One family, live in 2 states

[markc5]

We own homes in California and Oregon.  I would like to change my residence to Oregon while wife keeps the California address. We have kids finishing up school and we will move permanently in 2028, but would like to transition over time.  What challenges would we have with me (retired) in Oregon and her (full-time employee) in California?

[TomD8]

If you're not going to permanently move to Oregon until 2028, then generally speaking you will remain residents of California for tax purposes until that time.  You can't just pick and choose your state of residency for tax purposes; you must follow state law.  You should familiarize yourself with California's rules on residency, which are explained in detail in this tax publication:

https://www.ftb.ca.gov/forms/2023/2023-1031-publication.pdf

CA law is that you remain a resident of CA until you abandon your domicile in CA and establish it in another state.  See page 10 of the above-cited reference for more detail.