Who uses Iron Mountain?

54 retirement plans list Iron Mountain as a service provider on Schedule C of Form 5500. The largest clients by plan assets include Board of Trustees of the I.A.M. National Pension Fund, Board of Trustees Eastern Atlantic States Carpenters Pension Fund, B/O/T United Association National Pension Fund, Board of Trustees, Western Unite Here and Employers and Board of Trustees, California Ironworkers Field Pension Trust Fun. Most client plans are sponsored in CA, WA and OR.

How many plans does Iron Mountain serve?

Iron Mountain serves 54 retirement plans with $77.6B in plan assets and 1,332,735 participants, based on the latest Form 5500 filings through 2024.

What does Iron Mountain charge?

Plans reported $2.0M in total Schedule C compensation paid to Iron Mountain. The median plan paid $16K. Fees vary with plan size and the services each plan buys.

Filings through Oct 24, 2026.

Iron Mountain

Matched across 19 name variants in the filings

Iron Mountain summary

Iron Mountain appears on 54 retirement plans in Form 5500 Schedule C filings through plan year 2024. Those plans hold $77.6B in assets for 1,332,735 participants. The median client plan holds $549M. Most client plans are sponsored in CA, WA and OR. The largest clients by plan assets are Board of Trustees of the I.A.M. National Pension Fund, Board of Trustees Eastern Atlantic States Carpenters Pension Fund and B/O/T United Association National Pension Fund. Plans reported $2.0M in direct and indirect compensation paid to Iron Mountain. The median is $16K per plan.

Participants: 1,332,735
Median plan assets: $549M
Median plan participants: 6,159
Median fees per plan: $16K; Schedule C direct + indirect

Top 25 client plans by assets

Latest Form 5500 filing per plan through 2024

Sponsor	State	Assets	Participants
Board of Trustees of the I.A.M. National Pension Fund	DC	$16.0B	307,518
Board of Trustees Eastern Atlantic States Carpenters Pension Fund	PA	$7.8B	65,862
B/O/T United Association National Pension Fund	VA	$7.7B	196,837
Board of Trustees, Western Unite Here and Employers	CA	$4.0B	158,780
Board of Trustees, California Ironworkers Field Pension Trust Fun	CA	$3.5B	21,447
Board of Trustees of the American Federation of Musicians and Employe	NY	$3.3B	52,901
Board of Trustees NY Hotel Trades Council and Hotel Assn.	NY	$3.0B	57,265
Trustees of NYS Teamsters Conference	NY	$2.9B	32,032
Board of Trustees, Sound Retirement Trust	WA	$2.7B	107,493
Board of Trustees of Supplemental Income Trust Fund	CA	$2.1B	43,977
Sheet Metal Workers Pension Trust	CA	$1.7B	13,026
Bot, Western Wa Laborers-Employers Pension Trust	WA	$1.6B	20,130
Carpenters Pension Trust Fund of Kansas City	MO	$1.5B	13,466
U a Local Union Officers & Employees Pension Fund	MD	$1.4B	6,198
Bot, Wa State Plumbing and Pipefitting Industry Pension Plan	WA	$1.4B	10,882
Board of Trustees, Eighth District Electrical Pension, plan 002	NV	$1.3B	24,505
Board of Trustees, California Iron Workers Field Defined Contribution	CA	$1.3B	27,522
Board of Trustees, Eighth District Electrical Pension, plan 001	NV	$1.3B	21,064
Laborers' District Council Construction Industry Pension Fund	PA	$1.2B	9,405
The Procter and Gamble Company	OH	$1.1B	10,655
Board of Trustees Retirement Plan for Hospital Employees	CA	$1.1B	11,180
Bay Area Painters and Tapers Pension Trust Fund	CA	$775M	8,397
Board of Trustees of the Western Wa U.A. Supplemental Pension Plan	WA	$759M	7,008
Board of Trustees Iron Workers	MA	$758M	4,855
Board of Trustees Iron Workers	MA	$653M	10,148

Board of Trustees of the I.A.M. National Pension Fund$16.0B
DCParticipants 307,518
Board of Trustees Eastern Atlantic States Carpenters Pension Fund$7.8B
PAParticipants 65,862
B/O/T United Association National Pension Fund$7.7B
VAParticipants 196,837
Board of Trustees, Western Unite Here and Employers$4.0B
CAParticipants 158,780
Board of Trustees, California Ironworkers Field Pension Trust Fun$3.5B
CAParticipants 21,447
Board of Trustees of the American Federation of Musicians and Employe$3.3B
NYParticipants 52,901
Board of Trustees NY Hotel Trades Council and Hotel Assn.$3.0B
NYParticipants 57,265
Trustees of NYS Teamsters Conference$2.9B
NYParticipants 32,032
Board of Trustees, Sound Retirement Trust$2.7B
WAParticipants 107,493
Board of Trustees of Supplemental Income Trust Fund$2.1B
CAParticipants 43,977
Sheet Metal Workers Pension Trust$1.7B
CAParticipants 13,026
Bot, Western Wa Laborers-Employers Pension Trust$1.6B
WAParticipants 20,130
Carpenters Pension Trust Fund of Kansas City$1.5B
MOParticipants 13,466
U a Local Union Officers & Employees Pension Fund$1.4B
MDParticipants 6,198
Bot, Wa State Plumbing and Pipefitting Industry Pension Plan$1.4B
WAParticipants 10,882
Board of Trustees, Eighth District Electrical Pension, plan 002$1.3B
NVParticipants 24,505
Board of Trustees, California Iron Workers Field Defined Contribution$1.3B
CAParticipants 27,522
Board of Trustees, Eighth District Electrical Pension, plan 001$1.3B
NVParticipants 21,064
Laborers' District Council Construction Industry Pension Fund$1.2B
PAParticipants 9,405
The Procter and Gamble Company$1.1B
OHParticipants 10,655
Board of Trustees Retirement Plan for Hospital Employees$1.1B
CAParticipants 11,180
Bay Area Painters and Tapers Pension Trust Fund$775M
CAParticipants 8,397
Board of Trustees of the Western Wa U.A. Supplemental Pension Plan$759M
WAParticipants 7,008
Board of Trustees Iron Workers$758M
MAParticipants 4,855
Board of Trustees Iron Workers$653M
MAParticipants 10,148

Top client states

CA19 plans
WA5 plans
OR4 plans
PA4 plans
MA3 plans

Frequently asked questions

Who uses Iron Mountain?: 54 retirement plans list Iron Mountain as a service provider on Schedule C of Form 5500. The largest clients by plan assets include Board of Trustees of the I.A.M. National Pension Fund, Board of Trustees Eastern Atlantic States Carpenters Pension Fund, B/O/T United Association National Pension Fund, Board of Trustees, Western Unite Here and Employers and Board of Trustees, California Ironworkers Field Pension Trust Fun. Most client plans are sponsored in CA, WA and OR.
How many plans does Iron Mountain serve?: Iron Mountain serves 54 retirement plans with $77.6B in plan assets and 1,332,735 participants, based on the latest Form 5500 filings through 2024.
What does Iron Mountain charge?: Plans reported $2.0M in total Schedule C compensation paid to Iron Mountain. The median plan paid $16K. Fees vary with plan size and the services each plan buys.

Analytics

Market position · 2024

Plans served54+14 YoYRank #413 of mapped providers

Assets under administration$77.6B0.1%Rank #288 by share of filed assets

Fees received$2MMedian $16,336/planSum across Schedule C direct + indirect

Net wins YoY+312 won - 9 lostPlan-level switch detection

Plans served · 5-year trajectory

Plan count by year, with the share of all plans.

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Customer-base shape

Participant bands, asset bands, top states and top industries.

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Customer-base shape
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Top plans by assets

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