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Master Address Repository

The MAR is a database of building addresses, blocks, intersections, place names and other location identifiers in the District. The MAR allows the District government to more easily compare and relate information with locations across databases and agencies.   Each address in the MAR is standardized and assigned a unique Address Identification Number (AID), map coordinates and other useful information.

The DC Location Search is part of the MAR. It makes locating addresses as easy as possible by employing spell check and lists of street names and street type “aliases.” For Example Martin Luther King Jr Avenue is also referred to as MLK Ave.  In addition to locating addresses, the MAR also helps users find intersections, blocks, place names and condo/apartment units.

MAR Web Services are built and distributed using DC’s service-oriented architecture. The MAR  Location Search is built from two SOAP web services:  the MAR service and the BasicMap service. This makes it easy for DC agencies to embed standard address and spatial searching into their applications and web sites.


Service Contact: 
Contact Email: 
Contact Phone: 
(202) 724-5135
Contact TTY: 
Contact Suite #: 
5th Floor
Office Hours: 
Monday to Friday, 9 am to 5 pm
Service Location: 

200 I Street, SE

GIS Address: 
200 I Street, SE