It depends. Two reasons to file a CA tax return even if you don't owe any CA taxes; you meet the requirements to file based on your residency status, filing status and income level or to get a refund.
Here is a link to the filing requirements for CA. On that CA landing page click the "Resident" link if you lived in CA all year or the "Part-year, Non-resident" link if you did not live in CA for at least part of the year. There you find the requirements per your residency status.
Finally, if you are due a CA refund you need to file to get that.
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