667 Area Code: Baltimore, Maryland

Maryland's 667 area code is an overlay covering the same eastern-half footprint long served by the 410 and 443. Baltimore anchors the directory's records here, set at the head of a deep natural harbor on the Patapsco River branch of the Chesapeake Bay. The 667 designation, part of the North American Numbering Plan, has been filling with allocations as eastern Maryland's number demand has continued to grow past what the older codes could support. The footprint extends across Annapolis, the Eastern Shore counties, and the surrounding region of central and eastern Maryland.

In records the directory has compiled for 667 numbers, Germantown — a city in western Maryland — appears regularly despite lying outside the 667 footprint. The pattern reflects standard public-record dynamics, with phone numbers porting across Maryland and addresses linked across multiple cities. The directory currently documents 32 distinct prefixes within 667 in detail, a working subset of the prefix population the code will eventually carry.

Baltimore's home values come in below the US median, with median household income running below the national figure. The city's median age sits close to the US reading, and population places Baltimore among the larger cities in the mid-Atlantic. The 667 footprint shares those demographics with 410 and 443 because all three codes serve the same broad geography in overlapping form, and the broader region's economic and demographic profile is more a function of the city itself than of any code-level distinction.