You will have to prepare and file a non-resident/part-year resident MD tax return, in addition to your CA resident/part-year resident return.
In the state income allocation interviews, you will allocate all of your income to CA, and none to MD. This should result in a full refund of the MD tax withheld.
(You might want to file the MD return first, in order to use the MD refund to pay your CA tax).
