When your company is acquired, your 401(k) is generally protected, the buyer either continues the existing plan, merges it with theirs, or distributes it to participants. Pensions are more complex: they may be frozen, terminated, or assumed by the acquirer. Vested equity typically accelerates or rolls into the buyer's stock. The most consequential decisions you'll need to make involve deferred compensation and unvested equity, review the merger terms before you have to act.
401(k) plans are protected by ERISA, and acquisitions don't change your vested account balance. The acquirer has three common options: (1) maintain your existing 401(k) as a separate plan; (2) merge it into the acquirer's 401(k), which may change investment options and fees; or (3) terminate the plan, in which case participants can roll the balance to an IRA or to the acquirer's plan. Vested company match dollars can't be taken away. Unvested matches may be accelerated to fully vested at the merger close, check the merger documents.
Pensions are more vulnerable. A defined benefit pension may be frozen (no further accruals, but existing benefits preserved), terminated and replaced with a lump sum or annuity, or assumed by the acquirer with continued accrual. If the pension is frozen, the benefit you've already earned is locked in but no longer grows with future service. If the pension is terminated and you're offered a lump sum vs lifetime annuity, the choice is consequential and irreversible, see our deeper analysis on pension lump sum vs annuity.
Equity compensation often accelerates at acquisition. Unvested RSUs, stock options, and performance shares typically receive 'change of control' acceleration, either fully or partially, depending on plan terms and individual award agreements. The tax consequences can be significant, a large slug of RSUs vesting in a single year can spike your taxable income, push you into higher brackets, and trigger AMT exposure. If acceleration is coming, planning around it should start before the close, not after.
Nonqualified deferred compensation (NQDC) is the most underestimated risk. Unlike 401(k) balances, NQDC is an unsecured promise from the company, meaning it's at risk in bankruptcy and treated as a general creditor claim. Acquisitions don't typically trigger payout, but the acquirer may amend the plan, change investment options, or alter distribution timing. If the acquirer is financially weaker than your current employer, your NQDC has just become riskier. Review the deferral elections and consider whether an in-service distribution (if available) makes sense.
Key facts
- 401(k) vested balance is protected, can't be reduced by acquisition
- Unvested employer match: often accelerates to full vesting at change of control (check plan terms)
- Pensions: may be frozen, terminated, or assumed by acquirer, outcome varies by deal
- RSUs and options: often subject to 'change of control' acceleration, can spike taxable income
- Nonqualified deferred compensation (NQDC): unsecured creditor claim, risk profile may change at acquisition
- PBGC: federal pension insurer that protects most defined benefit pensions if employer becomes insolvent (with benefit caps)
Should I take the pension lump sum if my company is acquired?
It depends on the lump sum's actuarial value vs the lifetime annuity, your other guaranteed income sources, and your life expectancy. Lump sums are typically calculated using IRS-mandated discount rates that have varied dramatically over the past 5 years, when rates rise, lump sums fall. Most pensions are protected by PBGC if the acquirer fails, providing additional security to the annuity option. The annuity is also a non-portfolio asset that doesn't carry market risk. We model both options against your full retirement plan before recommending, there's no universal right answer.
What happens to my unvested stock options at an acquisition?
It depends on the merger agreement and your award terms. Common treatments: (1) full acceleration, all unvested shares vest at close; (2) partial acceleration, a portion vests, the rest are forfeited or converted to acquirer equity; (3) assumption, the acquirer rolls your options into equivalent options on their stock; (4) cash-out, options are paid out at the deal price minus strike price. The tax consequences differ for each. ISOs converted in a deal may lose their incentive treatment if not handled correctly. Get the merger terms in writing and run the tax analysis before any of your equity vests.
