If you have recently moved to California and have placed insurance on your vehicle you should be able to maintain that insurance with an out of state license until you are able to acquire a CA driver's license. This should be done rather quickly if you are now a California resident.
If you take a job in CA or become a resident, you must get a California driver license within 10 days. Residency is established by voting in a California election, paying resident tuition, filing for a homeowner's property tax exemption, or any other privilege or benefit not ordinarily extended to nonresidents.
As a resident of California you will need to acquire a California driver's license as well as register your car in state with the CA DMV. Residents of other states may operate their vehicles with current registration in their names from their residence state for up to six months or until they:
- Accept gainful employment in California or become a California resident.
- Claim a homeowner's exemption in California.
- Rent or lease a residence in California.
- Enroll in an institution of higher learning as a California resident or enroll their dependents in school (K-12).
- Intend to live or be located here on a permanent basis (e.g., acquire a California driver license, acquire other licenses not ordinarily extended to a nonresident, registered to vote, etc.).
Fees must be paid within 20 days of entry or residency to avoid penalties.
It is illegal to drive with an invalid license in California, which an expired one is. If you have an expired license you should try to get it renewed or get a California license as soon as possible so that you are not cited by law enforcement.
If your insurance would still be in force with your license being expired will depend upon your insurance company's guidelines and the terms of you policy. There may be an exclusion that disallows coverage if you have an expired or invalid license. Check with your insurance agent to find out for certain how they deal with this situation.