If you sponsor a retirement plan, you're already a fiduciary—whether you've thought about it in those terms or not. The question isn't whether fiduciary responsibility exists; it's who's carrying it, and how much of it you're equipped to carry yourself. That's where 3(16), 3(21), and 3(38) services come in, and where a lot of business owners get the distinctions wrong.
The three numbers, briefly
ERISA identifies different categories of fiduciary responsibility by section number, and each one delegates a different slice of the job:
- 3(21) fiduciary provides investment advice and recommendations, but the plan sponsor retains final decision-making authority and the associated liability.
- 3(38) investment manager takes on full discretionary authority for selecting and monitoring plan investments—this is a genuine transfer of investment-related liability away from the sponsor.
- 3(16) plan administrator is different from both. It covers the day-to-day operational and administrative duties of running the plan—not investment decisions, but the mechanics of keeping the plan compliant.
What a 3(16) fiduciary actually takes off your plate
This is where the confusion tends to live, because "administrator" sounds minor and it isn't. A 3(16) fiduciary can assume responsibility for tasks like:
- Timely and accurate processing of participant enrollments, loans, and distributions
- Reviewing and approving eligibility determinations
- Signing and filing the plan's Form 5500
- Issuing required participant notices (safe harbor, QDIA, blackout, and others) on schedule
- Monitoring for and correcting compliance failures
- Serving as the named fiduciary for these operational functions—meaning the liability for getting them right shifts to the 3(16) provider, not just the workload
That last point is the one most business owners miss. Handing off tasks to a TPA or payroll provider is not the same as handing off fiduciary liability. Plenty of plan sponsors believe they've delegated responsibility when they've only delegated labor—the legal exposure for errors is still sitting with them.
What you're not delegating
A 3(16) engagement doesn't cover investment selection or monitoring (that's 3(21) or 3(38) territory), and it doesn't relieve the plan sponsor of the fiduciary duty to prudently select and monitor the 3(16) provider itself. You remain responsible for choosing a competent administrator and periodically confirming they're doing the job—but you're no longer personally on the hook for every enrollment form processed correctly or every notice mailed on time.
Why this matters more as plans grow
Administrative fiduciary risk scales with complexity: more employees, more life events (loans, hardship withdrawals, terminations), more notices, more deadlines. A business owner running payroll, managing projects, and reviewing plan paperwork on the side is a realistic recipe for a missed deadline or a mishandled distribution—exactly the kind of error that draws DOL or IRS attention during an audit.
The question to ask your current provider
Ask directly: "If a required notice goes out late, or a distribution is processed incorrectly, who is the named fiduciary responsible for that error—me, or you?" If the honest answer is "you," you likely don't have a true 3(16) arrangement, regardless of what the service is called in your paperwork.
The bottom line
3(16), 3(21), and 3(38) aren't interchangeable jargon—they represent genuinely different transfers of responsibility. Understanding which ones your plan actually has in place, versus which ones you assume you have, is one of the more consequential five-minute conversations a plan sponsor can have.
Not sure which fiduciary services your current plan actually includes?
Schedule a call with StatonWalsh for a plain-language review of your plan's fiduciary structure.