Form 5500 & Code 3B

Code 3b - Use this code if the plan covered self-employed individuals in the return year.  Does this mean if someone was a Schedule C or K1 employee (not w2) in the Plan?  Thank you.

That is correct. Someone with Schedule C income, partner in a partnership (receiving a K-1).

btw, Happy Birthday

Earned Income vs W-2 Pay.  Typically called Owner-Employee in plan documents.  Just my 2 cents.