XML 62 R45.htm IDEA: XBRL DOCUMENT v3.25.4
Retirement Benefits (Tables)
 12 Months Ended
Dec. 28, 2025
Retirement Benefits [Abstract]  
Schedule of Defined Benefit Plans
The components of pension and other postretirement benefit expense for the Company’s defined benefit plans included the following:
 Pension BenefitsOther Postretirement Benefits
Fiscal Year
(In millions)202520242023202520242023
Service cost - benefits earned during the year$5.3 $5.8 $6.0 $0.4 $0.5 $0.6 
Interest cost on benefits earned in prior years17.4 16.4 79.7 9.9 10.2 10.9 
Expected return on plan assets(15.9)(16.4)(84.8)— — — 
Amortization of prior service cost (credit)0.4 0.3 0.3 (0.9)(0.8)(0.9)
Amortization of net actuarial loss— — — 5.1 5.2 6.0 
Recognized actuarial loss (gain) - mark to market18.6 14.1 26.8 — — — 
Settlement loss— — 41.7 — — — 
Total retirement benefit expense (income)$25.8 $20.2 $69.7 $14.5 $15.1 $16.6 
Schedule of Develop the Components Defined Benefit Pension Expense and Other Postretirement Benefit Expense
Actuarial assumptions used to develop the components of defined benefit pension expense and other postretirement benefit expense were as follows:
 Pension BenefitsOther Postretirement Benefits
Fiscal Year
 202520242023202520242023
Discount rate (a)5.85 %5.60 %
5.55% - 6.40%
5.60 %5.40 %5.45 %
Rate of increase in future compensation levels5.00 %3.00 %3.00 %— %— %— %
Weighted average expected long-term rate of return on assets (a)5.80 %5.80 %
5.80% - 6.57%
— %— %— %
(a) Pension expense for fiscal year 2023 was initially measured at a 5.55% discount rate and 6.57% weighted average expected long-term rate of return on assets. The U.S. qualified pension plans were remeasured using a 6.40% weighted average discount rate and 5.80% weighted average expected long-term rate of return on assets as of October 17, 2023, following the annuity buyout of retirees.
Schedule of Valuation of Defined Benefit Pension Expense and Other Postretirement Benefit Expense
Actuarial assumptions used for the valuation of defined benefit pension and other postretirement benefit obligations at the end of the respective periods were as follows:
 Pension BenefitsOther Postretirement Benefits
Fiscal Year
 2025202420252024
Discount rate5.90 %5.85 %5.30 %5.60 %
Rate of increase in future compensation levels
4.00% - 10.00%
3.00% - 5.00%
— — 
Schedule of Funded Status for the Company’s Defined Benefit Pension and Other Postretirement Benefit Plans
A reconciliation of the funded status for the Company’s defined benefit pension and other postretirement benefit plans at December 28, 2025 and December 29, 2024 was as follows:
 Pension BenefitsOther Postretirement Benefits
Fiscal Year
(In millions)2025202420252024
Change in benefit obligations:
Benefit obligation at beginning of fiscal year$305.6 $298.4 $189.2 $201.6 
Service cost5.3 5.8 0.4 0.5 
Interest cost17.4 16.4 9.9 10.2 
Benefits paid(12.8)(3.5)(24.1)(25.4)
Net actuarial (gains) losses – discount rate change(2.0)(9.7)3.5 (2.5)
                  – other19.5 (1.8)3.3 4.8 
Benefit obligation at end of fiscal year$333.0 $305.6 $182.2 $189.2 
Schedule of Actuarial Effects of Changes in Discount Rates
Actuarial effects of changes in discount rates are separately identified in the preceding table.

 Pension BenefitsOther Postretirement Benefits
Fiscal Year
(In millions)2025202420252024
Change in plan assets:
Fair value of plan assets at beginning of fiscal year$279.8 $289.1 $— $— 
Actual returns on plan assets and plan expenses14.8 (9.1)— — 
Employer contributions5.1 3.3 — — 
Benefits paid(12.8)(3.5)— — 
Fair value of plan assets at end of fiscal year$286.9 $279.8 $— $— 
Schedule of Assets (Liabilities)
Assets (liabilities) recognized in the consolidated balance sheets:
Pension BenefitsOther Postretirement Benefits
Fiscal Year
2025202420252024
Noncurrent assets$— $16.6 $— $— 
Current liabilities(4.8)(5.2)(23.7)(24.9)
Noncurrent liabilities(41.4)(37.2)(158.5)(164.3)
Total amount recognized$(46.2)$(25.8)$(182.2)$(189.2)
Schedule of Changes to Accumulated Other Comprehensive Loss
Changes to accumulated other comprehensive loss related to pension and other postretirement benefit plans in fiscal years 2025 and 2024 were as follows:
 Pension BenefitsOther Postretirement Benefits
Fiscal Year
(In millions)2025202420252024
Beginning of year accumulated other comprehensive loss$(7.1)$(7.4)$(52.3)$(54.5)
Amortization of net actuarial loss— — 5.1 5.2 
Amortization of prior service cost (credit)0.4 0.3 (0.9)(0.8)
Settlement loss — — — — 
Remeasurements— — (6.7)(2.2)
End of year accumulated other comprehensive loss$(6.7)$(7.1)$(54.8)$(52.3)
Net change in accumulated other comprehensive loss$0.4 $0.3 $(2.5)$2.2 
Schedule of Amounts Included in Accumulated Other Comprehensive Loss
Amounts included in accumulated other comprehensive loss at December 28, 2025 and December 29, 2024 were as follows:
 Pension BenefitsOther Postretirement Benefits
Fiscal Year
(In millions)2025202420252024
Prior service (cost) credit$(6.7)$(7.1)$— $0.8 
Net actuarial loss— — (54.8)(53.1)
Accumulated other comprehensive loss(6.7)(7.1)(54.8)(52.3)
Deferred tax effect1.8 1.9 27.5 27.0 
Accumulated other comprehensive loss, net of tax$(4.9)$(5.2)$(27.3)$(25.3)
Schedule of Amounts in Accumulated Other Comprehensive Loss that are Expected to be Recognized as Components of Net Periodic Benefit Cost Amounts in accumulated other comprehensive loss that are expected to be recognized as components of net periodic benefit cost in fiscal year 2026 are:
(In millions)Pension
Benefits		Other
Postretirement
Benefits		Total
Amortization of prior service cost (credit)$0.4 $(0.3)$0.1 
Amortization of net actuarial loss— 5.2 5.2 
Amortization of accumulated other comprehensive loss$0.4 $4.9 $5.3 
Schedule of Additional Information For Pension Plans Additional information for pension plans with accumulated benefit obligations and projected benefit obligations in excess of plan assets:
 Pension Benefits
Fiscal Year
(In millions)20252024
Projected benefit obligation$39.0 $42.4 
Accumulated benefit obligation$39.0 $42.4 
Fair value of plan assets$— $— 
Schedule of Expected Benefit Payments
The following table summarizes expected benefit payments from the Company’s various pension and other postretirement defined benefit plans through fiscal year 2035, and also includes estimated Medicare Part D subsidies projected to be received during this period based on currently available information. Pension benefit payments for the U.S. qualified defined benefit pension plan are made from pension plan assets.
(In millions)
Fiscal YearPension
Benefits		Other
Postretirement
Benefits		Medicare Part
D Subsidy
2026$16.4 $23.7 $— 
202717.8 22.3 — 
202818.7 20.8 — 
202919.3 19.4 — 
203020.2 17.8 — 
2031-2035113.1 69.0 — 
Schedule of Pension Plan Assets are Determined Using Net Asset Value (NAV)
The fair values of the Company’s pension plan assets are determined using net asset value (NAV) as a practical expedient, or by information categorized in the fair value hierarchy level based on the inputs used to determine fair value, as further discussed in Note 13. The fair values at December 28, 2025 were as follows:
(In millions) Quoted Prices in
Active Markets for
Identical Assets		Significant
Observable Inputs		Significant
Unobservable  Inputs
Asset categoryTotalNAV (Level 1)(Level 2)(Level 3)
Equity securities:
U.S. equities $0.1 $— $0.1 $— $— 
Fixed income and cash equivalents206.2 1.0 205.2 — — 
Private equity68.2 68.2 — — — 
Alternative investments- hedge funds, real estate and other12.4 12.4 — — — 
Total assets$286.9 $81.6 $205.3 $— $— 
The fair values of the Company’s pension plan assets at December 29, 2024 were as follows:
(In millions) Quoted Prices in
Active Markets for
Identical Assets		Significant
Observable Inputs		Significant
Unobservable  Inputs
Asset categoryTotalNAV (Level 1)(Level 2)(Level 3)
Equity securities:
U.S. equities $0.1 $— $0.1 $— $— 
Fixed income and cash equivalents 199.2 5.3 193.9 — — 
Private equity60.8 60.8 — — — 
Alternative investments- hedge funds, real estate and other19.7 19.7 — — — 
Total assets$279.8 $85.8 $194.0 $— $— 
Schedule of Target Asset Allocations For ATI Pension Plan
The target asset allocations for ATI Pension Plan for fiscal year 2026, by major investment category, are:
Asset categoryTarget asset allocation range
Equities
0% - 20%
Fixed income and cash equivalents
50% - 100%
Private equity and other
0% - 40%
Schedule of Participation In Multiemployer Plans
The Company’s participation in multiemployer plans for the fiscal years ended December 28, 2025, December 29, 2024 and December 31, 2023 is reported in the following table.
  Pension
Protection Act
Zone Status (1)		FIP / RP Status
Pending /
Implemented (2)		in millions Expiration Dates
of Collective
Bargaining
Agreements
 EIN / Pension
Plan Number		Company ContributionsSurcharge
Imposed (3)
Fiscal YearFiscal Year
Pension Fund20252024202520242023
Steelworkers Western Independent Shops Pension Plan90-0169564
/ 001		GreenGreenN/A$1.3 $1.1 $0.7 No2/28/2031
Boilermakers-Blacksmiths National Pension Trust48-6168020
/ 001		RedRedYes3.1 2.7 2.6 No9/30/2026
IAM National Pension Fund51-6031295
/ 002		RedRedYes2.3 2.1 1.9 YesVarious between 2026-2029 (4)
Total contributions$6.7 $5.9 $5.2 
(1)The most recent Pension Protection Act Zone Status is based on information provided to ATI and other participating employers by each plan, as certified by the plan’s actuary. A plan in the “deep red” zone had been determined to be in “critical and declining status”, based on criteria established by the Internal Revenue Code (Code), and is in critical status (as defined by the “red” zone) and is projected to become insolvent (run out of money to pay benefits) within 15 years (or within 20 years if a special rule applies). A plan in the “red” zone had been determined to be in “critical status”, based on criteria established by the Code, and is generally less than 65% funded. A plan in the “yellow” zone has been determined to be in “endangered status”, based on criteria established under the Code, and is generally less than 80% funded. A plan in the “green” zone has been determined to be neither in “critical status” nor in “endangered status”, and is generally at least 80% funded. Additionally, a plan may voluntarily place itself into a rehabilitation plan.
In April 2019, the Company received notification from the IAM National Pension Fund (IAM Fund) that its’ actuary certified the IAM Fund as “endangered status” for the plan year beginning January 1, 2019, and that the IAM Fund was voluntarily placing itself in “red” zone status and implementing a rehabilitation plan. Annually in April of each year from 2020 through 2025, the Company received notification from the IAM Fund that it was certified by its actuary as being in “red” zone status for each of these plan years from January 1, 2020 through December 31, 2025. A contribution surcharge was imposed as of June 1, 2019 in addition to the contribution rate specified in the applicable collective bargaining agreements. The contribution surcharge remains in effect, and ends when an employer begins contributing under a collective bargaining agreement that includes terms consistent with the rehabilitation plan.
In April 2019, the Company received notifications from the Boilermakers-Blacksmiths National Pension Trust (Blacksmiths Trust) that it was certified by its actuary as being in “red” zone status for the plan year beginning January
1, 2019. A rehabilitation plan was adopted for the Blacksmiths Trust, and the Company and the Blacksmiths union agreed to adopt the rehabilitation plan in 2019 prior to a contribution surcharge being imposed. In April 2020 and 2021, the funding status improved for the Blacksmiths Trust as it was certified by its actuary as being in the “yellow” zone for the plan years beginning January 1, 2020 and 2021. In April 2022, the funding status further improved to being in the “green” zone for the plan year beginning January 1, 2022. In April 2023, the Blacksmiths Trust was certified by its actuary as being in “red” zone status for the plan years beginning January 1, 2023, and in April 2024 and April 2025, the Blacksmiths Trust was certified by its actuary as being in “red” zone status for the plan years ending December 31, 2023 and December 31, 2024, respectively. A rehabilitation plan has been adopted for the Blacksmiths Trust, and the Company and the Blacksmiths union agreed to adopt the rehabilitation plan in 2023 prior to a contribution surcharge being imposed.
(2)The “FIP / RP Status Pending / Implemented” column indicates whether a Funding Improvement Plan, as required under the Code by plans in the “yellow” zone, or a Rehabilitation Plan, as required under the Code to be adopted by plans in the “red” or “deep red” zones, is pending or has been implemented as of the end of the plan year that ended in 2025.
(3)The “Surcharge Imposed” column indicates whether ATI’s contribution rate for 2025 included an amount in addition to the contribution rate specified in the applicable collective bargaining agreement, as imposed by a plan in “critical status” or “critical and declining status”, in accordance with the requirements of the Code.
(4)The Company is party to six separate bargaining agreements that require contributions to this plan. Expiration dates of these collective bargaining agreements range between April 26, 2026 and March 31, 2029.