The following table summarizes the aggregate workers' compensation reserve activity (in thousands):


	Years Ended December 31,
	2023			2022			2021
Beginning balance
Workers' compensation claims liabilities	$	215,987		$	279,407		$	357,746
Add: claims expense accrual
Current period		16,731			19,146			75,786
Prior periods		(12,147	)		(11,337	)		(9,225	)
		4,584			7,809			66,561
Less: claim payments related to
Current period		3,260			4,450			15,063
Prior periods		52,570			67,581			129,138
		55,830			72,031			144,201
Change in claims incurred in excess of retention limits		3,022			802			(699	)
Ending balance
Workers' compensation claims liabilities	$	167,763		$	215,987		$	279,407

The Company provides workers’ compensation coverage for client employees primarily through arrangements with fully licensed, third-party insurers (the “insured program”). Under this program, carriers issue policies or afford coverage to the Company’s clients under a program maintained by the Company. Approximately 84% of the Company’s workers’ compensation exposure is covered through the insured program.

Effective July 1, 2021, the Company entered into a new arrangement for its insured program, whereby third-party insurers assumed all risk of loss for claims incurred from July 1, 2021 to June 30, 2022 (the “2021-2022 Policy”). The arrangement for the insured program was extended for claims incurred from July 1, 2022 to June 30, 2023 (the “2022-2023 Policy”) and for claims incurred from July 1, 2023 to June 30, 2024 (the “2023-2024 Policy”).

The 2021-2022 Policy, 2022-2023 Policy, and 2023-2024 Policy allow for premium adjustments depending on overall policy performance. If claims develop favorably, BBSI can participate in savings up to $20.0 million, $22.5 million, and $28.5 million for the 2021-2022 Policy, 2022-2023 Policy, and 2023-2024 Policy, respectively. If claims develop adversely, additional premium may be charged up to $7.5 million under the 2021-2022 Policy. No additional premiums may be charged if claims develop adversely under the 2022-2023 Policy and the 2023-2024 Policy.

For the above policies, premium amounts incurred but not paid are classified as either current or long-term based on the expected timing of the payments and are recorded in current premium payable and long-term premium payable on the consolidated balance sheets.

For claims incurred under the insured program prior to July 1, 2021, the Company retains risk of loss up to the first $3.0 million per occurrence on policies issued after June 30, 2020 and $5.0 million per occurrence on policies issued before that date.

On June 29, 2020, the Company entered into a loss portfolio transfer agreement (“LPT 1”) to remove all outstanding workers’ compensation claims obligations for claims incurred under its insured program between February 1, 2014 and December 31, 2017.

On June 30, 2021, the Company entered into a loss portfolio transfer agreement (“LPT 2”) to remove all remaining outstanding workers’ compensation claims obligations for client policies issued under its insured program up to June 30, 2018.

The Company is required to maintain minimum collateral levels for certain policies issued under the insured program, which is held in a trust account (the “trust account”). The balance in the trust account was $210.9 million and $188.2 million at December 31, 2023 and December 31, 2022, respectively. The trust account balance is included as a component of the current and long-term restricted cash and investments in the Company’s consolidated balance sheets.

The Company is a self-insured employer with respect to workers' compensation coverage for all employees, including employees of PEO clients that elect to participate in our workers’ compensation program, working in Colorado, Maryland and Oregon. In the state of Washington, state law allows only the Company's staffing services and internal management employees to be covered under the Company's self-insured workers' compensation program. The Company also operates a wholly owned, fully licensed insurance company, Ecole, which provides workers’ compensation coverage to client employees working in Arizona and Utah. Approximately 16% of the Company’s workers’ compensation exposure is covered through self-insurance or Ecole (the “self-insured programs”).

For all claims incurred under the Company’s self-insured programs, the Company retains risk of loss up to the first $3.0 million per occurrence, except in Maryland and Colorado, where the Company’s retention per occurrence is $1.0 million and $2.0 million, respectively. For claims incurred under the Company’s self-insured programs prior to July 1, 2020, the Company retains risk of loss up to the first $5.0 million per occurrence, except in Maryland and Colorado, where the retention per occurrence is $1.0 million and $2.0 million, respectively.

The states of Maryland, California, Oregon, Colorado, Washington, and Delaware required the Company to maintain collateral totaling $48.1 million and $54.5 million at December 31, 2023 and 2022, respectively, to cover potential workers’ compensation claims losses related to the Company’s current and former status as a self-insured employer. At December 31, 2023, the Company provided surety bonds totaling $48.1 million.

The Company provided a total of $167.8 million and $216.0 million at December 31, 2023 and 2022, respectively, as an estimated future liability for unsettled workers' compensation claims liabilities. Of this amount, $6.0 million and $3.0 million on December 31, 2023 and 2022, respectively, represent case reserves and IBNR in excess of the Company’s retention. The accrual for costs incurred in excess of retention limits is offset by a receivable from insurance carriers of $6.0 million and $3.0 million at December 31, 2023 and 2022, respectively, included in other assets in the consolidated balance sheets.