401(k) Vesting

Vesting is the process by which employer 401(k) contributions become the employee's property on a schedule. The employee's own deferrals are 100% vested by law from the first dollar. Only the employer match and profit-sharing contributions follow a schedule, and federal rules cap how slow it can run: a 3-year cliff, where nothing vests until the third anniversary, or graded vesting from 20% at two years to 100% at six.

Safe-harbor plans, the most common match designs, vest employer contributions immediately, which is why job-hoppers sometimes keep matches they assumed they would forfeit. Service is measured in hours worked, generally 1,000 per year. SECURE 2.0 now counts long-term part-time employees toward eligibility and vesting after two consecutive years of 500-plus hours.

The schedule runs on years of service, counted as plan years in which you log at least 1,000 hours. On a 3-year cliff, an employee who leaves at 34 months is 0% vested in the match; the same employee at 36 months is 100%. On the 2-to-6 graded schedule, 20% vests at the end of year two and another 20% each year after, so a four-year employee owns 40% of the match and forfeits the remaining 60% at separation. Employers choose between the two maximums, or adopt faster tables; slower ones are not permitted.

Separation is the trigger, and the forfeited slice returns to the plan, where it pays expenses or reallocates to other participants. Deferrals never follow this logic: they are vested the day they land. Employers may adopt faster schedules, and safe-harbor designs must vest immediately for employer contributions. A returning employee often gets prior service credited if the break is under five years, which restores part of the forfeited schedule.

Vesting also matters at retirement: a fully vested balance rolls to an IRA cleanly, while unvested employer money is simply gone. The match is compensation contingent on staying, and the schedule is the contract's fine print.

At a typical match of 50% on the first 6% of an $80,000 salary, the match is $2,400 a year, and the vesting schedule decides how much of three years' worth you keep. On a cliff schedule that is $7,200 plus growth; on a graded schedule, a sliding share. The amounts are real money, and they sit entirely inside the fine print most employees never read.

I watched a colleague named Brent (yes, that Brent) resign at month 34 of a 3-year cliff, one resignation letter ahead of $7,600 of vested match and growth. He called the move decisive; the plan called it a forfeiture, and the forfeited slice went to paying plan expenses. The timing, not the decision, was the mistake.

The highest-leverage thing most employees can do is read the vesting schedule before signing anything, whether an offer or a resignation, and check whether the plan is safe harbor. Size the match against your plan with the retirement savings calculator and project the career cost of a jump with the investment calculator.