Solo 401(k)

A 401(k) plan designed for self-employed individuals or business owners with no employees other than themselves (and a spouse). Allows both employee deferrals and employer contributions, with a combined limit of up to $72,000 in 2026 ($80,000 with the age-50+ catch-up, $83,250 for ages 60–63). Higher contribution potential than a SEP-IRA for many self-employed individuals. Not available to partners in a partnership.