How Does an RSU Vesting Schedule Compare to a 401(k) Vesting Schedule?
Two of the most common pieces of a compensation package — company stock grants and a retirement plan’s employer contributions — both use the word “vesting,” and both make an employee wait before fully owning something. Past that shared vocabulary, though, the rules behind each come from entirely different places.
The short answer
An RSU vesting schedule is set by the individual equity grant agreement between employer and employee and can follow almost any structure the company chooses, while a 401(k) vesting schedule for employer contributions has to follow specific timing limits established by federal pension law. The two also differ sharply in how they’re taxed once vested. They look similar on the surface — both delay full ownership of something — but they operate under different rules for different reasons.
Where each schedule actually comes from
An RSU’s vesting terms live entirely in the grant agreement a company offers, and there’s no federal law dictating how long that schedule has to be or what shape it has to take. A company might use a single cliff after a set number of years, a gradual schedule that vests a portion each year or quarter, or some hybrid the company designs on its own. A 401(k)’s vesting schedule works differently: it applies specifically to employer contributions like a match or profit sharing, and federal pension law sets maximum allowable timelines for how long a plan can delay full ownership, whether structured as a single cliff or a graded schedule spread across several years. That ceiling exists to protect employees from open-ended waiting periods on money their employer has already contributed on their behalf.
Why the tax treatment diverges even further
RSUs are taxed as ordinary income based on the fair market value of the shares at the moment they vest, regardless of whether the shares are sold right away or held. There’s no tax-advantaged wrapper involved — the value simply counts as compensation the year it vests. Employer contributions to a 401(k), by contrast, aren’t taxed as income when they vest; they grow inside the retirement account on a tax-deferred or, in a Roth arrangement, potentially tax-free basis, with taxation generally deferred until money is withdrawn from the plan. Vesting in the retirement account sense is about ownership, not a taxable event on its own.
What leaving a job does to each
Unvested RSUs are typically forfeited entirely if an employee departs before the vesting date, with no partial credit for time already worked toward that grant. Unvested employer 401(k) contributions generally work the same way — forfeited if someone leaves before reaching the plan’s vesting threshold — though it’s worth remembering an employee’s own contributions to a 401(k) are always fully owned from the moment they’re made, regardless of vesting schedules that apply only to the employer’s side.
Why the comparison is still useful
Even though the two systems answer to different rules, thinking of both in terms of what percentage of a benefit is actually owned right now, and when that changes, is a genuinely useful lens when evaluating a job offer or a total compensation package. Other equity-adjacent benefits, like the offering period in an employee stock purchase plan, add yet another timeline with its own separate logic, which is part of why total compensation can be harder to compare across employers than a base salary figure alone.
The bottom line
RSU vesting and 401(k) vesting share a word and a general concept — delayed full ownership — but different bodies of rules, different flexibility for the employer, and different tax consequences once vesting happens. Understanding which rules apply to which benefit makes it much easier to read an offer letter or benefits summary accurately.