401(k) · DOL Form 5500 · 2024
Iron Mountain Incorporated 401(k) Plan
Data updated 2026-08-06
- $943M
- Total assets
- 9,146
- Participants
- 98th
- Percentile by assets
- $103,118
- Avg per participant
Official DOL plan name: The Iron Mountain Companies 401(k) Plan · Sponsored by Iron Mountain Incorporated · Pennsylvania · Transportation & Warehousing
$943M in assets, 9,146 participants
Iron Mountain Incorporated's The Iron Mountain Companies 401(k) Plan reported $943M in total assets and 9,146 participants in its 2024 DOL Form 5500 filing, ranking in the 98th 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.
- 98th percentile by assets (of 116,472 plans)
Coverage in Pennsylvania
The Iron Mountain Companies 401(k) Plan covers 9,146 participants in Pennsylvania, 11x the typical Pennsylvania plan (state average ~824 per filing). Assets: $943M.
- $943M
- total plan assets (2024 EOY)
- 9,146
- covered participants
- 98th
- percentile by assets (of 116,472 plans)
- $103,118
- avg assets per participant
What changed between DOL Form 5500 filings
plan year 2023 → plan year 2024
- The Iron Mountain Companies 401(k) Plan end-of-year assets rose from $805M in the plan year 2023 filing to $943M in the plan year 2024 filing.
- The Iron Mountain Companies 401(k) Plan reported net income fell from $151M in the plan year 2023 filing to $139M in the plan year 2024 filing.
- The Iron Mountain Companies 401(k) Plan reported participants rose from 8,643 in the plan year 2023 filing to 9,146 in the plan year 2024 filing.
Participants vs Pennsylvania filers
In Pennsylvania, the average filing covers about 824 participants across 5,360 plans. The Iron Mountain Companies 401(k) Plan reports 9,146 participants - 11x that state average ($943M EOY assets).
Pennsylvania filing particulars
| Total Assets (Beginning of Year) | $805M |
|---|---|
| Net Assets (End of Year) | $943M |
| Net Income | $139M |
| Employer EIN | 232588479 |
| Plan Effective Date | 1988-11-09 |
| Filing Status | FILING RECEIVED |
Sponsor Plan History (Iron Mountain Incorporated)
| Year | Plans | Participants | Total Assets |
|---|---|---|---|
| 2022 | 1 | 7,917 | $651M |
| 2023 | 1 | 8,643 | $805M |
| 2024 | 1 | 9,146 | $943M |
Nearby 401(k) Plans in Pennsylvania
Peer 401(k) plans, same state, same plan type, ranked by total assets.
The Iron Mountain Companies 401(k) Plan vs. nearby 401(k) plans in Pennsylvania, assets vs. participants
- Comcast Corporation Retirement - Investment Plan $19.7B · 90,495
- The Cigna Group 401(k) Plan $14.2B · 63,634
- The Vanguard Retirement and Savings Plan $11.1B · 18,066
- Thermo Fisher Scientific Inc. 401(k) Retirement Plan $10.3B · 36,150
- The PNC Financial Services Group, Inc. Incentive Savings Plan $10.2B · 54,604
Similar-Sized 401(k) Plans Nationally
401(k) plans in other states closest to The Iron Mountain Companies 401(k) Plan by total assets, not by location.
- Cemex, Inc. Savings Plan (TX) $942M · 8,349
- Bunzl USA, LLC Deferred Savings Plan (MO) $942M · 5,486
- Insight Enterprises, Inc. 401(k) Plan (AZ) $942M · 6,405
- Southeastern Grocers 401(k) Savings Plan (FL) $941M · 26,424
Frequently Asked Questions
How did The Iron Mountain Companies 401(k) Plan assets move in 2024? ▼
How have Iron Mountain Incorporated plan assets changed over time? ▼
Where does The Iron Mountain Companies 401(k) Plan rank by assets among Form 5500 filers? ▼
Which 401(k) plans are similar in size to The Iron Mountain Companies 401(k) Plan? ▼
Next read for The Iron Mountain Companies 401(k) Plan
Filing takeaways
Ways to act on The Iron Mountain Companies 401(k) Plan's numbers.
- By total assets, The Iron Mountain Companies 401(k) Plan ranks in the top 5% of all filed plans by assets. See the largest plans
- Compare it side-by-side against 3 similar 401(k) plans in Pennsylvania. Compare plans
- Iron Mountain Incorporated's sponsor-wide assets have grown 44.8% since 2022 across 3 plan years on file. More Transportation & Warehousing plans
Source: U.S. Department of Labor, Employee Benefits Security Administration (EBSA), Form 5500 public disclosure dataset. Plan year 2024.
Source: DOL EFAST2 filing system (efast.dol.gov) - original filing retrieval by EIN 232588479.
Read our methodology - how this data is sourced, computed, and verified.