A DOL investigation letter about your 401(k) plan is one of the few pieces of mail that changes the next several months of a plan sponsor’s calendar. The Department of Labor’s Employee Benefits Security Administration (EBSA) is asking to see how your plan is actually run, and the person who signs the response is speaking for the plan’s fiduciaries. This guide walks through what the letter usually asks for, who should own the response, and how to organize the records so the investigation stays focused and ends cleanly.
Why a DOL Letter Is a Fiduciary Event, Not a Records Request
It is tempting to hand the letter to HR or forward it to the recordkeeper and ask them to “send what they need.” That is the most common early mistake. EBSA is not auditing your recordkeeper; it is reviewing whether the plan’s fiduciaries acted prudently, followed the plan document, and paid only reasonable expenses. Every document you produce becomes evidence of how those decisions were made.
Investigations can start for many reasons, including participant complaints, a pattern in Form 5500 data, a referral from another agency, or a regional enforcement project. The letter usually will not tell you why your plan was selected, so the safest assumption is that every area of plan operations is in scope.
Who Should Respond
The response should be coordinated by the person or committee with fiduciary authority over plan administration, not by whoever opened the mail. In practice that means:
- The plan administrator named in the plan document (often the employer itself, or a committee) owns the response.
- ERISA counsel should review the letter early, especially if it mentions specific transactions, late deposits or participant complaints.
- Service providers (recordkeeper, TPA, payroll, investment adviser) supply records, but they should not answer substantive questions on the plan’s behalf unless they hold that fiduciary role in writing.
If you are not sure who the named fiduciary is, read our explainer on who the 402(a) named fiduciary is before anything else goes out.
What the Letter Typically Asks Plan Sponsors to Produce
Document requests vary by investigation, but these categories appear again and again. Building the file in this order makes gaps visible fast.
1. Plan documents and amendments
The current plan document, adoption agreement, every signed amendment, and prior restatements for the years under review. Unsigned or missing amendments are a frequent finding; see plan document restatements.
2. Participant communications
The summary plan description, summaries of material modifications, automatic enrollment and safe harbor notices, and participant fee disclosures, plus proof of how and when each was delivered. Our guides on SPDs and SMMs and 404(a)(5) fee disclosures cover what each must contain.
3. Form 5500 filings and audit reports
Filed returns, schedules and, for plans above the participant-count threshold, the independent auditor’s report. Investigators compare the filings to your payroll and trust records, so discrepancies matter. If you have not looked closely at past filings, start with reviewing the Form 5500 before signing.
4. Contribution deposit records
Payroll dates matched to the dates deferrals and loan repayments reached the trust. Late deposits are one of the most common issues EBSA examines because the standard is the earliest date the money can reasonably be segregated from company assets. If you find late deposits, our guide to correcting late deferral deposits explains the fix.
5. Service provider contracts and fee disclosures
Agreements with every provider, the 408(b)(2) disclosures you received, and evidence that someone reviewed them for reasonableness. See 408(b)(2) fee disclosure review.
6. Investment oversight records
Your investment policy statement if you have one, fund performance and fee reviews, and committee minutes showing decisions and the reasons behind them. Minutes are often the single best evidence of a prudent process; see plan committee meeting minutes.
7. Fidelity bond and trust records
Your ERISA fidelity bond, trust statements, and records of distributions, loans and plan-paid expenses for the period under review.
A Step-by-Step Response Plan
- Calendar the response date stated in the letter and decide immediately whether you need to request more time. Ask for it in writing, early.
- Identify the fiduciary owner and engage ERISA counsel to review the request before anything is produced.
- Issue a document hold so no one deletes emails, payroll files or committee materials covering the review period.
- Request records from each provider in writing, listing exactly what you need and by when.
- Build an index that maps every request item to the documents produced, with a note where something does not exist.
- Review before producing. Read every document as an investigator would. If you spot an error, talk to counsel about correcting it, possibly through the Voluntary Fiduciary Correction Program or IRS correction programs where appropriate.
- Produce exactly what was requested, organized and labeled, and keep a copy of the full production.
- Prepare for interviews. Investigators may ask to speak with the people who run the plan day to day. They should be able to explain the process, not just the paperwork.
Where Plan Sponsors Get Hurt
- Letting a provider answer for the plan. Providers can explain their own services, but they cannot speak to decisions the employer made.
- Producing more than requested. Unorganized “data dumps” invite new questions and make the investigation longer.
- No evidence of process. A reasonable fee or fund lineup is far harder to defend when no one wrote down how it was chosen.
- Discovering problems mid-investigation. Late deposits, missed notices or document-versus-practice mismatches found for the first time during the response are much harder to correct on your own terms.
- Treating the closing letter as the end. If the investigation identifies issues, corrections and follow-up typically continue after the review closes.
What You Can Delegate and What Stays With the Employer
A 3(16) administrator can manage the document collection, reconcile deposits against payroll, organize the index and sit alongside you through the process. Some things only the employer can supply: payroll records, hours data, information about its own business decisions, and settlor choices such as plan design and amendments. Understanding that split ahead of time is the difference between a contained review and a scramble. Our guide to 3(16) vs. 3(21) vs. 3(38) vs. 402(a) lays out each role.
The best time to prepare for a DOL letter is before one arrives. A plan that keeps a current document file, deposit reconciliations and committee minutes can usually answer a request from existing records. Our 401(k) plan audit readiness checklist is a good place to start.
How Admin316 Helps
Admin316 provides full 3(16) plan administration for employer plan sponsors, including the documentation, deposit monitoring and notice tracking that investigators look for. Unlike most providers, Admin316 also accepts appointment as the plan’s ERISA 402(a) named fiduciary, so a qualified fiduciary owns plan administration and stands with you when the Department of Labor asks how the plan is run.
If a DOL investigation letter has arrived, or you want to be ready before one does, book a call with the Admin316 team.
