I get 1099 NEC income. Can I contribute to my 401k from this income?

Hi John,

A standard 401(k) is administered by an employer and you cannot make separate contributions to it. However, when you have self-employment reported on a 1099-NEC and file a Schedule C, you may contribute to a Solo 401(k).

https://www.irs.gov/retirement-plans/one-participant-401k-plans