CoStar Group (CSGP) CAO awarded 4,374 deferred and restricted units

Rhea-AI Filing Summary

CoStar Group, Inc. reported that Chief Accounting Officer Cynthia Cammett received an award of 4,374 shares of common stock as compensation. Under the Management Stock Purchase Plan, part of her annual cash incentive was converted into Deferred Stock Units at $46.34 per unit, and she was granted an equal number of Restricted Stock Units that vest in full after four years. Following this grant, she directly holds 26,342 shares of CoStar common stock.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Cann Cynthia Cammett

(Last) (First) (Middle)

C/O COSTAR GROUP, INC.

1201 WILSON BLVD.

(Street)

ARLINGTON VA 22209

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
COSTAR GROUP, INC. [ CSGP ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Accounting Officer

3. Date of Earliest Transaction (Month/Day/Year)
03/10/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

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 Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock, par value $0.01 per share	03/10/2026		A		4,374	A	(1)	26,342	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. 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.

Remarks:

	/s/ Gene Boxer, Attorney-in-Fact	03/11/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction did CoStar Group (CSGP) report for Cynthia Cammett?

CoStar Group reported that Chief Accounting Officer Cynthia Cammett received 4,374 shares of common stock as compensation. The award combined Deferred Stock Units and Restricted Stock Units granted under the Management Stock Purchase Plan instead of paying that portion of her annual cash incentive in cash.

How many CoStar (CSGP) shares does Cynthia Cammett hold after this Form 4?

After the reported award, Cynthia Cammett directly holds 26,342 CoStar common shares. This reflects the addition of 4,374 shares granted through Deferred Stock Units and Restricted Stock Units under the company’s Management Stock Purchase Plan in lieu of part of her annual cash incentive.

Was Cynthia Cammett’s CoStar (CSGP) award an open-market stock purchase?

No, the award was not an open-market purchase. It was a compensation-related acquisition where part of her annual cash incentive was converted into Deferred Stock Units and matched with Restricted Stock Units, all granted by CoStar under its Management Stock Purchase Plan.

At what price were Cynthia Cammett’s CoStar (CSGP) Deferred Stock Units converted?

Her Deferred Stock Units were converted at $46.34 per unit, each equivalent to one CoStar common share. This price was used to convert a portion of her annual cash incentive into equity-based compensation, aligning her interests more closely with shareholders over time.

When do Cynthia Cammett’s CoStar (CSGP) Restricted Stock Units vest?

The Restricted Stock Units awarded to Cynthia Cammett vest in full after four years. Until vesting, she does not receive the underlying CoStar common shares, which keeps the award tied to continued service and longer-term company performance during that period.