| Start Date | 05/02/2001 |
| Current Time in Area Code 857 | 857> EDT |
| Timezone | Eastern Daylight Time |
| Regional Market Area | Metro Boston |
| Population (2020) | 797936 |
| Adjacent Area Codes | 339,617,781 |
| Overlay Area Codes | 617 |
| Suffolk County |
| Boston |
| Brookline |
| Cambridge |
| Chelsea |
| Everett |
| Newton |
| Quincy |
| Somerville |
| Watertown Town |