What Happens to Your Company 401(k) When You Sell? Terminate Before Closing or Hand It to the Buyer

The plan generally either ends before closing or goes to the buyer. In a stock sale it generally transfers with the company unless you terminate it first. Terminate it, and every affected participant becomes 100% vested and assets generally go out within 12 months (IRS, updated 2026). Hand it over, and the buyer inherits its history, errors included.

The fork depends on what kind of deal it is

First, a stock sale. The buyer purchases the company itself, and the company is the plan sponsor. The 401(k) generally comes along. If nobody acts, it typically becomes the buyer’s plan when the deal closes, and whatever happened inside it over the last several years becomes the buyer’s problem. That is why it shows up on the diligence list.

Second, an asset sale. The buyer purchases equipment, contracts and customer lists, not the company, so the plan does not automatically move over. Employees who move to the buyer have separated from your company, which generally lets them take a distribution or roll their balance out. A client of mine who sold his business last year structured it as an asset sale, and his company 401(k) had to be terminated outright. The new owner started a brand-new plan instead of taking over the old one, and every employee had to roll over their own account. His description of it was that it was a lot of work, and that work landed on him and on every employee, not just the people negotiating the deal. If your entity does keep the plan, it can still be affected. Under Rev. Rul. 2007-43, the IRS treats a turnover rate of 20% or more as a rebuttable presumption that a partial termination occurred (IRS, Partial Termination of Plan page, reviewed September 2026). If that happens, everyone who left in that period becomes fully vested.

So the first question is not whether to terminate the plan. It is what you are actually selling, because deal structure, more than the fact of a sale, decides what happens to the plan.

Why the date on the termination resolution matters

The successor plan rule looks at whether the employer maintains another defined contribution plan at any time from the termination date through 12 months after the final distribution, which is why the timing of the termination date matters. If it does, the 401(k) cannot pay out deferrals on termination (Treas. Reg. § 1.401(k)-1(d)(4)(i), eCFR, current 2026).

Here is the mechanism that matters in a stock sale. The regulation measures who the employer is as of the date of plan termination. Terminate your plan the day after closing, and your company may now be treated as one employer with the buyer under the controlled group rules that the regulation borrows (26 CFR 1.401(k)-6 and 1.410(b)-9, which aggregate employers under IRC 414(b), (c), (m) and (o)), so the buyer’s 401(k) can count as the alternative plan. Your participants could lose the ability to take a termination distribution at all. Terminate it by board resolution effective before closing, and your company is still its own employer on that date.

There is a narrow exception. If fewer than 2% of the employees eligible under your plan are eligible under the other plan at all times during a 24-month period starting 12 months before termination, the other plan does not count (same regulation). ESOPs, SEPs, SIMPLE IRAs, 403(b) and 457 plans also do not count. Confirm which of these applies with ERISA counsel before the resolution is signed, not after.

Terminate or hand it over, side by side

Sources: IRS, Terminating a Retirement Plan, updated June 2026. Treas. Reg. § 1.401(k)-1(d)(4)(i), eCFR, current as of October 2026.

The condition under which handing it over is right

Letting the buyer take the plan is not the wrong answer. If your plan is clean, the buyer’s plan is at least as good for your employees, and the buyer actually wants your plan merged into theirs, then termination adds paperwork and a 12-month wind-down nobody needed. That is a real option, and some buyers prefer it.

But the buyer is only going to want that if the plan holds up under a look. A buyer’s counsel who finds a failed nondiscrimination test or late deposits can ask for the plan to be terminated before closing, or ask for an indemnity, or both. Either way, the history follows you into the negotiation.

What to clean up in the 12 months before a sale

This is the price of admission for either fork. If you want a real read on which way to go, I would need four things: the current plan document and any amendments, the last three years of Form 5500 filings and testing results, your payroll deposit records, and the 408(b)(2) fee disclosure.

First, deposit timing. For plans with fewer than 100 participants at the start of the plan year, the Department of Labor safe harbor deems amounts withheld from wages to be timely if they are deposited within 7 business days after the day the amount would otherwise have been paid to the participant in cash (29 CFR § 2510.3-102(a)(2), current 2026). A pattern of later deposits is the kind of thing that turns up in diligence. The DOL’s Voluntary Fiduciary Correction Program lists delinquent participant contributions among the problems it covers (DOL, VFCP page), and starting a year out leaves far more room to work through it than starting a month out.

Second, testing history. A failed ADP/ACP test that was never corrected, or a top-heavy minimum contribution that was missed, may still need correcting after the company changes hands. The IRS Employee Plans Compliance Resolution System (EPCRS) lets a plan sponsor fix plan mistakes through self-correction or a voluntary correction filing, and the IRS fix-it guide for failed ADP and ACP tests describes both routes (IRS, reviewed July 2026). Your TPA can tell you which apply.

Third, the plan document itself. The IRS, on its Terminating a Retirement Plan page (updated June 2026), states it plainly: “A qualified retirement plan that has not distributed its assets is considered an ongoing plan.” That means a terminating plan still has to be amended for law changes until the last balance is paid out.

Fourth, participants. Outstanding loans, missing former employees and uncashed checks all slow a final distribution. Every one of them is easier to resolve while you still have full access to payroll and HR records.

You are still the fiduciary until the money leaves

Terminating the plan does not end the job. The IRS position quoted above is the practical version of this: until assets are distributed, the plan is ongoing, and someone is still responsible for it.

An anonymized case from my own work: an HR manager named as trustee on the company’s 401(k) who had no idea the title carried personal fiduciary liability. That gap matters more in a sale, not less. The owner is focused on closing, the staff is focused on what happens to their jobs, and the person whose name is on the trust document may not know they are still on the hook during the wind-down. Confirm who holds that role, and whether they know it, before the letter of intent is signed. This is general education, not legal or tax advice. Plan termination and deal structure decisions belong with your ERISA attorney and CPA.

For the broader view of what drives a business’s readiness before a transaction, see exit readiness for San Diego business owners. If you are still working out what a buyer is actually paying for, what actually determines what your business is worth covers that side. How a buyer treats your plan contributions when it prices the business is its own question, covered in retirement plan contributions as an add-back.

FAQ

Does my 401(k) automatically end when I sell the company?

No. In a stock sale the plan generally stays with the company and becomes the buyer's plan after closing, unless it is terminated first. In an asset sale the buyer does not automatically take the plan. It may be terminated, as it was for one of my clients, and employees who move to the buyer generally become eligible to take a distribution or roll it over. Confirm which structure your deal uses with your attorney.

When does the termination need to happen in a stock sale?

Generally before closing, by board resolution. The successor plan rule looks at who the employer is on the termination date (Treas. Reg. 1.401(k)-1(d)(4)(i)). After closing, the buyer's 401(k) can count as an alternative plan and block termination distributions. Confirm the effective date with ERISA counsel.

What happens to unvested employer contributions?

On a full plan termination, the IRS requires affected participants to become 100% vested. In an asset sale where your plan continues, a 20% or greater turnover rate creates a rebuttable presumption of a partial termination, which also triggers full vesting for those who left. Your TPA can run the turnover numbers.

Can the buyer just merge my plan into theirs?

Yes, and sometimes that is the better outcome for employees. Keep in mind a merger brings your plan's history with it. If testing or deposit timing has problems, expect the buyer's counsel to ask for corrections, an indemnity, or termination before closing.

How early should I start looking at the plan?

A year before a sale is a reasonable floor. Corrections for late deposits and failed tests take time, and a termination distribution window generally runs 12 months on its own (IRS, updated 2026). Starting before you have a buyer keeps the plan off the list of things to negotiate.

Do you know right now whether your deal is likely to be a stock sale or an asset sale? That one answer decides most of what happens to the plan. Book a complimentary conversation and we can walk through the plan alongside the rest of your exit timeline.