Mersana Therapeutics, Inc.401(k)
MERSANA THERAPEUTICS, INC. 401(K) PROFIT SHARING PLAN TRUST · CAMBRIDGE, MA · plan year 2025
Peer grade: A · admin costs + employer contributions vs same-size plans · how grading works
Mersana Therapeutics, Inc. reported $6,250 in plan administrative expenses for 2025: 0.02% of average plan assets, lower than ~75% of peers. Employer contributions averaged $12,521 per active participant. This ratio covers administrative expenses reported on the plan's Schedule H only; fund-level expense ratios are not included in public structured data — see methodology.
Across the 3 years on file its reported administrative ratio rose from 0.018% to 0.020%. The plan sits in the $10M–$50M size bracket, benchmarked here against 1,620 comparable plans and shown alongside other professional & technical services employers. By assets it is the 950th-largest of 2,726 plans among Massachusetts employers on file, and the 3,904th of 11,654 in professional & technical services. In 2025, employees put in $2.93 for every $1.00 the employer contributed; active participation has shrunk from 231 to 42 since 2022.
Mersana Therapeutics, Inc.'s 2025 employer contribution ran above the $2,666 median for plans its size, placing it in the top quarter of its peers. Filings report dollars actually contributed, not the match formula; the formula itself (for example, 50% of the first 6% of pay) lives in the plan's summary plan description from HR.
Annual cost at the plan's reported 2025 administrative ratio, against the median plan its size; fund expense ratios are extra. Compare any plan.
Compensation shown is direct payments from plan assets reported on Schedule C. Providers paid through fund revenue-sharing appear as indirect.
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Source: U.S. Department of Labor, Form 5500 series, EIN 043562403 · Verify on EFAST2 · Amounts are as reported by the plan sponsor for the plan year shown.