Why this matters

In my experience working with retirement plan sponsors, the biggest surprises rarely come from plan investments or day-to-day administration, but instead occur during the final stages of the plan’s lifecycle. Many employers assume that once leadership approves a termination or merger, the “hard part” is over. In reality, this transition period often presents heightened compliance, fiduciary and audit risk. 

Under IRS and Department of Labor requirements, a retirement plan generally remains active until all assets have been distributed and final compliance obligations have been satisfied. As a result, plan sponsors may still be responsible for testing, reporting, corrections, and fiduciary oversight well after an internal decision has been made. I’ve seen well-run companies stumble here because they didn’t realize the IRS and Department of Labor still treat the plan as active until every compliance box is checked and every dollar is properly distributed.

Is plan termination immediate?

One of the most common misconceptions is that a plan is “terminated” when leadership decides to discontinue it. Under IRS rules, however, a 401(k) plan is not considered terminated until all assets are fully distributed and required reporting is completed. 

Until that process is finalized, sponsors should expect ongoing obligations, including:

• Continued Form 5500 filing requirements
• Required amendments
• Final employer contributions, true-ups, or corrections
• Ongoing fiduciary responsibilities

Employers are often surprised to learn that even after communicating a closure internally, compliance responsibilities may still remain.

Common audit & compliance pitfalls during plan terminations and mergers

While every plan transition is different, audit and compliance issues often emerge in a few predictable areas:

1. Timing gaps in contributions and vesting- One of the most common issues is assuming contributions can simply stop immediately once a termination or merger decision is made, without reconciling what’s already owed. Final employer contributions, true-ups, and vesting acceleration often create last-minute adjustments that must be resolved before distributions can happen.
2. “We’ll just file the final Form 5500 now”- This is a frequent mistake. Filing a final Form 5500 too early (before all assets are distributed) can trigger compliance issues, create confusion during IRS or DOL review and may require amended filings or additional explanations later. Timing is often more important than sponsors initially realize.
3. Merger ≠ clean exit- When a plan is merged into another retirement plan, employers often assume responsibilities transfer seamlessly to the receiving plan. In reality, the receiving plan still needs accurate participant data, properly allocated forfeitures, and reconciled participant balances. If anything is missing, it becomes a downstream audit issue for the successor plan.

What we see in practice 

In one instance, I worked with a mid-sized company that was acquired and needed to merge its 401(k) plan into the acquiring company’s existing plan. On paper, it looked straightforward: freeze the old plan, transfer assets, and complete the merger within a few months.

However, once we reviewed the plan in detail, we found:

• Outstanding employer match true-ups that had not been funded
• Forfeiture accounts that had not been properly allocated
• Participant records with inconsistent vesting information
• A planned “final” Form 5500 that had been prepared before all distributions were completed 

While none of these issues were intentional, collectively they delayed the merger and required additional reconciliation work before assets could be transferred appropriately. The acquiring company ultimately had to slow down integration just to ensure the compliance foundation was correct.

Why audit readiness becomes more important at the end of a plan

When a plan is ongoing, compliance responsibilities are spread out throughout the year. During a termination or merger, those same requirements are compressed into a much shorter timeframe. 

That compression increases risk because errors become more visible, missing documentation becomes harder to reconstruct, deadlines become less flexible and regulators expect finality and precision. In many ways, the end of a plan lifecycle is when the details matter most.

A better way to approach a plan termination or merger

The companies that navigate this process successfully tend to treat a termination or merger like a structured compliance project, not simply an administrative task. That includes:

• Confirming final contributions and corrections early
• Reconciling participant data before distributions begin
• Coordinating across legal, payroll, and retirement plan teams
• Aligning audit readiness with the termination or merger timeline
• Avoiding assumptions around filing requirements or timing

When addressed proactively, the process is typically smoother, less disruptive, and less costly to unwind later. A retirement plan termination or merger is often viewed as an endpoint. From a compliance perspective, however, it is one of the most sensitive phases in the plan’s lifecycle. Getting it right helps protect participants, reduce fiduciary risk, and ensure the plan is fully and properly closed.