What is the postal abbreviation for Maryland?

The postal abbreviation of the state of Maryland is MD. Until 1963 the Post Office Department preferred that state and territorial names be written out in full to avoid confusion, but accepted the popular public practice of abbreviation.

The Department published lists of preferred state abbreviations in the 1831 Table of Post Offices in the United States and in the United States Official Postal Guide, first published in 1874. Most of the preferred abbreviations in 1874 remained the same for nearly the next 90 years.

Maryland is a state in the Mid-Atlantic region of the United States.The state's largest city is Baltimore, and its capital is Annapolis. Among its occasional nicknames are Old Line State, the Free State, and the Chesapeake Bay State. It is named after the English queen Henrietta Maria, known in England as Queen Mary.