Generally the rule is 60 days of actual living in the state with some type of proof of that. A piece of mail to a p.The Maryland MVA's 'sources of proof' page lists these as proof of Maryland residency; at least two are required. Required Residency Documentation for ID: Two proofs of Maryland residency required (must include full name and residential address; must be from two different. Have a PO Box address; or; Hold a commercial driver's license (CDL); or; Represent a company. Registration card; Maryland Certificate of Title. Ones address has NOTHING to do at all do with where one lives, UNLESS the DIRECTION in which one receives their MAIL to be sent, is also their abode. Post Office Box™ (PO Box™) Service Requires a Secondary ID to show physical address for establishing services. ✓. ✓. ✓. ✓. ✓. ✓. Note: Source documents (two required) must be original and contain a valid DC address (PO boxes not acceptable).