to better answer your question and t properly advise you on any filing requirements that the dependent may have. what was their age on 12/31/2021. it is also necessary to determine if the dependent is a qualifying child or qualifying relative,
this affects their tax reporting, your tax reporting, possible kiddie tax and properly completing form 8962
you can claim them as a qualifying child if all these tests are met
• they have the same principal abode as you for more than ½ the tax year. Temporary absences like for school are ignored
• if they are not a full-time student, they are under 19 at the end of the tax year. If a full-time student, they are under 24 at the end of the tax year.
• they hasn't provided over ½ their own support
• they didn't file a joint return unless there was no tax liability but merely filing jointly to facilitate refund of taxes withheld or estimates paid
or you can claim them as a qualifying relative if all these tests are met
• their gross income for 2021 is less than $4,300 (this includes capital gains but not capital losses)
• you provided over ½ their support
• they aren't a qualifying child of another taxpayer
