
The Mega Backdoor Roth for the Self-Employed: How a Solo 401(k) Reaches $72,000 in 2026
A Solo 401(k) with voluntary after-tax contributions lets self-employed owners shelter up to $72,000 in 2026 — or $83,250 with the age-60-to-63 catch-up — by converting after-tax dollars to Roth with no income limits. Here's how the three contribution buckets work, a worked example at $150,000 of net earnings, and what your plan document must allow.










