939 Area Code: San Juan, Puerto Rico

Puerto Rico's 939 area code is an overlay sharing geography with the long-running 787 across the entire territory. San Juan, the territorial capital and largest city, anchors the directory's records here. San Juan sits on the northern coast of Puerto Rico, organized around the historic core of Old San Juan and the broader modern city that extends along the coast and inland into the surrounding municipalities. The 939 designation, part of the North American Numbering Plan, has been filling with allocations as Puerto Rico's number demand has continued to grow past what 787 alone could carry.

Because 939 covers Puerto Rico in its entirety alongside 787, the directory's records associated with 939 numbers do not surface a recurring set of secondary cities through the standard cross-state linkage patterns that dominate larger codes. Where other-place names do appear, they reflect the same kinds of public-record dynamics seen elsewhere — numbers porting between carriers, addresses tied to multiple residences, and prior registrations surfacing alongside current ones. The directory currently documents 102 distinct prefixes within 939 in detail, a working subset of the prefix population the code carries.

San Juan's median age sits notably above the US figure, in the mid-forties. Median household income runs dramatically below the national reading. Home values come in below the US median, and population places San Juan as the largest city in Puerto Rico. The 939 footprint shares those demographics with 787 because both codes serve the entire territory in overlapping form.