When you dial a local phone number, you only need to input seven digits on your phone. However, if you want to call someone who lives far away, you must add a three-digit area code at the front of the number. Some states only have one or two area codes, but highly populated states have several. For instance, as of 2017, California had issued 26 area codes. Maryland had five and Massachusetts had nine. It doesn’t matter how big a state is geographically. What matters is the population density. Area codes are based on population.
Massachusetts’s first area codes, 413 and 617, were issued in 1947. These were the only area codes in the state for 41 years. In 1988, 508 was added because of the state’s population growth. Area codes 781 and 978 were added in 1997 and 339, 774, 351, and 857 were added in 2001. The last four are overlay codes. You can learn more about the history of area codes in Massachusetts, as well as fun facts in the following infographic.
People in Massachusetts were originally opposed to overlay area codes because it meant they would need to dial 10 digits instead of seven for seemingly local contacts. However, new area codes were necessary to accommodate a high population density. Code 413 is the largest area code, and it covers all of western Massachusetts. Code 617 covers east-central Massachusetts, 508 covers south-central Massachusetts, 781 covers the South Shore and most suburbs in Boston, and 978 covers north-central and northeastern Massachusetts.
Daryl Green 
Barbara Ratliff