Solo 401(k)
401(k) retirement plan covering only a self-employed business owner and optionally their spouse.
Definition
A Solo 401(k), also called Individual 401(k), Self-Employed 401(k), or Uni-K, is a qualified retirement plan adopted by an unincorporated sole proprietor, single-member LLC, S-corp owner, or partnership where the only employees are the owner(s) and their spouse(s). It allows both employee deferral (up to $23,500 in 2025, $31,000 if age 50+) and employer profit-sharing contribution (up to 25% of compensation).