EMPLOYEE BENEFIT PLANS (Tables)

12 Months Ended

Dec. 31, 2023

POSTRETIREMENT BENEFIT PLANS

Schedule of changes in benefit obligations and plan assets and disclosure of funded status and accumulated benefit obligation of nonunion defined benefit plans

	Supplemental				Postretirement
	Benefit Plan				Health Benefit Plan
	2023		2022		2023		2022
	(in thousands)
Change in benefit obligations
Benefit obligations, beginning of year	$	338	$	381	$	12,534	$	16,992
Service cost		—		—		78		156
Interest cost		16		7		599		441
Actuarial (gain) loss (1)		4		(50)		1,137		(4,392)
Benefits paid		—		—		(680)		(663)
Benefit obligations, end of year		358		338		13,668		12,534
Change in plan assets
Fair value of plan asset, beginning of year		—		—		—		—
Employer contributions		—		—		680		663
Benefits paid		—		—		(680)		(663)
Fair value of plan assets, end of year		—		—		—		—
Funded status at period end	$	(358)	$	(338)	$	(13,668)	$	(12,534)
Accumulated benefit obligation	$	358	$	338	$	13,668	$	12,534

(1) The actuarial losses on the SBP and postretirement health benefit plan for 2023 were primarily related to decreases in the discount rates used to remeasure the plans’ obligations at December 31, 2023 versus the prior year, and the actuarial gains for 2022 were primarily related to increases in the discount rates used in the remeasurement at December 31, 2022.

Schedule of amounts recognized in the consolidated balance sheets related to nonunion defined benefit plans

	Supplemental				Postretirement
	Benefit Plan				Health Benefit Plan
	2023		2022		2023		2022
Current portion of pension and postretirement liabilities	$	—	$	—	$	(707)	$	(676)
Pension and postretirement liabilities, less current portion		(358)		(338)		(12,961)		(11,858)
Liabilities recognized	$	(358)	$	(338)	$	(13,668)	$	(12,534)

Summary of the components of net periodic benefit cost (credit)

	Supplemental						Postretirement
	Benefit Plan						Health Benefit Plan
	2023		2022		2021		2023		2022		2021
	(in thousands)
Service cost	$	—	$	—	$	—	$	78	$	156	$	192
Interest cost		16		7		4		599		441		427
Amortization of net actuarial (gain) loss(1)		(4)		8		9		(1,326)		(765)		(548)
Net periodic benefit cost (credit)	$	12	$	15	$	13	$	(649)	$	(168)	$	71

(1) The Company amortizes actuarial gains and losses over the average remaining active service period of the plan participants and does not use a corridor approach.

Pre-tax amounts included in accumulated other comprehensive loss that have not yet been recognized in net periodic benefit cost

	Supplemental				Postretirement
	Benefit Plan				Health Benefit Plan
	2023		2022		2023		2022
Unrecognized net actuarial gain	$	(9)	$	(18)	$	(6,806)	$	(9,269)

Weighted-average assumptions used to determine benefit obligations and net periodic benefit cost for nonunion defined benefit plans

	Supplemental				Postretirement
	Benefit Plan				Health Benefit Plan
	2023		2022		2023		2022
Discount rate	4.3	%	4.6	%	4.8	%	5.0	%

	Supplemental						Postretirement
	Benefit Plan						Health Benefit Plan
	2023		2022		2021		2023		2022		2021
Discount rate	4.6	%	1.8	%	1.1	%	5.0	%	2.7	%	2.3	%

Schedule of the assumed health care cost trend rates for the postretirement health benefit plan

	2023		2022
Health care cost trend rate assumed for next year(1)	7.0	%	7.0	%
Rate to which the cost trend rate is assumed to decline	4.5	%	4.5	%
Year that the rate reaches the cost trend assumed rate	2035		2034

(1) At each December 31 measurement date, health care cost rates for the following year are based on known premiums for the fully insured postretirement health benefit plan. Therefore, the first year of assumed health care cost trend rates presented as of December 31, 2023 and 2022 are for 2025 and 2024, respectively.

Schedule of estimated future benefit payments for nonunion defined benefit plans

	Supplemental		Postretirement
	Benefit		Health
	Plan		Benefit Plan
2024	$	—	$	707
2025	$	—	$	744
2026	$	—	$	747
2027	$	—	$	754
2028	$	424	$	761
2029-2033	$	—	$	3,836

Schedule of multiemployer pension funds and key participation information

		Pension		FIP/RP
		Protection Act		Status	Contributions(d)
	EIN/Pension	Zone Status(b)		Pending/	(in thousands)						Surcharge
Legal Name of Plan	Plan Number(a)	2023	2022	Implemented(c)	2023		2022		2021		Imposed(e)
Central States, Southeast and Southwest Areas Pension Plan(1)(2)	36-6044243	Critical	Critical and Declining	Implemented(3)	$	77,708	$	75,306	$	71,045	No
Western Conference of Teamsters Pension Plan(4)	91-6145047	Green	Green	No		29,540		28,051		25,861	No
Central Pennsylvania Teamsters Defined Benefit Plan(1)(4)	23-6262789	Green	Green	No		15,540		14,421		13,931	No
I. B. of T. Union Local No. 710 Pension Fund(5)(6)	36-2377656	Green(7)	Green(7)	No		10,676		9,838		9,553	No
New England Teamsters Pension Fund(8)(9)	04-6372430	Critical and Declining(10)	Critical and Declining(10)	Implemented(11)		4,636		4,449		4,357	No
All other plans in the aggregate						24,384		22,493		22,146
Total multiemployer pension contributions paid(12)					$	162,484	$	154,558	$	146,893

Table Heading Definitions

(a) The “EIN/Pension Plan Number” column provides the Federal Employer Identification Number (“EIN”) and the three-digit plan number, if applicable.

(b) Unless otherwise noted, the most recent PPA zone status available in 2023 and 2022 is for the plan’s year-end status at December 31, 2022 and 2021, respectively, and prior to financial assistance from the Pension Relief Act. The zone status is based on information received from the plan and was certified by the plan’s actuary. Green zone funds are those that are in neither endangered, critical, or critical and declining status and generally have a funded percentage of at least 80%.

(c) The “FIP/RP Status Pending/Implemented” column indicates if a funding improvement plan (“FIP”) or a rehabilitation plan (“RP”), if applicable, is pending or has been implemented.

(d) Amounts reflect contributions made in the respective year and differ from amounts expensed during the year.

(e) The surcharge column indicates if a surcharge was paid by ABF Freight to the plan.

Table Footnotes

(1) ABF Freight System, Inc. was listed by the plan as providing more than 5% of the total contributions to the plan for the plan years ended December 31, 2022 and 2021.

(2) Information for this fund was obtained from the 2022 annual funding notice, other notices received from the plan such as the 2023 notice of critical status, and the Form 5500 filed for the plan years ended December 31, 2022 and 2021.

(3) Adopted a rehabilitation plan effective March 25, 2008 as updated. Utilized amortization extension granted by the IRS effective December 31, 2003.

(4) Information for this fund was obtained from the annual funding notice, other notices received from the plan, and the Form 5500 filed for the plan years ended December 31, 2022 and 2021.

(5) The Company was listed by the plan as providing more than 5% of the total contributions to the plan for the plan year ended January 31, 2023.

(6) Information for this fund was obtained from the annual funding notice, other notices received from the plan, and the Form 5500 filed for the plan years ended January 31, 2023 and 2022.

(7) PPA zone status relates to plan years February 1, 2022 – January 31, 2023 and February 1, 2021 – January 31, 2022.

(8) Contributions include $1.6 million each year for 2023, 2022, and 2021, related to the multiemployer pension fund withdrawal liability. ABF Freight’s multiemployer pension plan obligation with the New England Teamsters and Trucking Industry Pension Fund was restructured under a transition agreement effective on August 1, 2018, which triggered a withdrawal liability settlement to satisfy ABF Freight’s existing potential withdrawal liability obligation to the fund. ABF Freight recognized a one-time charge of $37.9 million (pre-tax) to record the withdrawal liability in second quarter 2018; partially settled the withdrawal liability through the initial lump sum cash payment of $15.1 million made in third quarter 2018; and will settle the remainder with monthly payments over a remaining period of 18 years.

(9) Information for this fund was obtained from the annual funding notice, other notices received from the plan, and the Form 5500 filed for the plan years ended September 30, 2022 and 2021.

(10) PPA zone status relates to plan years October 1, 2022 – September 30, 2023 and October 1, 2021 – September 30, 2022.

(11) Adopted a rehabilitation plan effective January 1, 2009. The plan has been subsequently reviewed and restated effective January 1, 2023.

(12) Contribution levels can be impacted by several factors such as changes in business levels and the related time worked by contractual employees, contractual rate increases for pension benefits, and the specific funding structure, which differs among funds. The current and prior collective bargaining agreements and the related supplemental agreements provided for contributions to multiemployer pension plans to be frozen at the current rates for each fund, although certain funds have imposed contribution increases under their rehabilitation or funding improvement plans. The year-over-year changes in multiemployer pension plan contributions presented above were influenced by changes in Asset-Based shipment levels.