401(k) · DOL Form 5500 · 2023

Amentum Services, Inc. 401(k) Plan

Data updated 2026-08-25

$2.2B
Total assets Very large vs avg
22,820
Participants Very large workforce
99th
Percentile by assets National rank
$96,147
Avg per participant Below avg balance/head
PlainRetire home → About this data RSS: change history

Official DOL plan name: Amentum 401(k) Retirement Plan · Sponsored by Amentum Services, Inc. · Virginia · Professional & Technical Services

$2.2B in assets, 22,820 participants

Amentum Services, Inc.'s Amentum 401(k) Retirement Plan reported $2.2B in total assets and 22,820 participants in its 2023 DOL Form 5500 filing, ranking in the 99th percentile by assets among filed plans. Figures are as reported by the plan sponsor to the Department of Labor, not audited or endorsed by PlainRetire.

  • #20,250 in Professional & Technical Services (20,321 peers)

Coverage in Virginia

Amentum 401(k) Retirement Plan covers 22,820 participants in Virginia, 29x the typical Virginia plan (state average ~782 per filing). Assets: $2.2B.

#20,250
in Professional & Technical Services (20,321 peers)
+18.6%
assets growth YoY
22×
vs typical plan assets (national mean)

Amentum 401(k) Retirement Plan's outsized position by total assets

Amentum 401(k) Retirement Plan vs every filed plan by assets

End-of-year total assets · plan year 2023 · DOL Form 5500

$2,194,066,026 Top 1% higher than 99% of 127,068 filed plans

This plan $0 $2,050,000,000 every filed plan with reported assets, bucketed by value

Dashed line + filled bar = this entry, among filed plans.

Source U.S. Department of Labor Form 5500 filings (EBSA) · plan year 2023

Amentum 401(k) Retirement Plan's mega-plan peer group by participant headcount

Plan-year 2023 Form 5500 filings with a reported participant count, partitioned by headcount band, not by assets. Amentum 401(k) Retirement Plan is a mega filing (22,820 participants), the rightmost band on the breakdown.

What changed between DOL Form 5500 filings

plan year 2022 → plan year 2023

  • Amentum 401(k) Retirement Plan reported net income rose from -$343M in the plan year 2022 filing to $343M in the plan year 2023 filing.
  • Amentum 401(k) Retirement Plan reported participants rose from 15,670 in the plan year 2022 filing to 22,820 in the plan year 2023 filing.
  • Amentum 401(k) Retirement Plan end-of-year assets rose from $1.8B in the plan year 2022 filing to $2.2B in the plan year 2023 filing.

See the national 2022→2023 release diff →

Form 5500 schedule snapshot

Filing strip 271628265 · Amentum Services, Inc. PY 2023 · 401(k)

Amentum 401(k) Retirement Plan · $2.2B · 22,820 · 99th

  • EIN $2.2B
  • RANK 22,820
  • PHOTO 99th
  • IND 401(k)
  • EOY near Precision Castparts Corp. 401(k) Retirement Savings Plan
  • 5500 ind #20250

Stamps derive from this plan's Form 5500 line items (assets, participants, type, EIN, cohort placement) - not a quality rating of the sponsor. Read with Professional & Technical Services retirement plans → · Plans in Virginia →

Amentum 401(k) Retirement Plan in the asset neighbourhood

The Investment-Incentive Plan for John Hancock EmployeesThe Investment-Incentive Pla…$2.2BPentegra Defined Contribution Plan for Financial InstitutionsPentegra Defined Contributio…$2.2BAmentum 401(k) Retirement PlanAmentum 401(k) Retirement Pl…$2.2BPrecision Castparts Corp. 401(k) Retirement Savings PlanPrecision Castparts Corp. 40…$2.2BFirst-Citizens Bank & Trust Company 401(k) PlanFirst-Citizens Bank & Trust …$2.2B
End-of-year total assets ($B) among Amentum 401(k) Retirement Plan and nearest nationwide 401(k) peers. Source: DOL Form 5500 plan year 2023.

Virginia filing particulars

Total Assets (Beginning of Year)$1.8B
Net Assets (End of Year)$2.2B
Net Income$343M
Employer EIN271628265
Plan Effective Date2011-01-01
Filing StatusFILING RECEIVED

Sponsor Plan History (Amentum Services, Inc.)

Sponsor-wide plan assets over time

All Amentum Services, Inc. plans reported in each filing year

Latest sponsor-wide plan assets
$2.5B 34.67348079974608% vs 2022
2024 filing year
$1.6B$1.8B$2B$2.2B$2.4B$2.6B 202220232024 $1.85B $2.49B ▲ +34.6%
Year Plans Participants Total Assets
2022 1 15,670 $1.8B
2023 1 22,820 $2.2B
2024 1 31,017 $2.5B

Nearby 401(k) Plans in Virginia

Peer 401(k) plans, same state, same plan type, ranked by total assets.

Amentum 401(k) Retirement Plan vs. nearby 401(k) plans in Virginia, assets vs. participants Scatter plot of 6 data points. 020000400006000080000100000120000 010203040 Total assets ($B) Participants Amentum 401(k) Retirement Plan, Total assets ($B): 2.194066026 · Participants: 22820Amentum 401(k) Retirement PlanNorthrop Grumman Savings Plan, Total assets ($B): 36.173098625 · Participants: 97987Northrop Grumman Savings Plan401(k) Pension Plan, Total assets ($B): 14.97867624 · Participants: 62467401(k) Pension PlanGeneral Dynamics Corporation 401(k) Plan 6.0, Total assets ($B): 11.167449098 · Participants: 48860General Dynamics Corporation 401(k) Plan 6.0Leidos, Inc. Retirement Plan, Total assets ($B): 10.583898778 · Participants: 27043Leidos, Inc. Retirement PlanBae Systems Employees' Savings and Investment Plan, Total assets ($B): 9.406287325 · Participants: 31681Bae Systems Employees' Savings and Investment Plan
Amentum 401(k) Retirement Plan vs. nearby 401(k) plans in Virginia, assets vs. participants
Compare Amentum 401(k) Retirement Plan side-by-side with 3 peers →

Scale composition for Amentum 401(k) Retirement Plan

Amentum 401(k) Retirement Plan reports $2.2B in end-of-year assets across 22,820 participants (0.018% of the $12.3T held by all Form 5500 filers in the national rollup , and 0.024% of 93,925,755 covered participants) - about $96,147 per participant (70% of the national average assets-per-participant) . Net income for plan year 2023 was $343M.

This plan identity (EIN 271628265, plan #001) has 3 Form 5500 filings on file from 2022 to 2024 , with end-of-year assets moving from $1.8B to $2.5B (+34.7%) while covered participants moved from 15,670 to 31,017 . Single-year sparse filers cannot show that trail.

Plan year Participants EOY assets Filing
2022 15,670 $1.8B Open filing
2023 22,820 $2.2B This page
2024 · index core 31,017 $2.5B Open filing

The same sponsor also keeps 1 other index-core plan on PlainRetire:

Amentum 401(k) Retirement Plan's out-of-state 401(k) peers by assets and headcount

Outside Virginia, the nearest 401(k) by assets is Precision Castparts Corp. 401(k) Retirement Savings Plan in OR ($2.2B); by covered participants it is Conduent Savings Plan in NJ (22,816 participants). Same-state nearby plans are listed separately above.

Similar participant headcount

Nearest other-state filings by covered participants (22,820 participants); asset peers above are excluded.

DOL Form 5500 plan year 2023. Asset totals can differ widely at the same headcount; neither axis is a quality rating.

Frequently Asked Questions

How did Amentum 401(k) Retirement Plan assets move in 2023? ▼
Amentum 401(k) Retirement Plan grew sharply - up 18.6% during 2023, from $1.8B to $2.2B. Reported net income was $343M.
How have Amentum Services, Inc. plan assets changed over time? ▼
Across 3 plan years on file (2022-2024), Amentum Services, Inc.'s sponsor-wide assets grew 34.7%, from $1.8B to $2.5B.
Where does Amentum 401(k) Retirement Plan rank by assets among Form 5500 filers? ▼
Amentum 401(k) Retirement Plan ranks in the 99th percentile by end-of-year assets among 127,072 plans that reported assets for plan year 2023 (among the largest 1% of all filed plans).
Which 401(k) plans are similar in size to Amentum 401(k) Retirement Plan? ▼
Among 401(k) plans in other states, the closest by assets is Precision Castparts Corp. 401(k) Retirement Savings Plan in OR ($2.2B, 16,687 participants).
Which 401(k) plans cover a similar participant headcount to Amentum 401(k) Retirement Plan? ▼
Among 401(k) plans in other states, the closest by covered participants is Conduent Savings Plan in NJ (22,816 participants, $1.0B in assets).

Source: U.S. Department of Labor, Employee Benefits Security Administration (EBSA), Form 5500 public disclosure dataset. Plan year 2023.

Source: DOL EFAST2 filing system (efast.dol.gov) - original filing retrieval by EIN 271628265.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from U.S. Department of Labor Form 5500 filings (EBSA). See our methodology for details.