Michael J. Desmarais - 10 Mar 2026 Form 4 Insider Report for COSTAR GROUP, INC. (CSGP)

Role: Chief Human Resources Officer
Signature: /s/ Gene Boxer, Attorney-in-Fact
Issuer symbol: CSGP
Transactions as of: 10 Mar 2026
Net transactions value: $0
Form type: 4
Filing time: 11 Mar 2026, 17:17:59 UTC
Previous filing: 03 Mar 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
DESMARAIS MICHAEL J	Chief Human Resources Officer	C/O COSTAR GROUP, INC., 1201 WILSON BLVD., ARLINGTON	/s/ Gene Boxer, Attorney-in-Fact	11 Mar 2026	0001925959

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	CSGP	Common Stock, par value $0.01 per share	Award		+17,676	+24%		90,598	10 Mar 2026	Direct	F1

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Pursuant to the Management Stock Purchase Plan, all or a portion of the reporting person's annual cash incentive amount was converted to Deferred Stock Units (each equivalent to one share of common stock) at $46.34 per unit, and the Company awarded the reporting person Restricted Stock Units that vest in full after four years for an equal number of shares of common stock.