State of residency when living with grandparents

Parents live in one state and grandparents live in another. Attends school in grandparents state but one of the parents will complete FAFSA. Which state for instate tuition?

It depends on the state(s). The state where the student graduates from high school MAY give instate tuition. The state where the parents are legal residents MAY (probably will) give instate rates to a resident’s child (this would be common for a boarding school student, ex). It may be that both states will give instate rates. It may be that neither will.

Colorado gives instate rates to a child if a parent lives in the state. Child doesn’t have to live there, the parent doesn’t have to take the child as a tax dependent. My nephew got instate rates in Colorado and he went to high school in Florida and his mother (FL) claimed him as a dependent.

In the very vast majority of cases, undergrad student residency is based on where the student’s parents reside.

What states are you talking about? Perhaps someone here will be able to link the residency for instate tuition requirements.