Dependent Status

my 22 year old son wants to claim he supported himself in 2021 and not have me claim him as a dependent. since he was a full time student, his $12.5K in income plus his student loans contributed to more than 50% of his costs. Can he count his own student loan for that determination? His costs were probably ~$30K and counting his loans, he contributed ~$20K coupled with his earnings gross.