Carl
Level 15

Education

My son filed a 1040EZ form for his 2018 taxes.

No, he filed a 1040. Effective with the 2018 taxes the 1040-EZ and 1040-A no longer exist.

Can I still claim him as a dependent for his college expenses in 2018 if I itemized my return?

Weather or not your son filed a tax return, and weather or not you itemize has absolutely nothing to do with you claiming him as your dependent. It also doesn't matter how much he earned either. He could have earned a million dollars (literally!) and still qualify as your dependent.
Take special note of the below. There is *no requirement* for the parent to provide the student any support. Not one single penny. The support requirement is on the student, and only the student. That requirement is:
If the *STUDENT* did *NOT* provide more than half of *THEIR OWN SUPPORT* for the tax year, then the parents qualify to claim the student as a dependent on the parent's tax return.
There are only two possible ways the student can provide more than half of their own support.
 - The student is the *PRIMARY* borrower on a qualified student loan and sufficient funds were distributed to the student during the tax year for the student to provide more than half of their own support.
 - The student had a W-2 job or was self-employed and made enough money during the tax year to have provided more than half of their own support.
Scholarships, grants, 529 distributions, gifts from Aunt Mary, money from mom and dad, etc.  *do* *not* *count* for the student providing their own support.
Additionally, the costs must be realistic. For example, if the student received $80,000 in grants, scholarships and 529 distributions and earned $500,000 in the same tax year, then the overall cost of support (including education expenses) would have to exceed $160,000 for the student to claim they provided more than half of their own support. ($80K from the third party sources, and more than $80K from what the student earned.) Now there is no way on this green earth that "support" for an undergraduate student will exceed $160,000 for a single tax year. Just not gonna happen even if attending Harvard Law School, Yale, or BYU. So even though the student earned enough during the tax year, with $80K in third party support it's not feasible or even realistic that he paid in excess of an additional $80K of his own $500K of earned income to support himself.