Custom Truck One Source (CTOS) president receives 24,796-share performance award

Rhea-AI Filing Summary

Custom Truck One Source, Inc. reported that President – Rentals Rich Thomas R. received an equity award tied to prior performance. He acquired 24,796 shares of Common Stock at no cash price through performance stock units earned for a performance period ending on December 31, 2025. After this grant, he holds 311,173 shares directly, with the new shares still subject to time-based vesting until December 31, 2026.

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

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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^*

Rich Thomas R.

(Last) (First) (Middle)

7701 INDEPENDENCE AVE

(Street)

KANSAS CITY MISSOURI 64125

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Custom Truck One Source, Inc. [ CTOS ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	President - Rentals

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
02/23/2026

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

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

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

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	02/23/2026		A		24,796(1)	A	$0	311,173	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. Represents an award of performance stock units ("PSUs") earned as a result of the achievement of performance criteria pursuant to PSU awards with a performance period that ended on December 31, 2025, as certified by the compensation committee of the Issuer's board of directors on February 23, 2026. Such shares remain subject to a time-based vesting condition, which will be satisfied on December 31, 2026.

	/s/ Paul M. Jolas, Attorney-in-fact	03/26/2026
	** 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.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transaction did CTOS executive Rich Thomas report?

Rich Thomas reported receiving 24,796 shares of Custom Truck One Source common stock as an equity award. The shares were earned through performance stock units and granted at no cash cost as part of his executive compensation.

Was the CTOS Form 4 transaction a stock purchase or a compensation award?

The CTOS Form 4 shows a compensation-related award, not an open-market purchase. Rich Thomas received 24,796 shares through performance stock units, reflecting achievement of performance criteria rather than buying shares in the market.

What performance period applied to Rich Thomas’s CTOS stock award?

The performance stock units were earned based on criteria measured over a performance period ending December 31, 2025. The compensation committee certified the results on February 23, 2026, triggering the share award reflected in the Form 4 filing.

Do the newly awarded CTOS shares vest immediately for Rich Thomas?

The awarded shares do not fully vest immediately. Although 24,796 shares were earned and granted, they remain subject to a time-based vesting condition that will be satisfied on December 31, 2026, extending the retention period.

How many CTOS shares does Rich Thomas own after this Form 4 transaction?

Following the award, Rich Thomas directly holds 311,173 shares of Custom Truck One Source common stock. This total includes the 24,796 shares granted through performance stock units, which are still subject to time-based vesting until December 31, 2026.

What does transaction code "A" mean in the CTOS Form 4 for Rich Thomas?

Transaction code “A” on the CTOS Form 4 indicates an acquisition as a grant, award, or similar transaction. In this case, it reflects a performance-based stock award of 24,796 shares, not a discretionary open-market stock purchase or sale.