The Qualifying Child rules for a dependent. you seem to meet them. The only question is if he earned enough to qualify to having provided more than half his own support.
Relationship YES he is your son and I assume he is a US citizen.SupportYour child may have a job, but that job cannot provide more than half of her support. Te see if he may have fill out this https://apps.irs.gov/app/vita/content/globalmedia/teacher/worksheet_for_determining_support_4012.pdf
Residency Child must live with you (or your spouse if you file a joint return) in the United States4 for more than half of the year. You said he lived with you more than 6 months.SUPPORT TEST LINK <a rel="nofollow" target="_blank" href="https://apps.irs.gov/app/vita/content/globalmedia/teacher/worksheet_for_determining_support_4012.pdf">https://apps.irs.gov/app/vita/content/globalmedia/teacher/worksheet_for_determining_support_4012.pdf</a>
@maglib Looks like we are viewing this differently. The child was a 17 year old full-time student in 2017--not subject to the $4050 income criteria.
@xmasbaby0 He is subject to the child could not have provided over half his own support though...
@kmackison if you can legally claim him, he can NOT claim himself and he will have to fill out his return saying that someone else claimed him. The support test is not based on calendar, it's based on all costs so that would be the only reason he can claim himself vs. you as
<a rel="nofollow" target="_blank" href="https://www.irs.gov/help/ita/whom-may-i-claim-as-a-dependent">https://www.irs.gov/help/ita/whom-may-i-claim-as-a-dependent</a> IRS dependent calculator if needed.
He is still your dependent.
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 (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 then he must file a return and pay self-employment tax for Social Security and Medicare. You may want to use this version of TT for that: