We participate in multiple healthcare plans, the largest of which is partially self-funded with an insurance company paying benefits in excess of stop loss limits per individual/family. Our healthcare benefit expense (net of employee contributions) was $8.4 million and $7.4 million for the three months ended March 31, 2024 and 2023, respectively. An accrual for estimated healthcare claims incurred but not reported (“IBNR”) is included within accrued compensation on the Condensed Consolidated Balance Sheets and was $4.4 million and $3.9 million as of March 31, 2024 and December 31, 2023, respectively.

Workers’ compensation known claims and IBNR reserves included on the Condensed Consolidated Balance Sheets were as follows (in millions):


	March 31, 2024		December 31, 2023
Included in other current liabilities	$	8.6	$	9.5
Included in other long-term liabilities	21.0		17.0
	$	29.6	$	26.5

We also had an insurance receivable for claims that exceeded the stop loss limit under our self-insured policies as well as claims under our fully insured policies included on the Condensed Consolidated Balance Sheets. This receivable offsets an equal liability included within the reserve amounts noted above and was as follows (in millions):

We participate in multiple 401(k) plans, whereby we provide a matching contribution of wages deferred by employees and can also make discretionary contributions to each plan. Certain plans allow for discretionary employer contributions only. These plans cover substantially all our eligible employees. We recognized 401(k) plan expenses of $1.0 million and $0.9 million during the three months ended March 31, 2024 and 2023, respectively. These expenses are included in administrative expenses on the accompanying Condensed Consolidated Statements of Operations and Comprehensive Income.

We participate in various multiemployer pension plans under collective bargaining agreements in Washington, Oregon, California and Illinois with other companies in the construction industry. These plans cover our union-represented employees and contributions to these plans are expensed as incurred. These plans generally provide for retirement, death and/or termination benefits for eligible employees within the applicable collective bargaining units, based on specific eligibility/

participation requirements, vesting periods and benefit formulas. We do not participate in any multiemployer pension plans that are considered to be individually significant.

We periodically grant shares of our common stock to non-employee members of our board of directors and our employees. During each of the three months ended March 31, 2024 and 2023, we did not grant any such shares under our 2023 Omnibus Incentive Plan to non-employee members of our board of directors or employees.

During the three months ended March 31, 2024, we issued approximately 67 thousand shares of our common stock to certain officers, which vest in two equal installments on each of April 20, 2025 and April 20, 2026. In addition, during the three months ended March 31, 2024, we established, and our board of directors approved, performance-based targets in connection with common stock awards to be issued to certain officers in 2025 contingent upon achievement of these targets.

In addition, there are long-term performance-based restricted stock awards to be issued to certain employees annually through the 2024 performance period contingent upon achievement of certain performance targets. These awards are accounted for as liability-based awards since they represent a predominantly-fixed monetary amount that will be settled with a variable number of common shares annually. These awards will vest in 2025 and are included in other current liabilities on the Condensed Consolidated Balance Sheets. During the three months ended March 31, 2024 and 2023, we issued approximately four thousand and eight thousand shares of our common stock, respectively.

During 2023, we established, and our board of directors approved, performance-based restricted stock units in connection with common stock awards to be issued to certain employees in 2024 based upon achievement of a performance target. These units will be accounted for as equity-based awards that will be settled with a fixed number of common shares.


	Common Stock Awards			Performance-Based Stock Awards			Performance-Based Restricted Stock Units
	Awards	Weighted Average Grant Date Fair Value Per Share		Awards	Weighted Average Grant Date Fair Value Per Share		Units	Weighted Average Grant Date Fair Value Per Share
Nonvested awards/units at December 31, 2023	116,482	$	103.02	148,459	$	108.83	14,382	$	111.71
Granted	4,105	205.96		35,320	205.96		—	—
Vested	(3,758)	101.35		—	—		—	—
Forfeited/Cancelled	(245)	102.77		—	—		(111)	111.61
Nonvested awards/units at March 31, 2024	116,584	$	106.70	183,779	$	127.49	14,271	$	111.71


	Three months ended March 31,
	2024		2023
Common Stock Awards	$	1.2	$	1.4
Non-Employee Common Stock Awards	0.2		0.1
Performance-Based Stock Awards	1.9		1.6
Liability Performance-Based Stock Awards	0.4		—
Performance-Based Restricted Stock Units	0.4		0.3
	$	4.1	$	3.4

Administrative stock compensation expense includes all stock compensation earned by our administrative personnel, while cost of sales and selling stock compensation represents all stock compensation earned by our installation and sales employees, respectively.


	As of March 31, 2024
	Unrecognized Compensation Expense on Unvested Awards		Weighted Average Remaining Vesting Period
Common Stock Awards	$	6.7	1.6 years
Performance-Based Stock Awards	12.3		2.1 years
Performance-Based Restricted Stock Units	0.1		0.1 years
Total unrecognized compensation expense related to unvested awards	$	19.1

Total unrecognized compensation expense is subject to future adjustments for forfeitures. This expense is expected to be recognized over the remaining weighted-average period shown above on a straight-line basis except for the Performance-Based Stock Awards which uses the graded-vesting method. Shares forfeited are returned as treasury shares and available for future issuances.

During the three months ended March 31, 2024, our employees surrendered approximately one thousand shares of our common stock to satisfy tax withholding obligations arising in connection with the vesting of common stock awards issued under our 2023 and 2014 Omnibus Incentive Plans.

In May 2023, our stockholders approved a new 2023 Omnibus Incentive Plan which became effective on May 26, 2023. All future awards as of this date will be granted under the new plan, and awards granted previously under the 2014 Omnibus Incentive Plan will not be modified or impacted by this adoption. As of March 31, 2024, approximately 1.8 million of the 2.1 million shares of common stock authorized for issuance were available for issuance under the 2023 Omnibus Incentive Plan.