Alnylam Pharmaceuticals, Inc. 401(k) Review & Grade
Alnylam Pharmaceuticals, Inc. Savings & Investment Plan
Cambridge, MAProfessional, Scientific & Technical Services1,752 active participantsPlan year 2024
Estimate from the plan's Form 5500 filing · How we grade
$8,368Employer $ per active participant
$18,146Employee $ saved per active participant
0.12%Direct admin cost, % of plan assets
$344.0MNet plan assets, end of year
$148,019Average balance per account
Score breakdown
- Employer generosity43.6 / 5087th percentile for employer $ per participant
- Low cost17.6 / 2570th percentile for low admin cost vs. same-size plans
- Employee saving14.5 / 1597th percentile for employee $ per participant
- Plan features3 / 10Default investment
- Red-flag deductions-3 pts1 issue reported on the filing
Total score76 / 100 · Grade A
This plan vs. peers
Peers: Professional, Scientific & Technical Services plans with 500–2,499 active participants (1,469 plans).
| Measure | Percentile |
|---|---|
| Employer $ per participant | 87th |
| Lower admin cost | 70th |
| Employee saving | 97th |
| Peers that auto-enroll | 48% |
Get the monthly 401(k) report card
The best and worst plans, new grades as filings post. One email a month, no spam.
Red flags from the filing
Corrective distributions: the plan refunded $45,429 in contributions, which usually means it failed annual nondiscrimination testing.
What to do if you're in this plan
- Alnylam Pharmaceuticals put in about $8,368 per active participant, more than the typical peer ($3,082). Contribute at least enough to collect the full match. Skipping it leaves part of your pay on the table.
- The filing shows total dollars, not the match formula. Ask HR for the Summary Plan Description so you know the exact match and vesting schedule.
- Fund expense ratios aren't in the filing. Look them up in your 404(a)(5) fee disclosure and favor low-cost index or target-date funds.
- Changing jobs? You can usually leave the money in the plan, move it to your new employer's plan, or roll it into an IRA. Don't cash out: you'd owe taxes and possibly a 10% penalty.
The raw numbers from the filing
| Employer contributions | $14,660,673 |
| Participant (employee) contributions | $31,791,379 |
| Other contributions (incl. rollovers in) | $13,265,871 |
| Administrative expenses paid from the plan | $361,760 |
| Contract administrator fees | $600 |
| Investment advisory & management fees | $77,297 |
| Benefits paid out | $38,704,316 |
| Net assets, start / end of year | $275.6M / $344.0M |
| Active participants, start / end of year | 1,689 / 1,815 |
| Participants with account balances | 2,324 |
| Auto-enrollment (feature code 2S) | Not reported |
| Auditor | RSM US LLP |
| Employer stock held by plan | $25,014,439 |
Largest service providers (Schedule C)
| Fidelity Investments Institutional | $250,302 reported compensation |
| Merrill Lynch Pierce Fenner & Smit | $77,297 reported compensation |
| RSM US LLP | $34,125 reported compensation |
Source: DOL EFAST2 Form 5500 filing, acknowledgment ID 20251010123920NAL0017964994001, received 2025-10-10, EIN 04-3696884, plan #001, plan year 2024-01-01 to 2024-12-31. Verify at efast.dol.gov.