Disclosure: ADP District Manager here. I'll be straight on the rules and the operator reality.
The 100-participant trigger you crossed is real and the filing requirement is non-optional. Here's the actual breakdown:
When you have to file Form 5500:
- 100+ participants in a welfare benefit plan (health, dental, vision, life, AD&D, etc.) at the START of the plan year = full Form 5500 with all schedules.
- 100+ participants in a retirement plan (401k, 403b) = Form 5500 with required schedules.
- 'Participant' includes anyone eligible to enroll, NOT just currently enrolled. So if 110 employees are eligible for health insurance but only 70 enrolled, you're still over the threshold.
- The 80-120 rule: if you were under 100 last year and crossed 100 this year, you can file as a small plan (5500-SF) until you exceed 120. Useful runway.
What goes in the filing:
- Form 5500 main form (plan info, sponsor info, broker fees, carrier info)
- Schedule A for each insurance contract (one per carrier — medical, dental, vision, life all get their own Schedule A)
- Schedule C for service provider compensation (TPAs, brokers, consultants — required when total comp ≥ $5K from the plan)
- Schedule H for plans with 100+ participants (financial info — assets, liabilities, transactions)
- Independent qualified public accountant (IQPA) audit report — REQUIRED for plans with 100+ participants at year-start. This is the expensive part — audits run $7K-25K depending on plan complexity.
Real cost reality at 100-120 participants:
- Broker handling the filing: $2-3K typical. Worth it if your broker's good.
- Independent CPA audit: $7-15K. Required at 100+ participants. Non-negotiable.
- TPA prep work: $1-3K if you have a TPA.
- Total first-year cost: $10-20K assuming you're not doing the audit yourself.
The penalty story (because this is what people actually ask):
- DOL penalty for late filing: up to $2,739/day per filing, capped at much higher amounts. In practice, the DOL rarely assesses the full amount on first-time late filers — they prefer compliance over revenue.
- The Delinquent Filer Voluntary Compliance (DFVC) program lets late filers self-report at much lower penalties — $750-2,000 typical. If you missed a deadline, file under DFVC immediately, don't wait for the DOL letter.
- IRS penalty: separate from DOL, $250/day for missed returns, capped at $150K. Less commonly enforced but possible.
- Audit triggers: late filings DO increase audit risk. The DOL specifically uses filing-pattern anomalies as audit triggers.
What surprises people:
- Brokers often don't actually 'handle' the filing. They prep the data and send it to you to file. Make sure you're getting the EFAST2 submission, not just a draft 5500. If the broker says 'I file it,' verify they have an EFAST2 credential under your plan.
- The Schedule A reveals everything. Your Form 5500 Schedule A publicly discloses your broker commissions, your carrier, your plan participants, your premiums. Anyone (vendors, competitors, FOIA requesters) can pull this data from the DOL. This is actually how vendors like me find out what you're paying.
- The audit isn't just a stamp. The CPA audits plan financials, internal controls, eligibility tracking, contributions vs. participants reconciliation. If you have sloppy enrollment data, the audit surfaces it and you may need to remediate before filing.
Practical advice:
- $2K broker handling is reasonable if they actually do the filing AND coordinate with your CPA auditor. If they're just prepping the draft, that's not worth $2K.
- Find a CPA who specializes in employee benefit plan audits, NOT your regular tax CPA. There's a specific AICPA designation (Employee Benefit Plan Audit Quality Center) — look for that. Specialist auditors finish faster and find fewer 'surprise' findings.
- Build a 5500 calendar starting October — most plans have a July 31 (or extended Oct 15) filing deadline for calendar-year plans. Starting in October leaves zero buffer for surprises.
One more thing: at 100+ participants you also have summary annual report (SAR) distribution requirements — a one-page summary of the 5500 sent to every plan participant. Most filers miss this. Your broker or TPA should generate it; you have to distribute it.
— AJ