Yes, a 20 year old full-time student can be claimed as a qualifying child dependent. Living away at school is a "temporary absence" so you can say he lived with you all year and claim him as a dependent. You are the one who can use the education credit on your own return, too.
You say he had income from "gigs"----do you mean he had self-employment income? If so, he needs to file a tax return if he earned even $400 and pay self-employment tax for Social Security and Medicare.
MY DEPENDENT HAD A JOB
If your dependent has a W-2 for his after-school job, summer job, etc. you do not include the information on your own return. You can still claim your child as a dependent on your own return. He/she can file his own return for a refund of some of his withheld wages from boxes 2 or 17 (he won’t get back anything for Social Security or Medicare), but MUST indicate on it that he can be claimed as a dependent on someone else’s return. (Supervise this closely or prepare it for him!)
If your dependent’s earnings were over $400 and were reported on a 1099Misc or 1099NEC then he must file a return and pay self-employment tax for Social Security and Medicare.
You might also want to use free software from the IRS Free File versions:
https://apps.irs.gov/app/freeFile/
https://ttlc.intuit.com/community/self-employed/help/how-do-i-report-income-from-self-employment/00/...
https://ttlc.intuit.com/community/self-employed/help/what-is-the-self-employment-tax/00/25922
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
