Dependent or not ?

My 22 yr old son took the fall semester off in 2019.  He was working and made $20,000.  Can I claim him as a dependent this year ?  Should I be claiming him as a dependent since he made $20,000?  (FYI, he has no student loans.... I also have an 18 yr old who started college fall of 2019 and will be claiming him as a dependent.) 

I'm just not sure what to do this year, please help !

Thanks