I'm a house wife so I have zero income, my husband works and lives in Colorado, I have been in Arizona since December 2016 caring for my grandmother, so technically I'm an Arizona citizen but no earne

[DS30 · Accepted solution]

No - you will not be considered an AZ resident unless you actively try to change your residency to AZ (change driver's license, voters registration etc.)

The fact that you are being a kind grandchild and taking care of your grandmother will be considered only a temporary relocation even if it is for more than a year.

Therefore, you will remain a resident of CO, if that was your original state of residency before you went to take care of your grandmother.

[Carl]

There's also no reason why you would not file joint with your husband either. It's also possible that your grandmother might qualify as a relative dependent on your joint tax return too. Might be worth checking out.