I just moved from MA to CA this month.

Shall I file tax for both?

MA honor the treaty of 5000$ exemption. I'm F1 OPT from China.
What about CA?
Thanks

WindySnow:

If you earned income in Massachusetts and will earn income in California, then you must file state tax returns in each state.

Ideally, you will pay taxes to MA only on income earned in MA, and pay taxs to CA only on income earned in CA.

However, due to the complexity of both states' tax returns, I strongly recommend that you have a competent tax professional prepare these returns for you.