401(k) · DOL Form 5500 · 2023

Mersana Therapeutics, Inc. 401(k) Plan

Data updated 2026-08-25

$29M
Total assets Below avg plan size
231
Participants Below avg headcount
79th
Percentile by assets National rank
$126,172
Avg per participant Near avg balance/head
PlainRetire home → About this data RSS: change history

Official DOL plan name: Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust · Sponsored by Mersana Therapeutics, Inc. · Massachusetts · Professional & Technical Services

$29M in assets, 231 participants

Mersana Therapeutics, Inc.'s Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust reported $29M in total assets and 231 participants in its 2023 DOL Form 5500 filing, ranking in the 79th 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.

  • #16,099 in Professional & Technical Services (20,321 peers)

Coverage in Massachusetts

Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust covers 231 participants in Massachusetts, about 35% of the average Massachusetts filer (state average ~659 per filing). Assets: $29M.

#16,099
in Professional & Technical Services (20,321 peers)
+32.6%
assets growth YoY
0.3×
vs typical plan assets (national mean)

Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust's outsized position by total assets

Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust vs every filed plan by assets

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

$29,145,736 Top 21% higher than 79% 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

Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust among mid-size filed plans by headcount

Plan-year 2023 Form 5500 filings with a reported participant count, partitioned by headcount band, not by assets. Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust sits mid-pack in the medium band (231 participants).

What changed between DOL Form 5500 filings

plan year 2022 → plan year 2023

  • Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust reported net income rose from $2M in the plan year 2022 filing to $7M in the plan year 2023 filing.
  • Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust reported participants rose from 163 in the plan year 2022 filing to 231 in the plan year 2023 filing.
  • Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust end-of-year assets rose from $22M in the plan year 2022 filing to $29M in the plan year 2023 filing.

See the national 2022→2023 release diff →

Plan-year Form 5500 strip

Filing strip 043562403 · Mersana Therapeutics, Inc. PY 2023 · 401(k)

Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust · $29M · 231 · 79th

  • RANK $29M
  • RANK 231
  • RANK 79th
  • RANK 401(k)
  • RANK near Strava, Inc. Retirement Trust
  • RANK ind #16099

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 Massachusetts →

Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust in the asset neighbourhood

Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan TrustMersana Therapeutics, Inc. 4…$29MStrava, Inc. Retirement Trust$29MHallam Associates, Inc. Profit Sharing and Savings PlanHallam Associates, Inc. Prof…$29MAvesis Retirement Investment PlanAvesis Retirement Investment…$29MHorizons 401(k) Plan$29M
End-of-year total assets ($M) among Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust and nearest nationwide 401(k) peers. Source: DOL Form 5500 plan year 2023.

Massachusetts filing particulars

Total Assets (Beginning of Year)$22M
Net Assets (End of Year)$29M
Net Income$7M
Employer EIN043562403
Plan Effective Date2006-01-01
Filing StatusFILING RECEIVED

Sponsor Plan History (Mersana Therapeutics, Inc.)

Sponsor-wide plan assets over time

All Mersana Therapeutics, Inc. plans reported in each filing year

Latest sponsor-wide plan assets
$32M 43.43299919332445% vs 2022
2024 filing year
$20M$25M$30M$35M 202220232024 $22M $31.5M ▲ +43.4%
Year Plans Participants Total Assets
2022 1 163 $22M
2023 1 231 $29M
2024 1 122 $32M

Nearby 401(k) Plans in Massachusetts

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

Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust vs. nearby 401(k) plans in Massachusetts, assets vs. participants Scatter plot of 6 data points. -20000020000400006000080000 -10010203040 Total assets ($B) Participants Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust, Total assets ($B): 0.029145736 · Participants: 231Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan TrustFidelity Retirement Savings Plan, Total assets ($B): 28.649852331 · Participants: 62289Fidelity Retirement Savings PlanLiberty Mutual 401(k) Plan, Total assets ($B): 10.556596852 · Participants: 37052Liberty Mutual 401(k) PlanMassachusetts Institute of Technology Supplemental 401(k) Plan, Total assets ($B): 6.829912863 · Participants: 14094Massachusetts Institute of Technology Supplemental 401(k) PlanBoston Scientific Corporation 401(k) Retirement Savings Plan, Total assets ($B): 5.786107181 · Participants: 19881Boston Scientific Corporation 401(k) Retirement Savings PlanPhilips North America 401(k) Plan, Total assets ($B): 5.779286156 · Participants: 19120Philips North America 401(k) Plan
Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust vs. nearby 401(k) plans in Massachusetts, assets vs. participants
Compare Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust side-by-side with 3 peers →

Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust's out-of-state 401(k) peers by assets and headcount

Outside Massachusetts, the nearest 401(k) by assets is Strava, Inc. Retirement Trust in CA ($29M); by covered participants it is Teacher Synergy LLC 401(k) Plan in NY (231 participants). Same-state nearby plans are listed separately above.

Closest by plan assets

Nearest other-state filings by tot_assets_eoy ($29M here).

Similar participant headcount

Nearest other-state filings by covered participants (231 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 Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust assets move in 2023? ▼
Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust surged - up 32.6% during 2023, from $22M to $29M. Reported net income was $7M.
How have Mersana Therapeutics, Inc. plan assets changed over time? ▼
Across 3 plan years on file (2022-2024), Mersana Therapeutics, Inc.'s sponsor-wide assets grew 43.4%, from $22M to $32M.
Where does Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust rank by assets among Form 5500 filers? ▼
Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust ranks in the 79th percentile by end-of-year assets among 127,072 plans that reported assets for plan year 2023 (in the top quartile of all filed plans by assets).
Which 401(k) plans are similar in size to Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust? ▼
Among 401(k) plans in other states, the closest by assets is Strava, Inc. Retirement Trust in CA ($29M, 325 participants).
Which 401(k) plans cover a similar participant headcount to Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust? ▼
Among 401(k) plans in other states, the closest by covered participants is Teacher Synergy LLC 401(k) Plan in NY (231 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 043562403.

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.