Initial Statement of Beneficial Ownership (3)

FORM 3	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES	OMB APPROVAL OMB Number: 3235-0104 Estimated average burden hours per response... 0.5
	Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person ^*

Buckner Stephanie

2. Date of Event Requiring Statement (MM/DD/YYYY) 1/4/2021

3. Issuer Name and Ticker or Trading Symbol

Altair Engineering Inc. [ALTR]

(Last) (First) (Middle)

C/O ALTAIR ENGINEERING INC., 1820 E. BIG BEAVER ROAD

4. Relationship of Reporting Person(s) to Issuer (Check all applicable)

_____ Director _____ 10% Owner
___X___ Officer (give title below) _____ Other (specify below)
See Remarks /

(Street)

TROY, MI 48083

(City) (State) (Zip)

5. If Amendment, Date Original Filed(MM/DD/YYYY)

6. Individual or Joint/Group Filing(Check Applicable Line)

_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Class A Common Stock	5988 ⁽¹⁾	D
Class A Common Stock	3543 ⁽²⁾	I	By husband

*Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)*
1. Title of Derivate Security (Instr. 4)	2. Date Exercisable and Expiration Date (MM/DD/YYYY)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
1. Title of Derivate Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security		6. Nature of Indirect Beneficial Ownership (Instr. 5)
Stock Option (right to buy)	⁽³⁾	6/9/2027	Class A Common Stock	300	$5.18	D
Stock Option (right to buy)	⁽⁴⁾	3/11/2030	Class A Common Stock	935	$30.15	D
Stock Option (right to buy)	⁽⁵⁾	6/2/2030	Class A Common Stock	22500	$39.82	D
Stock Option (right to buy)	⁽⁶⁾	12/2/2030	Class A Common Stock	22500	$52.03	D
Stock Option (right to buy)	⁽⁷⁾	6/2/2030	Class A Common Stock	6000	$39.82	I	By husband
Stock Option (right to buy)	⁽⁸⁾	12/2/2030	Class A Common Stock	6000	$52.03	I	By husband

Explanation of Responses:
(1)	Includes 2,250 Class A Common Stock restricted stock units that are unvested.
(2)	Includes 3,050 Class A Common Stock restricted stock units that are unvested.
(3)	The options vest in 4 equal annual installments commencing on June 9, 2018.
(4)	The options vest in 4 equal annual installments commencing on March 11, 2021.
(5)	On June 2, 2020, the Reporting Person was granted options covering 22,500 shares of Class A Common Stock. Of such options, options covering 11,250 shares vest on June 2, 2022 and options covering 11,250 shares vest on June 2, 2023.
(6)	On December 2, 2020, the Reporting Person was granted options covering 22,500 shares of Class A Common Stock. Of such options, options covering 11,250 shares vest on December 2, 2022 and options covering 11,250 shares vest on December 2, 2023.
(7)	On June 2, 2020, the Reporting Person's husband was granted options covering 6,000 shares of Class A Common Stock. Of such options, options covering 3,000 shares vest on June 2, 2022 and options covering 3,000 shares vest on June 2, 2023.
(8)	On December 2, 2020, the Reporting Person's huband was granted options covering 6,000 shares of Class A Common Stock. Of such options, options covering 3,000 shares vest on December 2, 2022 and options covering 3,000 shares vest on December 2, 2023.

Remarks:
Senior Vice President, Customer Engagement & Corporate Development

Exhibit List
Exhibit 24 - Power of Attorney

Reporting Owners
Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
Buckner Stephanie C/O ALTAIR ENGINEERING INC. 1820 E. BIG BEAVER ROAD TROY, MI 48083			See Remarks