You probably have a more important question than the one you asked; the answer to which will answer the question you did ask.
Q. Can your dad claim you as a dependent for 2023?
A. No.
There are two types of dependents, "Qualifying Children"(QC) and Other ("Qualifying Relative" in IRS parlance even though they don't have to actually be related). You can't be a qualifying relative because you have too much income. There is no income limit for a QC but there is an age limit, student status, a relationship test and residence test.
A child of a taxpayer can still be a “Qualifying Child” (QC) dependent, regardless of his/her income, if:
- He is under age 19, or under 24 if a full time student for at least 5 months of the year, or is totally & permanently disabled. Graduating in May meets this requirement.
- He did not provide more than 1/2 his own support. Scholarships are excluded from the support calculation. This is iffy, in your case.
- He lived with the parent (including temporary absences such as away at school) for more than half the year. When you graduated in May, and took a job in MA, your temporary off campus college housing became your permanent residence and you ceased being considered as still living with your parent. You don't meet the more than half the year rule. So, you can't be his dependent.
Prior to May, an argument could be made that you were still a PA resident (you were still a student away at college) and you should file as a part year resident of both states.
Q. Is it worth to file as a PA resident still?
A. No. The only reason was to establish that you were living with your Dad so he could claim you as a dependent. In you circumstances, the stronger argument is that you were a MA resident all year.
