I'd like to take advantage of a Solo 401k, but the maximum contribution language is a bit unclear to me.
Our situation:
1. I am employed, make most of the money in the household, and max out my company's 401k.
2. My wife works a few hours a week as a fitness instructor for 4 different gyms (they don't offer 401k plans). At a 5th, she is considered an independent contractor, where she makes about $2000 a year.
I usually make a maximum IRA contribution for her every year ($5.5K), but would a solo 401k allow me to contribute more? Is it capped at her business income ($2000) or at $18k if we consider joint income?