401(k) · DOL Form 5500 · 2023

Diamond Offshore Management Company 401(k) Plan

Data updated 2026-08-25

$356M
Total assets Above avg plan size
1,183
Participants Near avg headcount
97th
Percentile by assets National rank
$300,758
Avg per participant High balance/head
PlainRetire home → About this data RSS: change history

Official DOL plan name: Diamond Offshore 401(k) Plan · Sponsored by Diamond Offshore Management Company · Texas · Mining & Oil Extraction

$356M in assets, 1,183 participants

Diamond Offshore Management Company's Diamond Offshore 401(k) Plan reported $356M in total assets and 1,183 participants in its 2023 DOL Form 5500 filing, ranking in the 97th 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.

  • #757 in Mining & Oil Extraction (811 peers)

Where Diamond Offshore 401(k) Plan sits by assets

Diamond Offshore 401(k) Plan sits in the top 5% of all filed plans by assets, $356M for 1,183 participants (~$300,758/participant), up 11.4% in 2023.

#757
in Mining & Oil Extraction (811 peers)
+11.4%
assets growth YoY
3.6×
vs typical plan assets (national mean)

Diamond Offshore 401(k) Plan's outsized position by total assets

Diamond Offshore 401(k) Plan vs every filed plan by assets

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

$355,796,435 Top 3% higher than 97% 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

Diamond Offshore 401(k) Plan's large-plan peer group by participant headcount

Plan-year 2023 Form 5500 filings with a reported participant count, partitioned by headcount band, not by assets. Diamond Offshore 401(k) Plan lands in the large band (1,183 participants).

What changed between DOL Form 5500 filings

plan year 2022 → plan year 2023

  • Diamond Offshore 401(k) Plan reported net income rose from -$101M in the plan year 2022 filing to $36M in the plan year 2023 filing.
  • Diamond Offshore 401(k) Plan reported participants rose from 1,043 in the plan year 2022 filing to 1,183 in the plan year 2023 filing.
  • Diamond Offshore 401(k) Plan end-of-year assets rose from $319M in the plan year 2022 filing to $356M in the plan year 2023 filing.

See the national 2022→2023 release diff →

Published 5500 schedule card

Filing strip 133560049 · Diamond Offshore Management Company PY 2023 · 401(k)

Diamond Offshore 401(k) Plan · $356M · 1,183 · 97th

  • IND $356M
  • IND 1,183
  • IND 97th
  • IND 401(k)
  • IND near The Safe Harbor 401(k) Plan
  • IND ind #757

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 Mining & Oil Extraction retirement plans → · Plans in Texas →

Diamond Offshore 401(k) Plan in the asset neighbourhood

Proskauer Rose LLP Savings Plan for Staff and PartnersProskauer Rose LLP Savings P…$356MAg US Group Services Inc. Employee Retirement PlanAg US Group Services Inc. Em…$356MDiamond Offshore 401(k) Plan$356MThe Safe Harbor 401(k) Plan$356MBendix Commercial Vehicle Systems LLC Savings PlanBendix Commercial Vehicle Sy…$356M
End-of-year total assets ($M) among Diamond Offshore 401(k) Plan and nearest nationwide 401(k) peers. Source: DOL Form 5500 plan year 2023.

Scale-class filing particulars (2023)

Total Assets (Beginning of Year)$319M
Net Assets (End of Year)$356M
Net Income$36M
Employer EIN133560049
Plan Effective Date1989-07-01
Filing StatusFILING RECEIVED

Sponsor Plan History (Diamond Offshore Management Company)

Sponsor-wide plan assets over time

All Diamond Offshore Management Company plans reported in each filing year

Latest sponsor-wide plan assets
$377M 18.17211394381709% vs 2022
2024 filing year
$300M$320M$340M$360M$380M$400M 202220232024 $319M $377M ▲ +18.2%
Year Plans Participants Total Assets
2022 1 1,043 $319M
2023 1 1,183 $356M
2024 1 1,272 $377M

Nearby 401(k) Plans in Texas

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

Diamond Offshore 401(k) Plan vs. nearby 401(k) plans in Texas, assets vs. participants Scatter plot of 6 data points. -50000050000100000150000 -1001020304050 Total assets ($B) Participants Diamond Offshore 401(k) Plan, Total assets ($B): 0.355796435 · Participants: 1183Diamond Offshore 401(k) PlanAT&T Retirement Savings Plan, Total assets ($B): 40.012012 · Participants: 119854AT&T Retirement Savings PlanExxonmobil Savings Plan, Total assets ($B): 21.917 · Participants: 23477Exxonmobil Savings PlanCaterpillar 401(k) Savings Plan, Total assets ($B): 16.496476432 · Participants: 41679Caterpillar 401(k) Savings PlanAmerican Airlines, Inc. 401(k) Plan, Total assets ($B): 14.680189879 · Participants: 88792American Airlines, Inc. 401(k) PlanDell Inc. 401(k) Plan, Total assets ($B): 13.529835 · Participants: 45686Dell Inc. 401(k) Plan
Diamond Offshore 401(k) Plan vs. nearby 401(k) plans in Texas, assets vs. participants
Compare Diamond Offshore 401(k) Plan side-by-side with 3 peers →

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

Outside Texas, the nearest 401(k) by assets is The Safe Harbor 401(k) Plan in NY ($356M); by covered participants it is The Polyclinic a P.C. 401(k) Profit Sharing Plan in MN (1,183 participants). Same-state nearby plans are listed separately above.

Similar participant headcount

Nearest other-state filings by covered participants (1,183 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 Diamond Offshore 401(k) Plan assets move in 2023? ▼
Diamond Offshore 401(k) Plan grew at a solid clip - up 11.4% during 2023, from $319M to $356M. Reported net income was $36M.
How have Diamond Offshore Management Company plan assets changed over time? ▼
Across 3 plan years on file (2022-2024), Diamond Offshore Management Company's sponsor-wide assets grew 18.2%, from $319M to $377M.
Where does Diamond Offshore 401(k) Plan rank by assets among Form 5500 filers? ▼
Diamond Offshore 401(k) Plan ranks in the 97th percentile by end-of-year assets among 127,072 plans that reported assets for plan year 2023 (in the top 5% of all filed plans by assets).
Which 401(k) plans are similar in size to Diamond Offshore 401(k) Plan? ▼
Among 401(k) plans in other states, the closest by assets is The Safe Harbor 401(k) Plan in NY ($356M, 1,940 participants).
Which 401(k) plans cover a similar participant headcount to Diamond Offshore 401(k) Plan? ▼
Among 401(k) plans in other states, the closest by covered participants is The Polyclinic a P.C. 401(k) Profit Sharing Plan in MN (1,183 participants, N/A 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 133560049.

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.