Telephone Area Codes

Maryland Telephone Area Code Boundaries represents the telephone area codes for the State of Maryland. They are also known as Numbering Plan Areas (NPA). The Numbering Plan Areas reflect current and accurate boundary changes both where new NPAs split from existing NPAs and where new NPAs overlay existing NPAs. When an NPA is split, the geographic area covered by the old area code is divided geographically, with one portion retaining the previous area code and the other switching to the new area code. When a new NPA is added as an overlay, the old area code remains unaffected. Instead, all or part of the land covered by the old area code is now covered by the old and new area codes.

Data and Resources

Field Value
accessLevel public
catalog_@context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
catalog_@id https://opendata.maryland.gov/data.json
catalog_conformsTo https://project-open-data.cio.gov/v1.1/schema
catalog_describedBy https://project-open-data.cio.gov/v1.1/schema/catalog.json
identifier https://opendata.maryland.gov/api/views/smyu-49g4
issued 2025-07-22
landingPage https://opendata.maryland.gov/d/smyu-49g4
modified 2025-08-21
publisher opendata.maryland.gov
resource-type Dataset
source_datajson_identifier true
source_hash 94fe1787b128b47154e99f559f55bf437f91d4527281a3871d578a04552bba74
source_schema_version 1.1
Groups
  • AmeriGEOSS
  • National Provider
  • North America
Tags
  • AmeriGEO
  • AmeriGEOSS
  • CKAN
  • GEO
  • GEOSS
  • National
  • North America
  • United States
isopen False
license_id notspecified
license_title License not specified
maintainer J.B. Churchill
maintainer_email no-reply@opendata.maryland.gov
metadata_created 2025-09-23T14:46:49.423139
metadata_modified 2025-09-23T14:46:49.423145
notes Maryland Telephone Area Code Boundaries represents the telephone area codes for the State of Maryland. They are also known as Numbering Plan Areas (NPA). The Numbering Plan Areas reflect current and accurate boundary changes both where new NPAs split from existing NPAs and where new NPAs overlay existing NPAs. When an NPA is split, the geographic area covered by the old area code is divided geographically, with one portion retaining the previous area code and the other switching to the new area code. When a new NPA is added as an overlay, the old area code remains unaffected. Instead, all or part of the land covered by the old area code is now covered by the old and new area codes.
num_resources 4
num_tags 8
title Telephone Area Codes