401(a) vs 401(k): What's the Difference?

A 401(a) plan is an employer-sponsored defined contribution plan that allows employer contributions, employee contributions, or both. Government employers and some nonprofits use 401(a) plans because they offer flexibility in how contributions are structured — the employer can set different contribution amounts for different employee groups, make contributions mandatory or voluntary, and choose whether to allow employee deferrals.

A 401(k) is technically a specific type of 401(a) plan — one that includes a qualified cash or deferred arrangement (CODA), meaning employees can choose to defer salary into the plan. A standalone 401(a) plan typically does not allow employee salary deferrals; instead, the employer may make contributions on the employee's behalf. Governmental 401(a) plans are common for state and municipal employees.

State and local government employees, university faculty, and some hospital workers commonly have 401(a) plans. If you work for a public university, you may have a 401(a) for employer contributions alongside a 403(b) or 457(b) for your own salary deferrals. The 401(a) gives the employer control over contribution amounts and vesting schedules, while the 403(b) or 457(b) lets you control your own contributions.

If you leave an employer with a 401(a), you can typically roll the balance into an IRA or a new employer's qualified plan, depending on the plan's rules. Governmental 401(a) plans often allow rollovers to IRAs. Check with both plan administrators to confirm what transfers are permitted. Unlike a 401(k), you generally cannot take a loan from a 401(a) unless the plan specifically allows it.

A 403(b) is specifically for tax-exempt organizations and public education. A 401(a) can be offered by government employers more broadly. Some public-sector employees may have both a 401(a) (for employer contributions) and a 457(b) (for their own salary deferrals).