Question: I plan on applying to a California State university and I have grandparents living in California. I would like to use their address to apply as it would lower my tuition costs, but I currently live in Colorado. Will I be able to use my grandparents address in my application?

Definitely NOT!! Half of the high school students in the US would be heading to the Left Coast to bunk with Grandma or Grandpa, Aunt Edna or Uncle Earl, if the enticing (and outstanding) California colleges and universities allowed applicants to use their relatives' addresses ... or didn't check carefully when applicant and high school zip codes are miles apart.

Here is a summary of CA residency requirements for tuition purposes:

To be considered a California resident for purposes of fees, an out-of-state student must have lived in California for more than one year preceding the residence determination date, relinquish residence in other states, show an intent to establish residency in California and demonstrate financial independence. Unmarried undergraduates from other states qualify as financially independent if they were not claimed by their parents or others as dependents for tax purposes for two preceding tax years and if their annual income is sufficient to meet their needs.

So, in order to attend a CA school as a resident, you would have to move in with your grandparents (or elsewhere in the Golden State) for two years for a purpose other than attending school. (Although there is officially only a one-year residency requirement, it takes two years for most students who have been named as dependents on parental tax forms through high school.) In other words, you would have to get a job and not only earn wages in CA but also be able to prove that you are self-supporting and no longer financially linked to your parents in Colorado. They couldn't declare you as a dependent on their taxes; you would have to change your driver's license (if you have one), your library card, and any other documentation that connects you to your current home.

I know it can be frustrating to pay high out-of-state tuition when one has ties to that state, but the rules are very strict and carefully scrutinized to protect the true residents. So I'm afraid you'll have to rethink your plan.