The 339 area code is an integral part of Massachusetts' telecommunications system, particularly in the greater Boston area.

Introduction as an Overlay: The 339 area code was introduced as an overlay to the existing 781 area code. This implementation, effective on May 2, 2001, was designed to provide additional numbering resources in response to the high demand for telephone numbers in the greater Boston area. The overlay approach allowed existing 781 subscribers to keep their phone numbers, while new numbers could be assigned the 339 area code.

Geographical Coverage: The 339 area code, along with the 781 area code, covers a significant portion of the suburbs surrounding Boston, including cities and towns like Lynn, Waltham, and Medford. The area represents a mix of urban and suburban landscapes, reflecting the diverse demographic and economic composition of the region.

Adoption of Ten-Digit Dialing: With the introduction of the 339 overlay, ten-digit dialing (area code + phone number) became mandatory for all local calls within the 781 and 339 area codes. This requirement, aligning with the standard practice in regions with overlay area codes across the United States, was essential to manage the growing number of phone users and the consequent need for more telephone numbers in the region.

These facts about the 339 area code highlight its vital role in supporting the telecommunications needs of the suburbs surrounding Boston. By providing additional numbering capacity and facilitating the transition to ten-digit dialing, the 339 area code ensures that the region's communication infrastructure can keep pace with its growth and evolving needs.