Charlestown, MA

ZIP code 02129 is assigned to Charlestown, MA, and falls within Suffolk County. Like every US postal code, it began as a mail-routing device rather than a geographic boundary — the US Postal Service groups delivery routes under a single code so carriers and sorting equipment can process mail efficiently. Today it also serves as a practical shorthand for the area itself: roughly 19,994 people live inside it.

At 14,778 residents per square mile spread over 1.353 square miles, 02129 reads as a dense urban area. It is a mid-sized postal code by population, and density shapes almost everything else on this page — how people get to work, whether they own or rent, and what housing costs.

Household earnings here sit well above the national picture. The median household income of $157,192 places 02129 in the upper reaches of American postal codes, ahead of 97% of them. The US median for comparison is $70,109. Bear in mind that median income describes the midpoint household, not the average — it is not pulled upward by a handful of very high earners the way a mean would be.

Housing in 02129 costs far above the national median. A typical home is valued at $926,000 against a US median of $207,500, and median gross rent runs $2,258 a month. The split between owning and renting is fairly even at 49.6% owner-occupied, which tends to indicate a mix of housing types rather than one dominant form.

The building stock is dominated by small multi-family buildings of two to four units, which account for 33.2% of housing units here. The median construction year is 1938, making the housing here largely pre-war.

The population skews broadly in line with the national age profile, with a median age of 36 against 42 nationally. The average household holds 2.13 people, and 50.0% are family households.

Getting to work takes 32.6 minutes on average one way. The dominant mode is drove alone at 29.3% of workers, while 18.5% take public transit, 13.6% walk, 24.1% work from home. Commute patterns are one of the better proxies for how a place actually functions day to day.

Beyond addressing mail, 02129 does a lot of quiet administrative work. Retailers use it to calculate shipping and sales tax at checkout. Insurers use it to set premiums, since risk profiles vary geographically. Employers and marketers use it to define service areas. Government agencies use it to route benefits and organise reporting. If you have ever been asked for a postal code by a form that clearly does not intend to send you anything, this is why.

For anyone weighing a move, 02129 offers a compact profile of Charlestown: 19,994 residents, a median household income of $157,192, 71.4% of adults holding a bachelor's degree or higher, and an unemployment rate of 2.5%. A handful of figures like these answer more relocation questions than most neighbourhood guides do.

One caution worth repeating: a postal code is not a neighbourhood. 02129 may cover parts of several distinct areas, and a single neighbourhood in Charlestown may be split across more than one code. Boundaries also shift as USPS adjusts delivery routes. Treat the figures here as describing a delivery area, which is what they actually measure.