What are the Solo 401(k) contribution limits?

There are two separate allowable contribution types. For 2022 the employee contribution is limited to 100% of the first $20,500 of income. For business owners over the age of 50 there is an additional $6,500 ‘catch-up’ contribution for a total of $27,000. In 2023 the contribution limit is $22,500 with a $7,500 catch-up contribution for owners 50 and over for a total of $30,000. The employer contribution is limited to 25% of W-2 compensation if the business is incorporated or 20% of self-employment income if the business is a sole proprietorship. The business owner has contribution flexibility in that, each year, he can choose whether to make the employer contribution. Total plan contribution limits, not counting catch-up contributions for those age 50 and over, cannot exceed $61,000 for 2022 and $66,000 for 2023.