Who publishes Telephone Area Codes?

Maryland Department of Information Technology, part of State of Maryland, publishes this dataset on Maryland Open Data.

How often is it updated?

The publisher lists the update frequency as as needed. The last update was on 07/22/2025.

How do I download it?

It is available as CSV, JSON, GeoJSON, XML. Use the links in Files and access, which open the official government source.

Something wrong? Let us know

Checked Oct 31, 2026

State dataMaps & Geospatial

Telephone Area Codes

Name: Telephone Area Codes
Creator: State of Maryland
Published: 2025-07-22T02:29:34.000Z

Published by Maryland Department of Information Technology · Updated 07/22/2025 · As needed

Official source Download CSV

Last updated: 07/22/2025; First published 07/22/2025
Update frequency: As needed
Formats: 4; CSV, JSON, GeoJSON
Coverage: Maryland; Statewide

About this dataset

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.

Files and access

Links open the official government source

CSV downloadopendata.maryland.govCSV
JSON (SODA API)opendata.maryland.govJSON
GeoJSONopendata.maryland.govGeoJSON
XMLopendata.maryland.govXML

API endpoint: https://opendata.maryland.gov/resource/smyu-49g4.json

Links open outside websites we do not control.

Frequently asked questions

Who publishes Telephone Area Codes?: Maryland Department of Information Technology, part of State of Maryland, publishes this dataset on Maryland Open Data.
How often is it updated?: The publisher lists the update frequency as as needed. The last update was on 07/22/2025.
How do I download it?: It is available as CSV, JSON, GeoJSON, XML. Use the links in Files and access, which open the official government source.

Where this catalog comes from

Data.gov CatalogU.S. General Services Administration
State and local open data portalsSocrata Discovery API
State and city CKAN portalsCalifornia, Virginia, Boston, Houston and more
Government ArcGIS Hub sitesCity and county GIS data

Catalog checked 10/24/2026

We list dataset descriptions only. Downloads and APIs link straight to the official government source, which holds the current version and its terms of use.

Source: Maryland Open Data and Data.gov · Last updated 10/24/2026 · Listing only; the data stays with the publisher