website provide information regarding how you may request to receive proxy materials in printed form by mail, or electronically by email, on an ongoing basis.

You may vote on the Internet, by telephone, by mail or by attending the Annual Meeting and voting electronically, (or by ballot if the meeting is held at our offices), all as described below. The Internet and telephone voting procedures are designed to authenticate stockholders by use of a control number and to allow you to confirm that your instructions have been properly recorded. If you vote by telephone or on the Internet, you do not need to return your proxy card or voting instruction card.

Vote on the Internet

If you are a stockholder of record, you may submit your proxy by going to www.proxyvote.com and following the instructions provided in the Notice. If you requested printed proxy materials, you may follow the instructions provided with your proxy materials and on your proxy card. If your shares are held with a broker, you will need to go to the website provided on your Notice or voting instruction card. Have your Notice, proxy card or voting instruction card in hand when you access the voting website. On the Internet voting site, you can confirm that your instructions have been properly recorded. If you vote on the Internet, you can also request electronic delivery of future proxy materials.Internet voting facilities are available now and will be available 24 hours a day until 11:59 p.m., Eastern Time, on May 18, 2020.19, 2021.

Vote by Telephone

If you are a stockholder of record, you can also vote by telephone by dialing1-800-690-6903. If your shares are held with a broker, you can vote by telephone by dialing the number specified on your voting instruction

Please note that if you received a Notice of Internet Availability, youcannot vote by marking the Notice and returning it. The Notice provides instructions on how to vote on the Internet and how to request paper copies of the proxy materials.

Voting at the Annual Meeting

You will have the right to vote at the Annual Meeting.

If, as we expect, we hold the Annual Meeting remotely via the Internet, youYou will have the right to vote on the day of, or during, the Annual Meeting on www.virtualshareholdermeeting.com/ALTR2020.ALTR2021. To demonstrate proof of stock ownership, you will need to enter the16-digit control number received with your Notice, proxy card or voting instruction form to vote at our Annual Meeting if it is held remotely.

If we change our plans, hold the meeting at our offices and you attend the Annual Meeting, you may vote in person. However, if your shares are held in the name of a bank, broker or other nominee, you must obtain a legal proxy, executed in your favor, from the holder of record to be able to vote in person at the Annual Meeting. In that case, you should allow yourself enough time prior to the Annual Meeting to obtain this proxy from the holder of record.

Even if you plan to attend our Annual Meeting remotely, we recommend that you also submit your proxy as described above so that your vote will be counted if you later decide not to attend our Annual Meeting.

The shares voted electronically, telephonically, or represented by the proxy cards received, properly marked, dated, signed and not revoked, will be voted at the Annual Meeting.

What if I vote and then change my mind?

You may revoke your proxy at any time before it is exercised by:

Your latest vote will be the vote that is counted.

What is the difference between holding shares as a stockholder of record and as a beneficial owner?

Many of our stockholders hold their shares through a stockbroker, bank or other nominee rather than directly in their own name. As summarized below, there are some distinctions between shares held of record and those owned beneficially.

What vote is required to approve each proposal?

The holders of a majority of the voting power of the common stock issued and outstanding on the record date must be present, in person or by proxy, at the Annual Meeting in order to have the required quorum for the transaction of business. Pursuant to Delaware corporate law, abstentions and brokernon-votes will be counted for the purpose of determining whether a quorum is present.

With respect to the first proposal (election of a Class III directors)I director), directors arethe director will be elected by a plurality of the voting power of the shares of our common stock present or represented by proxy and entitled to vote, and the director nomineesnominee who receivereceives the greatest number of votes at the Annual Meeting (up to the total number of directors to be elected) will be elected. As a result, abstentions and “brokernon-votes” (see below), if any, will not affect the outcome of the vote on the first proposal.

With respect to the second, third and thirdfourth proposals, to approve the Altair Engineering Inc. 2021 Employee Stock Purchase Plan, to cast an advisory vote on executive compensation and to ratify the appointment of Ernst & Young LLP, respectively, and the approval of any other matter that may properly come before the Annual Meeting, the affirmative vote of a majority of the voting power of the shares of our common stock present or represented by proxy and entitled to vote, is required to approve these proposals. As a result, abstentions will have the same practical effect as a negative vote on these proposals, and “brokernon-votes” (see below), if any, will not affect the outcome of the vote on these proposals.

Holders of the common stock will not have any dissenters’ rights of appraisal in connection with any of the matters to be voted on at the meeting.

What are “brokernon-votes”?

Banks and brokers acting as nominees are permitted to use discretionary voting authority to vote proxies for proposals that are deemed “routine” by the New York Stock Exchange, but are not permitted to use discretionary voting authority to vote proxies for proposals that are deemed“non-routine” by the New York Stock Exchange. The determination of which proposals are deemed “routine” versus“non-routine” may not be made by the New York Stock Exchange until after the date on which this proxy statement has been mailed to you. As such, it is important that you provide voting instructions to your bank, broker or other nominee, if you wish to determine the voting of your shares. If the New York Stock Exchange determines a proposal to be“non-routine,” failure to vote, or to instruct your broker how to vote any shares held for you in your broker’s names, will have the same effect as a vote against such proposal.

We will also, upon request, reimburse brokers and other persons holding stock in their names, or in the names of nominees, for their reasonableout-of-pocket expenses for forwarding proxy materials to the beneficial owners of the capital stock and to obtain proxies.

PROPOSAL 1: TO ELECT TWO DIRECTORS,ONE DIRECTOR, AS A CLASS III DIRECTORS,I DIRECTOR, TO SERVE A THREE-YEAR TERMSTERM EXPIRING AT THE ANNUAL MEETING IN 20232024 AND UNTIL THEIR SUCCESSORS HAVEHER SUCCESSOR HAS BEEN DULY ELECTED AND QUALIFIED

Our Board is divided into three classes: Class I, Class II and Class III, with each class serving a three-year term. Vacancies on the Board may be filled only by persons elected by a majority of the remaining directors. A director elected by the Board to fill a vacancy in a class, including vacancies created by an increase in the number of directors, shall serve for the remainder of the full term of that class and until the director’s successor is duly elected and qualified.

TheOur Board presently has seven members. There are twothree directors in the class (Class I) whose term of office expires in 2020. Both2021 – Dr. Mary Boyce, Brett Chouinard and Jan Kowal. Messrs. Chouinard and Kowal are not standing for reelection at the Annual Meeting. As a result, the size of these directors havethe Board will be reduced to five members immediately prior to the Annual Meeting. Dr. Mary Boyce has been nominated for electionreelection as a Class III directorsI director at thisthe Annual Meeting. Each of the nominees listed below

Dr. Boyce is currently a director of Altair. If elected at the Annual Meeting, the Class III nomineesDr. Boyce would serve until the 20232024 annual meeting and until his or her successor has been duly elected and qualified, or, if sooner, until the director’sher death, resignation or removal.

Directors are elected by a plurality of the votes of the holders of shares present in person or represented by proxy and entitled to vote on the election of directors. Stockholders may not vote, or submit a proxy, for a greater number of nominees than the two nomineesone nominee named below. The two director nomineesnominee receiving the highest number of affirmative votes will be elected. SharesUnless otherwise directed, shares represented by executed proxies will be voted if authority to do so is not withheld, for the election of the two director nomineesnominee named below. If anythe director nominee becomes unavailable for election as a result of an unexpected occurrence, shares that would have been voted for that nominee will instead will be voted for the election of a substitute nominee proposed by our Board. Each person nominated for electionDr. Boyce has agreed to serve if elected. Our management has no reason to believe that any nomineeDr. Boyce will be unable to serve.

Class III NomineesI Nominee for Election for a Term Expiring at the 20232024 Annual Meeting

The following table sets forth the name, age, position and tenure of our Class III directorsI director who areis up forre-election at the 20202021 Annual Meeting for a term expiring at the 2023 Annual2024Annual Meeting:

The following biographical descriptions set forth certain information with respect to Dr. Boyce, based on information furnished to Altair by such director nominee.

Dr. Mary Boyce has served as a member of our board of directors since April 2018. Dr. Boyce is the director nominees,chair of our technology committee, a role she has held since October 2018, and a member of our nominating and corporate governance committee, a role she has held since August 2018. Dr. Boyce is Dean of The Fu Foundation School of Engineering and Applied Science at Columbia University in the City of New York, where she is also the Morris A. and Alma Schapiro Professor of Engineering. Prior to joining Columbia University in 2013, Dr. Boyce served on the faculty of the Massachusetts Institute of Technology (“MIT”) for over 25 years, leading the Mechanical Engineering Department from 2008 to 2013. She holds a BS degree in engineering science and mechanics from Virginia Tech, and MS and Ph.D. degrees in mechanical engineering from MIT. Dr. Boyce’s research focuses on materials and mechanics, particularly in the areas of multi-scale and nonlinear mechanics of polymers and soft composites, and her work has been documented in over 170 archival journal articles spanning materials, mechanics, and physics. She has mentored over 40 M.S. thesis students and over 25

Ph.D. students and has been widely recognized for her scholarly contributions, including election as a fellow of the American Society of Mechanical Engineers, the American Academy of Arts and Sciences, and the National Academy of Engineering. We believe Dr. Boyce is qualified to serve on our board of directors because of her extensive leadership experience and because she is a distinguished engineer and academic leader in the field of engineering.

THE BOARD OF DIRECTORS RECOMMENDS THAT THE STOCKHOLDERS VOTE FOR THE ELECTION OF THE CLASS I DIRECTOR NOMINEE.

Continuing Directors

The following table sets forth the name, age, position and tenure of the directors who are serving for terms that end following the Annual Meeting.

The following biographical descriptions set forth certain information with respect to directors who are serving for terms that end following the Annual Meeting, based on information furnished to Altair by each director.

Class II Directors Continuing in Office until the 2022 Annual Meeting

Trace Harris has served as a member of our Board since August 2016. Ms. Harris is the chair of our compensation committee, a role she has held since January 2017, and a member of our audit committee, a role she has held since August 2018. She also served as a member of our nominating and corporate governance committee from April 2017 through August 2018. Ms. Harris currently is a principal at T Harris LLC, which provides strategy and financial consulting, a position she has held since November 2014. Prior to that, she worked at A-List Services, LLC, an educational services provider, from January 2017 through January 2019, most recently as interim chief executive officer and chief financial officer. Prior to that, Ms. Harris spent 13 years, between September 2001 and November 2014, working in various roles at Vivendi SA, most recently serving as senior vice president, strategy, finance and business innovation. Since March 2021, Ms. Harris has served as a director nominee.of Anzu Special Purpose Acquisition Corp. I, a public special purpose acquisition company (Nasdaq: ANZUU). Ms. Harris holds a bachelor’s degree in economics from Stanford University and a master’s degree in business administration with a concentration in finance from the Yale School of Management. We believe Ms. Harris is qualified to serve on our board of directors because of her significant corporate finance, operational and business experience.

Richard Hart has served as a member of our Board since April 2017. Mr. Hart is the chair of our nominating and corporate governance committee, and a member of our audit committee, roles he has held since April 2017. He has served as Interim Chief Executive Officer of Vitech, Inc., a private software company, since March 2021, and has served as a director of that company since December 2019. He served as a consultant to various companies during the period from November 2018 until he joined Vitech, Inc. Mr. Hart served as the Chief Strategy Officer of Guidewire Software, Inc., a publicly-traded software company, from March 2018

through November 2018 and served as Guidewire’s Chief Financial Officer from March 2015 through March 2018 (NYSE: GWRE). Since February 2016, Mr. Hart has served as a member of the board of directors of Wonolo, Inc., a private on-demand staffing platform. Since January 2021, Mr. Hart has served as a director of Poema Global Holding Corp., a public special purpose acquisition company (Nasdaq: PPGH). Mr. Hart was a managing director at Deutsche Bank from May 2004 through November 2013. Mr. Hart holds a bachelor’s degree in physics from the University of Pennsylvania and a juris doctorate degree from the New York University School of Law. We believe Mr. Hart is qualified to serve on our board of directors because of his significant corporate finance, legal and business experience.

Class III Directors Continuing in Office until the 2023 Annual Meeting

James R. Scapaco-founded our our company and has served as Chairman of our board of directorsBoard and our chief executive officer since 1992. Prior to his role as our chief executive officer, Mr. Scapa served as secretary and treasurer since our inception in 1985. Mr. Scapa holds a bachelor’s degree in mechanical engineering from Columbia University and a masters of business administration degree from the University of Michigan. We believe that the perspective and experience that Mr. Scapa brings as our chief executive officer and founder uniquely qualifies him to serve as the Chairman of our board of directors. Mr. Scapa is the father of Stephanie Buckner, who became an executive officer of our company in 2021.

Steve Earhart has served as a member of our board of directorsBoard since May 2011. Mr. Earhart is the chair of our audit committee, a position he has held since January 2016, and a member of our compensation committee, a position he has held since January 2015. Mr. Earhart served as a member of the board of directors and audit committee chair of Mi9 Retail, Inc., a private company providing enterprise software solutions to retailers, a position he held from December 2017 to October 2018. Mr. Earhart served as chief financial officer of World

CORPORATE GOVERNANCE MATTERS

Board of Director Composition

Our Board currently consists of seven members. Our directors hold office until their successors have been elected and qualified or until the earlier of their resignation or removal.

We have no formal policy regarding board diversity. Our priority in selection of board members is identification of members who will further the interests of our stockholders through his or her established record of professional accomplishment, the ability to contribute positively to the collaborative culture among board members, knowledge of our business and understanding of the competitive landscape.

Board of Director Meetings

Our Board met six13 times in 2019.2020. Each director attended at least 75% of the aggregate of (i) the total number of meetings of our Board (held during the period for which such director served on the Board) and (ii) the total number of meetings of all committees of our Board on which such director served (during the periods for which the director served on such committee or committees). This is our third Annual Meeting of Stockholders since our initial public offering on October 31, 2017. Altair does not have a formal policy requiring members of the Board to attend our annual meetings. All directors other than Mr. Chouinard attended the 20192020 annual meeting of stockholders.stockholders, which was held remotely.

Director Independence

Because Mr. Scapa controls a majority of our outstanding voting power, we qualify as a “controlled company” under the corporate governance rules of the NASDAQ Stock Market LLC, or NASDAQ. Therefore, we are not required to have a majority of our Board be independent, nor are we required to have an independent compensation committee or an independent nominating function. Notwithstanding our “controlled company” status, we intend to comply with the majority independence and independent compensation committee and nominating function requirements. Regardless of whether we qualify as a “controlled company”, we are required to have a fully independent audit committee subject to certain transition rules. Additionally, audit committee members must also satisfy the independence criteria set forth in Rule10A-3 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”).

Under the rules of the Nasdaq Global Select Market, a director will only qualify as an “independent director” if, in the opinion of that company’s board of directors, that person does not have a relationship that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director. In order to be independent, compensation committee members must not have a relationship with the issuer that is material to the director’s ability to be independent from management in connection with the duties of a compensation committee member.

In order to be considered independent for purposes of Rule10A-3, a member of an audit committee of a listed company may not, other than in his or her capacity as a member of the audit committee, the board of directors or any other board committee, accept, directly or indirectly, any consulting, advisory or other compensatory fee from the listed company or any of its subsidiaries or be an affiliated person of the listed company or any of its subsidiaries.

Our Board has undertaken a review of the independence of each director. Based on information provided by each director concerning his or her background, employment and affiliations, our Board determined that Messrs. Earhart, Hartand Kowal, who is not standing for reelection at the Annual Meeting, and Ms. Harris and Dr. Boyce do not have a relationship that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director and that each of these directors is “independent” as that term is defined under the applicable rules and regulations of the Securities and Exchange

requirements and rules of the Nasdaq Global Select Market. In making these determinations, our Board considered the current and prior relationships that eachnon-employee director has with our company and all other facts and circumstances our Board deemed relevant in determining their independence, including the beneficial ownership of our capital stock by eachnon-employee director, and any transactions involving them described in the section entitled “Transactions“Transactions with Related Persons.Persons.”

Board Committees

Audit Committee

Our audit committee currently consists of Messrs. Earhart, as chair, and Hart and Ms. Harris, each of whom is “independent” as that term is defined under applicable SEC rules and NASDAQ listing standards. Our Board has determined that Mr. Earhart qualifies as an audit committee financial expert within the meaning of SEC regulations and The NASDAQ Marketplace Rules. In making this determination, our Board has considered the formal education and nature and scope of his previous experience, coupled with past and present service on various audit committees. Our audit committee assists our Board in its oversight of our accounting and financial reporting process and the audits of our financial statements.

Our audit committee’s responsibilities include:

All audit services to be provided to us and allnon-audit services to be provided to us by our independent registered public accounting firm must be approved in advance by our audit committee.

Our audit committee operates pursuant to a charter that is available on our website at http://investor.altair.com under the Governance section. Our audit committee met seven12 times in 2019.2020.

Compensation Committee

Our compensation committee currently consists of Ms. Harris, as chair, and Messrs. Earhart and Kowal, who is not standing for reelection at the annual meeting, each of whom is “independent” as that term is defined

under applicable SEC rules and NASDAQ listing

Board, which has responsibility for general oversight of risks, and our standing Board committees. Our Board satisfies this responsibility through full reports by each committee chair regarding the committee’s considerations

EXECUTIVE OFFICERS

The following table sets forth certain information regarding our current executive officers:

Our executive officers are elected by, and serve at the discretion of, our Board. The business experience for the past five years, and in some instances, for prior years, of each of our executive officers is as follows:

James R. Scapa has served as our chief executive officerChief Executive Officer since 1992. For Mr. Scapa’s biography, please see the section above entitled “Class III Nominees for Election for a Term Expiring atContinuing in Office until the 2023 Annual Meeting.”

Brett Chouinard has served as our President since January 1, 2018. For Mr. Chouinard’s biography, please see the section above entitled “Class I Directors Continuing in Office until the 2021 Annual Meeting.”

Howard N. Morof has served as our chief financial officer since February 2013. Mr. Morof also served2018 and as a member of our board of directors from February 2011since 2018. He is also our Chief Operating Officer, a position he has held since January 2010. In January 2021, we announced that Mr. Chouinard will transition to February 2013.the role of serving as one of our Chief Technology Officers by the end of June, 2021. Prior to his role as our chief operating officer, Mr. Chouinard served in various roles with us since 1994. Prior to joining us, Mr. MorofChouinard worked as an engineer at GE Aircraft, a subsidiary of General Electric, Inc. specializing in aircraft engines. Mr. Chouinard holds a bachelor’s degree in mechanical engineering from Michigan Technological University and a master’s degree in mechanical engineering from the University of Cincinnati.

Matthew Brown has served as chief financial officerour Chief Financial Officer since March 16, 2021. Prior to this role, Mr. Brown served from January 1, 2021 to March 16, 2021 as one of North American Bancard, LLC, an independent merchantour Senior Vice Presidents-Finance. Prior to joining our company, Mr. Brown served in Finance leadership roles at NortonLifeLock, a leading consumer cyber safety company, including as Interim Chief Financial Officer from November 2019 to July 2020. Prior to that, he served in Finance leadership roles at Symantec, a leading provider of enterprise security software, from August 2016 to November 2019, most recently as Vice President of Finance and credit card processing company,Chief Accounting Officer. Prior to that, Mr. Brown served as Vice President, Controller for Blue Coat Systems, a provider of advanced web security solutions, from February 2008October 2015 to February 2013.August 2016. Prior to that, Mr. MorofBrown served in various Finance roles at NETGEAR (2010 to 2015) and Brocade Communications (2008 to 2010). He began his career at KPMG, LLP. Mr. Brown is a certified public accountant and holds a master’s degree in taxation from Walsh College and a bachelor’sBachelor of Science degree in business administration from the Walter A. Haas School of Business at the University of Michigan.California, Berkeley.

James P. Dagg has served as our chief technical officerChief Technical Officer of modeling and visualization since January 2014. Prior to this role, Mr. Dagg served from May 2008 to December 2013 as the vice president of our wholly-owned subsidiary solidThinking, Inc. Mr. Dagg holds a bachelor’s degree in mechanical engineering and a master’s degree in applied mechanics from the University of Michigan.

Dr. Uwe Schramm has served as our chief technical officerChief Technical Officer of solvers and optimization since January 2014. Prior to this role, Dr. Schramm served as managing director of Altair GmbH, our wholly-owned German subsidiary, from September 2011 to December 2013. Dr. Schramm holds a master’s degree and a doctorate degree in solid mechanics from the University of Rostock in Rostock, Germany.

Mahalingam Srikanth has served as our chief technical officerChief Technical Officer for HPC and cloud solutions since January 2014. Prior to this role, Mr. Srikanth was a senior vice president at Altair from July 2011 to November 2013 and a vice president at Altair from January 2008 to June 2011. Mr. Srikanth holds a bachelor’s degree in computer science and engineering from Gulbarga University in Gulbarga, India and an executive masters of business administration from the Indian School of Business in Hyderabad, India.

Nelson Dias has served as our chief revenue officerChief Revenue Officer since January 1, 2018, after serving as our Senior VP—Asia Pacific since 2006. Prior to running Altair’s APAC region, Mr. Dias was Managing Director of Altair India

served as our Vice President-Corporate Controller. Prior to these roles, Mr. Gayle began his career at Deloitte & Touche, LLP. Mr. Gayle is a certified public accountant and holds a Bachelor’s degree of Accountancy from the Walsh College.

EXECUTIVE COMPENSATION

Compensation Discussion and Analysis

Introduction

This Compensation Discussion and Analysis provides information regarding the 20192020 compensation program for our principal executive officer, our principal financial officer and the three other most highly-compensated executive officers (our “Named Executive Officers”). For 2019,2020, our Named Executive Officers were:

We believe a critical component of our success has been our company culture, based on our core values of innovation, envisioning the future, communicating honestly and broadly, seeking technology and business firsts, and embracing diversity. This culture is important because it helps attract and retain top people, encourages innovation and teamwork, and enhances our focus on achieving our corporate objectives.

20192020 Business Results

20192020 was a strong year for us, reflecting continuing growth of our software platforms and integration of important acquired technologies.technologies as we confronted the business and personal safety challenges imposed by COVID-19. In 2019:2020:

Pay-for-Performance

We believe our executive compensation program is reasonable, competitive, and appropriately balances the goals of attracting, motivating, rewarding, and retaining our executive officers with the goal of aligning their interests with those of our stockholders. To foster this alignment and to motivate and reward individual initiative and effort, a portion of our executive officers’ target annual total direct compensation opportunity is both performance-based and“at-risk.”

We emphasize variable compensation that appropriately rewards our executive officers, including our Named Executive Officers, through two separate compensation elements:

These variable pay elements assure that a meaningful portion of our executive officers’ target total direct compensation is contingent (rather than fixed) in nature, with the amounts ultimately payable subject to variability above or below target levels commensurate with our actual performance.

We believe that this design provides balanced incentives for our executive officers to drive financial performance and long-term growth.

Stockholder Advisory Votes on Named Executive Officer Compensation

Commencing with this year’s annual meeting of stockholders, we willWe are required to conduct anon-binding stockholder votevotes on the compensation of our Named Executive Officers (commonly known asa “Say-on-Pay” vote). At last year’sour 2019 annual meeting of stockholders, we conducted anon-binding stockholder vote on the frequency of futureSay-on-Pay votes (commonly known as a“Say-When-on-Pay” vote). We recommended that such votes be conducted annually and our stockholders overwhelmingly approved that recommendation. We will hold a Say-on-Pay vote at each annual meeting until the time our stockholders vote to hold the Say-on-Pay vote at a different frequency. See Proposal 23 in this Proxy Statement.

At the 2020 Annual Meeting, approximately 98% of the votes cast in connection with the stockholders advisory vote on compensation of the NEOs were cast in favor of the proposal. We value the opinions of our stockholders. Ourstockholders We have considered this voting result, and our Board of Directors and the Compensation Committee will consider the outcome ofSay-on-Pay votes, as well as feedback received throughout the year, when making compensation decisions for our executive officers, including our Named Executive Officers.

Executive Compensation Philosophy and Objectives

Our executive compensation program is guided by our overarching philosophy of paying for demonstrable performance. Consistent with this philosophy, we have designed our executive compensation program to achieve the following primary objectives:

In addition, we have not adopted policies or employed guidelines for allocating compensation between current and long-term compensation, between cash andnon-cash compensation, or among different forms ofnon-cash compensation.

Compensation-Setting Process

Role of the Compensation Committee

The Compensation Committee discharges the responsibilities of our Board of Directors relating to the compensation of our CEO and oversight of compensation matters for our Named Executive Officers, and recommends for Board of Director approval compensation for thenon-employee members of our Board of Directors. The Compensation Committee has overall responsibility for overseeing our compensation and benefits policies generally, and overseeing and evaluating the compensation plans, policies, and practices applicable to our CEO and other executive officers. In addition, the Compensation Committee makes all final decisions regarding the compensation of our CEO and other executive officers.

In carrying out its responsibilities, the Compensation Committee evaluates our compensation policies and practices with a focus on the degree to which these policies and practices reflect our executive compensation philosophy, develops strategies and makes recommendations that it believes further our philosophy or align with developments in best compensation practices.

The Compensation Committee’s authority, duties, and responsibilities are further described in its charter, which is reviewed annually and revised and updated as warranted. The charter is available on our website at http://investor.altair.com.

The Compensation Committee retains a compensation consultant (as described below) to provide support in its review and assessment of executive compensation.compensation as needed.

Setting Target Total Direct Compensation

The Compensation Committee reviews the base salary levels, annual incentive bonus payments and long-term incentive compensation opportunities of our executive officers, including our Named Executive Officers, and related performance criteria.

These factors provide the framework for compensation decision-making and final decisions regarding the compensation opportunity for each executive officer. No single factor is determinative in setting compensation levels.

The Compensation Committee does not engage in formal benchmarking against other companies’ compensation programs or practices to establish our compensation levels or make specific compensation determinations with respect to our executive officers. Instead, in making recommendations and determinations, the Compensation Committee reviews information summarizing the compensation paid at a representative group of peer companies, to the extent that the executive positions at these companies are considered comparable to our positions and informative of the competitive environment, and more broad-based compensation surveys to gain a general understanding of market compensation levels.

In addition, the Compensation Committee does not weight the foregoing factors in any predetermined manner, nor does it apply formulas in making its compensation determinations. The members of the Compensation Committee consider all of this information in light of their individual experience, knowledge of the Company and its business results, knowledge of the competitive market, knowledge of each executive officer, the advice of their compensation consultant and their business judgment in making their recommendations and determinations.

As part of its oversight function, our Board and our Compensation Committee in particular, along with our management team, considers potential risks when reviewing and approving various compensation programs, including executive compensation. Based on this review, our Compensation Committee believes that our compensation programs, including executive compensation, do not encourage risk taking to a degree that is reasonably likely to have a materially adverse impact on us or our operations.

Role of Management

In discharging its responsibilities, the Compensation Committee works with our CEO, who assists the Compensation Committee by providing information on corporate and individual performance, perspectives on performance issues and recommendations on compensation matters.

Typically, our CEO will make recommendations to the Compensation Committee regarding compensation matters, including adjustments to annual cash compensation, long-term incentive compensation opportunities,

Our Compensation Committee has engaged Compensia, Inc. (“Compensia”), a national compensation consulting firm, to serve as its compensation advisor to advise on executive compensation matters. During 2019,2020, Compensia advised the Compensation Committee with respect to compensation reporting (as last year was the first year in which we provided a Compensation Disclosure & Analysis in our proxy statement), Board compensationexecutive non-equity and the treatment of equity awards on retirement.compensation. Compensia did not provide any services to our company other than the consulting services provided to the Compensation Committee.

The Compensation Committee reviews the objectivity and independence of the advice provided by its compensation consultant on executive compensation matters. With respect to the services provided in 2019,2020, the Compensation Committee evaluated Compensia’s engagement, and based on the six factors for assessing independence and identifying potential conflicts of interest that are set forth in Exchange Act Rule10C-1(b)(4), Rule 5605(d)(3)(D) of the NASDAQ Marketplace Rules, and such other factors as were deemed relevant under the circumstances, determined that its relationship with Compensia and the work of Compensia on behalf of the Compensation Committee did not raise any conflict of interest, and that Compensia is independent.

Competitive Positioning

For purposes of assessing our executive compensation against the competitive market, the Compensation Committee reviews and considers the compensation levels and practices of a select group of peer companies. This compensation peer group consists of technology companies that share one or more characteristics of our company, including annual revenue, market capitalization, geographical location, vertical focus and end market. However, not all criteria may be applicable to each individual peer group member. The Compensation Committee reviews our compensation peer group periodicallyfrom time to time and makes adjustments to its composition as warranted, taking into account changes in both our business and the businesses of the companies in the peer group. We included the following companies in our group of peer companies for 20192020 compensation purposes:

Compensation Elements

In 2019,2020, the principal elements of our executive compensation program, and the purposes for each element, were as follows:

Base Salary

Base salary represents the fixed portion of the compensation of our executive officers, including our Named Executive Officers, and is an important element of compensation intended to attract and retain highly-talented individuals. Generally, we use base salary to provide each executive officer with a specified level of cash compensation during the year with the expectation that he or she will perform his or her responsibilities to the best of his or her ability and in our best interests.

Generally, we establish the initial base salaries of our executive officers througharm’s-length negotiation at the time we hire the individual, taking into account his or her position, qualifications, experience, and the base salaries of our other executive officers. Thereafter, the Compensation Committee reviews the base salaries of our executive officers each year as part of its annual compensation review, with inputrecommendations from our CEO (except with respect to his own base salary) and makes adjustments as it determines to be reasonable and necessary to reflect the scope of an executive officer’s performance, individual contributions and responsibilities, position in the case of a promotion, and market conditions.

The base salaries of our Named Executive Officers for 20192020 were as follows:

Amy Messano joined our companyThe base salaries in 2019.the table above give effect to reductions effected in 2020 in response to COVID -19.

Executive Bonus Program

Each year, we make bonus arrangements with our senior executives (including the Named Executive Officers), other employees who report directly to our CEO, and vice presidents in key positions (the “Executive Bonus Program”). Generally, for the Named Executives other than the CEO, bonus payments under the Executive Bonus Program are calculated starting with a target bonus amount for each participant as recommended by our CEO and approved by the Compensation Committee, multiplied by the achievement of a corporate financial performance metric and then, for each program participant, adjusted for his or her individual performance. For the CEO, the Compensation Committee begins with a target bonus amount and then evaluates the CEO’s performance against certain quantitative and qualitative metrics associated with Company and individual performance.In each case, the Compensation Committee reviews the payment and amount of any award.

For 2019, the Named Executive Officers (other than the CEO)2020, Mr. Morof, Ms. Messano and Dr. Schramm were paid 50% or 60% of their target bonus payment under the Executive Bonus Program in equal monthly installments, with the additional earned bonus paid once final bonus amounts were determined after the end of the year. The CEO and Ms. Saravia did not receive any portion of his bonustheir bonuses until after the final bonus amount wasamounts were determined subsequent toyear-end. No provision was made for repayment of these installments if 20192020 performance objectives were not attained; in fact, the performance objectives utilized by the Compensation Committee in 20192020 were largely attained. Commencing in 2021, bonus payments will not be paid to our executive officers until the final bonus amounts are calculated.

Target Bonus Amounts

For purposes of the Executive Bonus Program, bonus payments are based upon a specific target bonus amount as recommended by our CEO and approved by the Compensation Committee. The CEO participates in the Compensation Committee’s deliberations regarding the target amounts for eligible employees, but does not participate in the deliberations regarding his target bonus.

In February 2019,March 2020, the Compensation Committee reviewed the recommended target bonus amounts for our Named Executive Officers, taking into consideration the factors described in “Compensation-Setting Process – Setting Target Total Direct Compensation” above. Following this review, the Compensation Committee determined to set the target bonus amounts as proposed by our CEO with respect to the Named Executive

Corporate Performance Metric and Individual Performance Metric

Participants in the Executive Bonus Program are eligible to receive a bonus payment in the discretion of the Compensation Committee based upon the attainment of performance objectives as proposed by the CEO and approved by the Compensation Committee and which relate to the financial metrics that are most important to us. For the Named Executive Officers (other than the CEO), the bonus was determined for 20192020 by measurement of (i) Company performance against a variant of adjusted EBITDA that is further adjusted in the discretion of the Compensation Committee to exclude certain revenues and expenses that the Committee believes should not impact compensation results (the “Company Performance Target”); with further consideration and (ii)adjustments given to individual performance. For the CEO, the bonus was determined for 20192020 by measurement against a combination of quantitative and qualitative Company and individual performance metrics designed to promote growth of Company revenues and profitability (the “CEO Metrics”). The Company has chosen not to disclose the Company Performance Target or the CEO Metrics since they are internal standards primarily used to assess compensation, and the Company believes that disclosure of such information would cause competitive harm without adding meaningfully to the understanding of our business or compensation strategy. At the time they were set, the Company Performance Target and the CEO Metrics were perceived by the Compensation Committee to be attainable but requiring significant management effort and achievement in order to be attained.

In all cases, the Compensation Committee reserves the ability to adjust the bonus upwards or downwards after application of these measurement steps. Effectively, the Compensation Committee has the discretion to consider corporate achievements other than those captured by the metrics to be measures of performance, to fund the Executive Bonus Program even if we did not achieve the threshold performance level, and to not make bonus payments even if we achieved the target performance level for the corporate performance objective.

20192020 Executive Bonus Decisions

In February 2020,2021, the Compensation Committee determined that, for the Named Executive Officers, the Company’s performance in 20192020 did not fully meet expectations. The Compensation Committee reviewed the individual performance of each of the Named Executive Officers based on an evaluation provided by our CEO of their performance. For the CEO, the Compensation Committee discussed with the CEO his own individual performance against metrics discussed with our CEO throughout 2019.2020.

Based on these determinations, the Compensation Committee approved the following cash bonus payments for our Named Executive Officers for 2019:2020:

Long-term incentive compensation opportunities in the form of equity awards are granted to our CEO and our other executive officers by the Compensation Committee. The amount and forms of such equity awards are determined by the Compensation Committee after considering the factors described in “Compensation-Setting Process” above. The amounts of the equity awards are also intended to provide resulting target total direct compensation opportunities that the Compensation Committee believes are reasonable.

In March 2019,2020, the Compensation Committee determined that the equity awards to be granted to our executive officers, including our Named Executive Officers, should be in the form of time-based RSU awards that may vest and be settled for shares of our Class A Common Stock and options to acquire our Class A Common Stock. The number of shares of our Class A Common Stock subject to the RSU awards and options granted to our executive officers (other than the CEO) were proposed by the CEO and approved by the Compensation Committee after considering the factors described in “Compensation-Setting Process” above. All of the RSU awards and options were granted in March 20192020 with respect to 20182019 performance. Under applicable SEC regulations, such equity awards are included in the Summary Compensation Table below as 20192020 compensation.

The equity awards granted to our Named Executive Officers in 2019March 2020 were as follows:

In June 2020, the Compensation Committee authorized the grant of additional options to acquire our Class A Common Stock to certain of our employees, including certain Named Executive Officers. The Compensation Committee granted one half of the options in June 2020 and one half of the options in December 2020. The number of shares of our Class A Common Stock subject to the options granted to our executive officers were proposed by the CEO and approved by the Compensation Committee. Our CEO did not receive any of these options. All of the options were granted to provide long-term incentives toward the Company’s growth and increase stockholder value. Half of each option vested two years after the grant date, with the balance of such option vesting three years after the grant date, contingent upon each optionee’s remaining continuously employed by us through each applicable vesting date. The options were intended to incentivize key employees during a year when our company was required to meet the challenges imposed upon our employees, our business, our customers and others by COVID-19 and other factors.

The equity awards granted to our Named Executive Officers in June and December 2020 were as follows:

In March 2020,2021, the Compensation Committee determined that the equity awards to be granted to our executive officers, including our Named Executive Officers, should be a combination of time-based RSU awards that may vest and be settled for shares of our Class A Common Stock and options to acquire our Class A Common Stock. The number of shares of our Class A Common Stock subject to the RSU awards and options

granted to our executive officers were proposed by the CEO and approved by the Compensation Committee (with Mr. Scapa participating in determinations regarding the grants other than the grants made to him) after considering the factors described in “Compensation-Setting Process” above. All of the RSU awards and options were granted in March 20202021 with respect to 20192020 performance. Under applicable SEC regulations, such equity awards are not included in the Summary Compensation Table below as 20192020 compensation.

We determine the incremental cost of the personal use of our corporate airplane based on the variable operating costs to us, which includes, if applicable, (i) landing, ramp, and parking fees and expenses; (ii) crew travel expenses; (iii) supplies and catering; (iv) aircraft fuel and oil expenses per hour of flight; (v) any customs, foreign permit, and similar fees; (vi) crew travel; and (vii) passenger ground transportation. Because our corporate airplane is intended to be used primarily for business travel, this methodology excludes fixed costs that do not change based on usage, such as purchase or lease costs and costs of maintenance and upkeep.

Our Named Executive Officers incur taxable income for all personal use of our corporate airplane. We do not grant bonuses to cover, reimburse, or otherwise “gross-up” any income tax owed for personal travel on our corporate aircraft.

Currently, we do not view perquisites or other personal benefits as a significant component of our executive compensation program. Accordingly, we do not provide any other significant perquisites or other personal benefits to our executive officers, including our Named Executive Officers, except as generally made available to our employees, or in situations where we believe it is appropriate to assist an individual in the performance of his or her duties, to make him or her more efficient and effective, and for recruitment and retention purposes.

In the future, we may provide perquisites or other personal benefits in limited circumstances. All future practices with respect to perquisites or other personal benefits will be approved and subject to periodic review by the Compensation Committee.

Post-Employment Compensation

We have not providedentered into executive severance payments and benefits toagreements with each of our Named Executive Officers, other than to Mr. Morof pursuant(the “Severance Agreements”). The Severance Agreements each provide for severance protections in the event of a termination by the Company other than for “cause” or in the event of a resignation by the applicable Named Executive Officer for “good reason” during the period between the execution of the Severance Agreements and the one-year anniversary of a “change in control.” In such event, the executive generally would be entitled to his amended and restated employment offer letter andthe following (in lieu of any other severance payments to which the executive may be entitled), subject to execution of a release of claims (other than with respect to certain amounts that accrued prior to termination):

The Severance Agreements provide that to the extent any amount or benefit to be provided pursuant to the applicable Severance Agreement or otherwise would be treated as an “excess parachute payment,” as that phrase is defined in Section 280G of the Code, then the amounts and benefits the executive would otherwise receive would either be (i) paid or allowed in full; or (ii) reduced (but not below zero) to the maximum amount which may be paid without causing any amount or benefit to be nondeductible to the Company under Section 280G of the Code, or subject the executive to an excise tax under Section 4999 of the Code, whichever would result in the executive’s receipt, on an after-tax basis, of the greatest amount of amounts and benefits.

In connection with the termination of Mr. Morof’s services as of the close of business on March 16, 2021, we entered into a transition and separation and general release agreement with him on January 15, 2021. The separation agreement with Mr. Morof provided, among other things, for Mr. Morof to receive the following:

In addition, the separation agreement with Mr. Morof provided that upon the effectiveness of his reaffirmation of his release of claims any outstanding unvested stock options and restricted stock units held by Mr. Morof will vest to the extent that such stock options and restricted stock units would have vested had Mr. Morof remained employed with us through March 16, 2022. Accordingly, 8,847 stock options and 2,337 restricted stock units held by Mr. Morof vested upon the effectiveness of his reaffirmation. Based upon the closing price of our employ under certain circumstances to facilitate her transition to new employment.Class A common stock of $60.02 on March 24, 2021, such stock options had a value of $387,317 and such restricted stock units had a value of $140,237.

We do not use excise tax payments(or “gross-ups”) relating to a change in control of the Company and have no such obligations in place with respect to any of our Named Executive Officers.

For a summary of the material terms and conditions ofmore information about the post-employment compensation arrangements we maintained with our Named Executive Officers during 2019,2020, as well as an estimate of the potential payments and benefits that they would have been eligible to receive if a hypothetical change in control or other trigger event had occurred on December 31, 2019,2020, see “Potential Payments Upon Termination or Change in Control” below.

Other Compensation Policies

Hedging and Pledging Transactions

Under our Insider Trading Policy, all of our executive officers, thenon-employee members of our Board of Directors, and certain other employees as designated by our Compliance Officer are prohibited from engaging in any of the following transactions:

Deductibility of Executive Compensation

Generally, Section 162(m) of the Internal Revenue Code disallows publicly held corporations a tax deduction for federal income tax purposes for remuneration paid to certain “covered employees” in a taxable year to the extent that remuneration exceeds $1 million per calendar year for a covered employee. Given the net operating loss carryforwards and tax credits available to our company, the Compensation Committee does not believe that Section 162(m) will be a principal factor in determining executive compensation for the foreseeable future.

When and if Section 162(m) becomes more relevant to us in the future, the Compensation Committee may, in its judgment, approve compensation for our Named Executive Officers that is not deductible for federal income tax purposes when it believes that such compensation is in the best interests of the Company and our stockholders.

Accounting for Stock-Based Compensation

The Compensation Committee takes accounting considerations into account in designing compensation plans and arrangements for our executive officers and other employees. Chief among these is Financial Accounting Standards Board Accounting Standards Codification Topic 718 (“ASC Topic 718”), the standard which governs the accounting treatment of certain stock-based compensation. Among other things, ASC Topic 718 requires us to record a compensation expense in our income statements for all equity awards granted to our executive officers and other employees, based on the grant date “fair value” of these awards. This calculation is performed for accounting purposes and reported in the compensation tables below, even though recipients may never realize any value from their equity awards. ASC Topic 718 also requires us to recognize the compensation cost of our stock-based compensation awards in our income statements over the period that an executive officer is required to render service in exchange for the equity based award.

Compensation Committee Report

The information contained in the following report of Altair’s compensation committee is not considered to be “soliciting material,” “filed” or incorporated by reference in any past or future filing by us under the Securities Exchange Act of 1934, as amended, or the Securities Act of 1933, as amended, unless and only to the extent that Altair specifically incorporates it by reference.

The compensation committee establishes the compensation programs for our named executive officers. In connection with such responsibility, the compensation committee has reviewed and discussed with management the Compensation Discussion and Analysis included in this Proxy Statement.

In reliance on the review and discussions referred to above, the Compensation Committee has recommended to the Board of Directors that this Compensation Discussion and Analysis be incorporated by reference into the Annual Report onForm 10-K for the year ended December 31, 20192020 and included in this Proxy Statement.

Submitted by the Compensation Committee

Trace Harris, Chair

Steve Earhart

Jan Kowal

20192020 Summary Compensation Table

Our Named Executive Officers for the year ended December 31, 20192020 are: James R. Scapa, Howard N. Morof, Brett Chouinard,Gilma Saravia, Amy Messano and Uwe Schramm. Mr. Morof served as our Chief Financial Officer through March 16, 2021. At the close of business on March 16, 2021, Matthew Brown became our Chief Financial Officer. The following table provides information regarding the total compensation for services rendered in all capacities earned by our Named Executive Officers for the fiscal years ended December 31, 2020, 2019 2018 and 2017.2018.

Narrative Disclosure to Summary Compensation Table

Employment Agreements with our Named Executive Officers

James Scapa Brett Chouinard and Uwe Schramm

Mr. Scapa Mr. Chouinard and Dr. Schramm are not a party to an employment agreement or offer letter with Altair.

Howard N. Morof Employment Letter

We entered into an employment letter with Howard N. Morof, our former chief financial officer, on January 10, 2013, which was subsequently amended and restated on July 19, 2017, to, among other things, reflect his current compensation and to add language to address provisions of Section 409A of the Internal Revenue Code of 1986, as amended (the “Code”). The employment letter hashad an indefinite term, and Mr. Morof’s employment iswas at-will.

During his employment with us, Mr. Morof iswas entitled to an automobile allowance and he is currentlywas eligible to earn annual incentive compensation payable from our Executive Bonus Program applicable to other members of our senior executive team. He iswas also eligible to earn a matching contribution to our 401(k) Plan as determined annually by us. His compensation as described in this paragraph may be adjustedwas subject to adjustment year to year as described in the section entitled “Compensation, Discussion and Analysis”.

If Mr. Morof resigns from employment for good reason, or is terminated without cause, he is entitled to 12 months of base salary plus any accrued annual bonus and a prorated annual bonus forIn connection with the year of termination. He is also entitled to continued participation in our employee benefit programs, as if still employed as chief financial officer, during that 12 month period.

Pursuant to Mr. Morof’s employment letter, if Mr. Morof is involuntarily terminated for any reason other than cause or if Mr. Morof voluntarily terminates his employment for good reason within the one month prior to, or twelve months following, a change in control (as defined in our 2012 Plan (as defined under the heading “Equity Compensation Plans” below)) Mr. Morof will also be entitled to aone-time special bonus equal to $500,000, payable in full within three business days following such termination.

For purposestermination of Mr. Morof’s employment letter, “cause” means the occurrence of any of the following:services, we entered into a transition and separation and general release agreement with him on January 15, 2021. For information regarding this agreement, see “Compensation Disclosure and Analysis – Post-Employment Compensation”.

For purposes of Mr. Morof’s employment letter, “good reason” means the occurrence of any of the following:

For a summary of the material terms and conditions of the post-employment compensation arrangements we maintained with our Named Executive Officers during 2020, as well as an estimate of the potential payments and benefits that they would have been eligible to receive if a hypothetical change in control or other trigger event had occurred on December 31, 2020, please also see “Potential Payments Upon Termination or Change in Control” below.

Potential Payments Upon Termination or Change in Control

The table below reflects, as applicable, cash severance, equity acceleration, and continuation of employment benefits payable to our Named Executive Officers in connection with (1)(A) an involuntary termination of employment (i.e., a termination without cause or resignation for good reason) other than in connection with a change in control of our company, (2)(B) a change in control of our company and no termination of employment (assuming that all equity awards will not be assumed, continued or substituted by the successor entity), and (3)(C) an involuntary termination (i.e., a termination without cause or resignation for good reason) in connection with a change in control of our company, assuming for each of (1)(A), (2)(B) and (3)(C) that the applicable triggering event(s) occurred on December 31, 20192020, and that the above-mentioned severance agreements were in effect on that date:date. Generally, however, on any termination, the applicable Named Executive Officer would have received accrued and unpaid salary and other benefits until the date of termination. In addition, the table below assumes that our Named Executive Officers comply with all applicable restrictive covenants.

Grants of Plan-Based Awards in Fiscal Year 20192020

The following table provides information regarding plan-based awards granted to our Named Executive Officers during 2019.2020.

Outstanding Equity Awards at FiscalYear-End

The following table sets forth information regarding outstanding equity awards held by our Named Executive Officers as of December 31, 2019.2020.