Unless you are in the military, you become a CA resident once you have moved to CA. You could still be considered a non-resident if your job has transferred you to CA for a temporary period of time. Once you have earnings in CA, you will have to file a tax return and be taxed on those earnings. If it’s a split year (ie earnings in both NM and CA), your CA tax return is pro-rated and, if NM has State tax (which it does!), you will need to file both States tax returns. You will get a credit for taxes paid to NM so that you are not paying taxes on the same money twice. This is probably the year you should consult an Enrolled Agent, the only federally licensed tax professional!