v3.26.1
Pension and Other Postretirement Benefit Costs
 6 Months Ended
Jun. 30, 2026
Pension and Other Postretirement Benefits Cost (Reversal of Cost) [Abstract]  
Pension and Other Postretirement Benefit Costs PENSION AND OTHER POSTRETIREMENT BENEFIT COSTS
NW Natural maintains a qualified non-contributory defined benefit pension plan (Pension Plan), non-qualified supplemental pension plans for eligible executive officers and other key employees, and other postretirement employee benefit plans. NW Natural also has a qualified defined contribution plan (Retirement K Savings Plan) for all eligible employees. The Pension Plan and Retirement K Savings Plan have plan assets, which are held in qualified trusts to fund retirement benefits.
The service cost component of net periodic benefit cost for NW Natural pension and other postretirement benefit plans is recognized in operations and maintenance expense in the consolidated statements of comprehensive income. The other non-service cost components are recognized in other income (expense), net in the consolidated statements of comprehensive income.

The following table provides the components of net periodic benefit cost (credit) for the pension and other postretirement benefit plans:
Three Months Ended June 30,Six Months Ended June 30,
Pension BenefitsOther Postretirement
Benefits		Pension BenefitsOther
Postretirement Benefits
In thousands20262025202620252026202520262025
Service cost$854 $886 $27 $28 $1,709 $1,771 $53 $55 
Interest cost5,166 5,410 282 289 10,333 10,820 564 577 
Expected return on plan assets(5,590)(5,433)— — (11,181)(10,866)— — 
Amortization of net actuarial loss2,296 2,445 62 21 4,591 4,889 125 41 
Net periodic benefit cost 2,726 3,308 371 338 5,452 6,614 742 673 
Amount allocated to construction(417)(429)(11)(11)(822)(863)(22)(22)
Net periodic benefit cost charged to expense2,309 2,879 360 327 4,630 5,751 720 651 
Amortization of regulatory balancing account1,281 1,281 — — 4,082 4,082 — — 
Net amount charged to expense$3,590 $4,160 $360 $327 $8,712 $9,833 $720 $651 

Net periodic benefit costs are reduced by amounts capitalized to NW Natural plant. In addition, net periodic benefit costs were recorded to a regulatory balancing account as approved by the OPUC and amortized accordingly.

The following table presents amounts recognized in accumulated other comprehensive loss (AOCL) and the changes in AOCL related to non-qualified employee benefit plans:
Three Months Ended June 30,Six Months Ended June 30,
In thousands2026202520262025
Beginning balance$(4,614)$(6,877)$(4,705)$(7,052)
Amounts reclassified from AOCL:
Amortization of actuarial losses124 199 248 399 
Total reclassifications before tax124 199 248 399 
Tax benefit(33)(25)(66)(50)
Total reclassifications for the period91 174 182 349 
Ending balance$(4,523)$(6,703)$(4,523)$(6,703)

Employer Contributions to Company-Sponsored Defined Benefit Pension Plans
NW Natural made $6.5 million of cash contributions to its qualified defined benefit pension plans during the six months ended June 30, 2026 and $5.5 million cash contributions during the six months ended June 30, 2025.

Defined Contribution Plan
NW Natural's Retirement K Savings Plan is a qualified defined contribution plan under Internal Revenue Code Sections 401(a) and 401(k). NW Natural contributions totaled $7.2 million and $6.9 million for the six months ended June 30, 2026 and 2025, respectively.

See Note 10 in the 2025 Form 10-K for more information concerning these retirement and other postretirement benefit plans.