Do I file taxes in CA for all or part of my income?

[NotVeryTaxGal]

I work for a California employer and live in Washington state. However, I commute to my California office 3 days a week. Do I have to pay taxes for all of my income earned through a California employer? Or do I only pay California taxes for the income corresponding to the days I spent in California? 

Also, Am I considered a California Resident because I spend 3 work days in CA, and 2 work days +2 weekend days in WA? Even though I stay at hotels in CA, and my home is in WA.

[TomD8]

CA taxes non-residents only on CA-source income.  Income is "sourced" where the work is actually (physically) performed.  So you only have to pay CA income tax on the portion of your income earned by actually working in CA.

CA law considers a person to be a CA resident (for tax purposes) if that person "is in California for other than a temporary or transient purpose."  Since that's kind of vague, CA publishes a whole booklet on the issue of residency.  The examples on pages 4-5 should help you determine your status:  https://www.ftb.ca.gov/forms/2018/18_1031.pdf

[Lisa995]

You'll file a CA Non Resident return.  Your W2 should show the CA State Wages in Box 16,  it should be different than the amount in Box 1 of the W2.