Solo 401 K Contribution Limits 2024. The irs maximum contribution to a solo 401k is $66,000 for 2023 (or $73,500 for those over age 50) and $69,000 for 2024 (or $76,500 for those over age 50). Here's how the 401(k) plan limits will change in 2024:

This amount is up modestly from 2023, when the individual. For 2023, the limits were.