Thanks. He graduated college in 2021, and has worked in 2022. A CPA friend had told me that we can claim him on our tax return, and he can file his own with zero exemptions (if it is the right word) - that seemed confusing to me in the sense would that reduce overall tax liability (we pay less in higher tax bracket, he pays more in lower tax bracket)? But it looks like that is not even an option since he earns way more than $4,400 per month.
