Defined Benefit and Other Postretirement Benefits

12 Months Ended

Dec. 31, 2024

Retirement Benefits [Abstract]

Defined Benefit and Other Postretirement Benefits

Note 15 – Defined Benefit and Other Postretirement Benefits

Qualified Pension Plan

Trustmark maintains a noncontributory tax-qualified defined benefit pension plan titled the Trustmark Corporation Pension Plan for Certain Employees of Acquired Financial Institutions (the Continuing Plan) to satisfy commitments made by Trustmark to associates covered through plans obtained in acquisitions.

The following tables present information regarding the benefit obligation, plan assets, funded status, amounts recognized in accumulated other comprehensive loss, net periodic benefit cost and other statistical disclosures for the Continuing Plan for the periods presented ($ in thousands):

	December 31,
	2024			2023
Change in benefit obligation:
Benefit obligation, beginning of year	$	5,923		$	6,907
Service cost		40			52
Interest cost		246			292
Actuarial (gain) loss		(214	)		164
Benefits paid		(464	)		(1,492	)
Benefit obligation, end of year	$	5,531		$	5,923
Change in plan assets:
Fair value of plan assets, beginning of year	$	2,403		$	2,907
Actual return on plan assets		233			237
Employer contributions		513			751
Benefit payments		(464	)		(1,492	)
Fair value of plan assets, end of year	$	2,685		$	2,403
Funded status at end of year - net liability	$	(2,846	)	$	(3,520	)
Amounts recognized in accumulated other comprehensive loss:
Net (gain) loss - amount recognized	$	(601	)	$	(262	)
Actuarial (gain) loss included in benefit obligation:
Change in discount rate	$	(344	)	$	124
Change in mortality table		—			(38	)
Other		130			78
Actuarial (gain) loss	$	(214	)	$	164

	Years Ended December 31,
	2024			2023			2022
Net periodic benefit cost:
Service cost	$	40		$	52		$	115
Interest cost		246			292			192
Expected return on plan assets		(96	)		(107	)		(121	)
Recognized net (gain) loss due to lump sum settlements		(13	)		25			—
Recognized net actuarial loss		—			—			224
Net periodic benefit cost	$	177		$	262		$	410
Other changes in plan assets and benefit obligation recognized in other    comprehensive income (loss), before taxes:
Net loss - Total recognized in other comprehensive income (loss)	$	(339	)	$	9		$	(1,699	)
Total recognized in net periodic benefit cost and other comprehensive    income (loss)	$	(162	)	$	271		$	(1,289	)
Weighted-average assumptions as of end of year:
Discount rate for benefit obligation		5.30	%		4.67	%		4.88	%
Discount rate for net periodic benefit cost		4.67	%		4.88	%		2.41	%
Expected long-term return on plan assets		5.00	%		5.00	%		5.00	%

Plan Assets

The weighted-average asset allocations by asset category are presented below for the Continuing Plan at December 31, 2024 and 2023.

	December 31,
	2024			2023
Money market fund		2.0	%		27.0	%
Exchange traded funds:
Equity securities		33.0	%		36.0	%
Fixed income		59.0	%		28.0	%
International		6.0	%		9.0	%
Total		100.0	%		100.0	%

The strategic objective of the investments of the assets in the Continuing Plan aims to provide both income and potential capital appreciation. The allocation is managed on a total return basis with the average participant age in mind. It is well suited for moderately conservative investors seeking an ample level of income while also participating in equity markets. This investment mix is designed to take advantage of rising stock markets while cushioning the effects of stock market downturns. The portfolio is typically balanced between equity and fixed income. The equity exposure has the potential to earn a return greater than inflation while the fixed income exposure may reduce the risk and volatility of the portfolio to which the equity mutual funds contribute.

Fair Value Measurements

At this time, Trustmark presents no fair values that are derived through internal modeling. Should positions requiring fair valuation arise that are not relevant to existing methodologies, Trustmark will make every reasonable effort to obtain market participant assumptions, or independent evaluation.

The following tables set forth by level, within the fair value hierarchy, the Continuing Plan’s assets measured at fair value at December 31, 2024 and 2023 ($ in thousands):

	December 31, 2024
	Total		Level 1		Level 2		Level 3
Money market fund	$	55	$	55	$	—	$	—
Exchange traded funds:
Equity securities		874		874		—		—
Fixed income		1,600		1,600		—		—
International		156		156		—		—
Total assets at fair value	$	2,685	$	2,685	$	—	$	—

	December 31, 2023
	Total		Level 1		Level 2		Level 3
Money market fund	$	643	$	643	$	—	$	—
Exchange traded funds:
Equity securities		861		861		—		—
Fixed income		690		690		—		—
International		209		209		—		—
Total assets at fair value	$	2,403	$	2,403	$	—	$	—

There have been no changes in the methodologies used in estimating the fair value of plan assets at December 31, 2024. The money market fund approximates fair value due to its immediate maturity.

The preceding methods described may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. Furthermore, although Trustmark believes their valuation methods are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different fair value measurement at the reporting date.

Contributions

The range of potential contributions to the Continuing Plan is determined annually by the Continuing Plan’s actuary in accordance with applicable IRS rules and regulations. Trustmark’s policy is to fund amounts that are sufficient to satisfy the annual minimum funding requirements and do not exceed the maximum that is deductible for federal income tax purposes. The actual amount of the contribution

is determined annually based on the Continuing Plan’s funded status and return on plan assets as of the measurement date, which is December 31. For the plan year ending December 31, 2024, Trustmark’s minimum required contribution to the Continuing Plan was $127 thousand and Trustmark contributed $290 thousand. For the plan year ending December 31, 2025, Trustmark’s minimum required contribution to the Continuing Plan is expected to be $109 thousand. Management and the Board of Directors of Trustmark will monitor the Continuing Plan throughout 2025 to determine any additional funding requirements by the plan’s measurement date.

Estimated Future Benefit Payments and Other Disclosures

The following table presents the expected benefit payments, which reflect expected future service, for the Continuing Plan ($ in thousands):

Year	Amount
2025	$	693
2026		762
2027		961
2028		535
2029		414
2030 - 2034		1,575

Amounts in accumulated other comprehensive income (loss) expected to be recognized as components of net periodic benefit cost during 2025 include a gain of $7 thousand.

Supplemental Retirement Plans

Trustmark maintains a nonqualified supplemental retirement plan covering key executive officers and senior officers as well as directors who have elected to defer fees. The plan provides for retirement and/or death benefits based on a participant’s covered salary or deferred fees. Although plan benefits may be paid from Trustmark’s general assets, Trustmark has purchased life insurance contracts on the participants covered under the plan, which may be used to fund future benefit payments under the plan. The annual measurement date for the plan is December 31. As a result of mergers prior to 2014, Trustmark became the administrator of nonqualified supplemental retirement plans, for which the plan benefits were frozen prior to the merger date.

The following tables present information regarding the benefit obligation, plan assets, funded status, amounts recognized in accumulated other comprehensive loss, net periodic benefit cost and other statistical disclosures for Trustmark’s nonqualified supplemental retirement plans for the periods presented ($ in thousands):

	December 31,
	2024			2023
Change in benefit obligation:
Benefit obligation, beginning of year	$	41,619		$	43,201
Service cost		45			69
Interest cost		1,851			2,013
Actuarial (gain) loss		(1,009	)		763
Benefits paid		(4,344	)		(4,427	)
Benefit obligation, end of year	$	38,162		$	41,619
Change in plan assets:
Fair value of plan assets, beginning of year	$	—		$	—
Employer contributions		4,344			4,427
Benefit payments		(4,344	)		(4,427	)
Fair value of plan assets, end of year	$	—		$	—
Funded status at end of year - net liability	$	(38,162	)	$	(41,619	)
Amounts recognized in accumulated other comprehensive loss:
Net loss	$	6,880		$	8,235
Prior service cost		15			126
Amounts recognized	$	6,895		$	8,361
Actuarial (gain) loss included in benefit obligation:
Change in discount rate	$	(1,794	)	$	649
Change in mortality table		—			(308	)
Other		785			422
Actuarial (gain) loss	$	(1,009	)	$	763

	Years Ended December 31,
	2024			2023			2022
Net periodic benefit cost:
Service cost	$	45		$	69		$	71
Interest cost		1,851			2,013			1,278
Amortization of prior service cost		111			111			111
Recognized net actuarial loss		346			284			986
Net periodic benefit cost	$	2,353		$	2,477		$	2,446
Other changes in plan assets and benefit obligation recognized in other    comprehensive income (loss), before taxes:
Net (gain) loss	$	(1,355	)	$	479		$	(10,181	)
Amortization of prior service cost		(111	)		(111	)		(111	)
Total recognized in other comprehensive income (loss)	$	(1,466	)	$	368		$	(10,292	)
Total recognized in net periodic benefit cost and other comprehensive    income (loss)	$	887		$	2,845		$	(7,846	)
Weighted-average assumptions as of end of year:
Discount rate for benefit obligation		5.30	%		4.67	%		4.88	%
Discount rate for net periodic benefit cost		4.67	%		4.88	%		2.41	%

Estimated Supplemental Retirement Plan Payments and Other Disclosures

The following table presents the expected benefits payments for Trustmark’s supplemental retirement plans ($ in thousands):

Year	Amount
2025	$	3,885
2026		3,850
2027		3,673
2028		3,550
2029		3,545
2030 - 2034		15,563

Amounts in accumulated other comprehensive income (loss) expected to be recognized as components of net periodic benefit cost during 2025 include a loss of $261 thousand and prior service cost of $15 thousand.

Other Benefit Plans

Defined Contribution Plan

Trustmark provides associates with a self-directed 401(k) retirement plan that allows associates to contribute a percentage of eligible compensation, within limits provided by the Internal Revenue Code and accompanying regulations, into the plan. Trustmark matches 100% of associate contributions to the plan based on the amount of each participant’s contributions up to a maximum of 6% of eligible compensation, subject to the IRS maximum eligible compensation. Associates are automatically enrolled in the plan at 3% of eligible compensation unless they opt out within 60 days of employment. Associates may become eligible to make elective deferral contributions the first of the month following one month of employment. Eligible associates that elect to participate vest immediately in Trustmark’s matching contributions, as this is a Safe Harbor 401(k) Plan. Trustmark’s contributions to this plan were $10.7 million in 2024, $10.8 million in 2023 and $10.2 million in 2022.