Yes, Cortez can file as head of household if his 20-year-old son is a full-time student because he met some certain requirements as a taxpayer.
What are the requirements?
The taxpayer must be single or considered unmarried by the last day of the tax year. This includes being divorced, legally separated, or living apart from their spouse for the entire year.
The taxpayer must provide more than half the cost of maintaining a household for themselves and at least one qualifying person. This can include rent, mortgage payments, utilities, groceries, and other household expenses.
In conclusion, we can say that Cortez can file as head of household if he pays more than half the cost of maintaining a household for himself and his son, and his son is a full-time student.