Buy a Local Phone Number – Area Code 301 (Rockville, Maryland)

From its 1947 debut covering all of Maryland, area code 301 mirrored the state’s postwar growth and suburbanization around Washington, D.C. A 1991 split created 410 for Baltimore and the Eastern Shore, concentrating the code in western and suburban counties. Overlay 240 arrived in 1997, followed by 227 in 2023, cementing ten‑digit dialing across the region that includes Rockville, Gaithersburg, Frederick, and the southern Maryland peninsulas.

Rockville sits at the heart of the I‑270 Technology Corridor, where federal science campuses, laboratories, and contractors anchor a research‑driven economy. Nearby assets include NIST in Gaithersburg, NIH in Bethesda, Fort Detrick’s biodefense complex in Frederick, and the FDA’s White Oak campus; farther south, NAS Patuxent River supports naval aviation R&D and testing. The corridor’s growth has fostered a diverse, highly educated workforce, commuter rail and Metro‑linked communities, and an entrepreneurial ecosystem in life sciences, cybersecurity, and geospatial analytics, while western counties retain manufacturing, logistics, and outdoor recreation identities.

• Life sciences and biotechnology
• Federal agencies and contractors
• Defense and aerospace, naval aviation
• Cybersecurity and cloud/IT services
• Advanced manufacturing and logistics