@jowie2monte - it depends.... how much did he make? was he a full time student the first part of the year? did you provide more than half of his support in 2020?
it's possible he is your dependent and your son filed incorrectly OR he filed correctly and your son is no longer your dependent. THere are simply a lot of variables
do me a favor, take 5 minutes and go through this IRS tool and just answer the questions, it will guide you to the correct answer
https://www.irs.gov/help/ita/whom-may-i-claim-as-a-dependent
