Q. So, if I understand the link you sent correctly, with my filing status "Married/RDP filing jointly no dependents, both are under 65" my threshold is $38,624 of Salary earned while I am in California?
A. No. Your filing threshold is $38,624 of total income, regardless of where earned. But, as others have said, CA will only tax the income earned in CA, not your total income.
Q. I sometimes travel to and work in other states. Am I required to file taxes and pay tax to those states.?
A. Yes, but almost "nobody" does. But you should.
See http://money.cnn.com/2013/06/28/pf/taxes/business-traveler-tax-threat/ If you live in a state without an income tax (e.g. FL or TX), it’s more likely you should file in the work states. You can't use the "it all comes out even" rationale for not filing.
