Mersana Therapeutics 401(k) match, vesting and fees
What Mersana Therapeutics' 401(k) plan says about matching contributions
Plan features
Match, vesting and enrollment details have not been published from this plan's audit report yet. The figures below come from the structured filing.
| Recordkeeper | Fidelity Investments Institutional | Schedule C ↗ |
| Independent auditor | Carron & Bletzer, PLLC (unmodified opinion, limited scope) | Schedule H ↗ |
| Plan type and status | 401(k) · Active | Form 5500 ↗ |
How the plan compares
Plan year 2025 medians for 3,569 defined-contribution plans in professional, scientific, and technical services with 100 to 499 participants.
| Mersana Therapeutics: employer contribution per participant | $2,889 | |
| Peer median | $2,719 |
| Mersana Therapeutics: average balance | $178,866 | |
| Peer median | $85,424 |
| Mersana Therapeutics: admin expenses ÷ assets | 0.02% | |
| Peer median | 0.27% |
Admin expenses are the plan's reported administrative expenses divided by its assets; they do not include fund expense ratios.
Plan history
Plan assets went from $20.1M at the end of plan year 2021 to $32.6M at the end of plan year 2025.
| Plan year | Participants | Assets | Employer contributions | Per participant | Admin expense ratio | Match formula | Filing |
|---|---|---|---|---|---|---|---|
| 2025 | 184 | $32.6M | $526K | $2,889 | 0.02% | Not published | Form 5500 ↗ |
| 2024 | 223 | $31.5M | $746K | $3,393 | <0.01% | Not published | Form 5500 ↗ |
| 2023 | 264 | $29.1M | $1.3M | $5,202 | <0.01% | Not published | Form 5500 ↗ |
| 2022 | 285 | $22M | $1.1M | $4,263 | 0.02% | Not published | Form 5500 ↗ |
| 2021 | 206 | $20.1M | $764K | $4,196 | 0.01% | Not published | Form 5500 ↗ |
Common questions
Does Mersana Therapeutics match 401(k) contributions?
The match terms for the Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust have not been published from its filing yet. The plan year 2025 filing reports $526K in employer contributions, about $2,889 per participant. That total includes any match and profit-sharing; it is not a match formula.
When is the Mersana Therapeutics 401(k) match vested?
The vesting schedule for the Mersana Therapeutics, Inc. 401(k) Profit Sharing Plan Trust is not in the data published so far. Your Summary Plan Description states it.
Who manages the Mersana Therapeutics 401(k)?
The recordkeeper listed on Schedule C of the plan year 2025 filing is Fidelity Investments Institutional. The plan administrator is Mersana Therapeutics, Inc..
I left Mersana Therapeutics. How do I find my old 401(k)?
Your account stays in the plan until you move it. Contact the plan administrator (Mersana Therapeutics, Inc., (617) 715-8200) or the recordkeeper, Fidelity Investments Institutional. The Mersana Therapeutics old 401(k) page lists the contacts from every plan filing. Find an old Mersana Therapeutics 401(k)
Data from the public Form 5500 annual reports Mersana Therapeutics filed with the U.S. Department of Labor (plan years 2021 and 2022 and 2023 and 2024 and 2025) and, where noted, the attached independent auditor's report. Plan terms may have changed since the filing; check your current Summary Plan Description. PlanFacts is not affiliated with Mersana Therapeutics. Not financial advice. Report a correction · Methodology