what is the area code for sterling mass.?
978 and 351. Sterling, MA is currently using an area code overlay in which area codes 351 and 978 serve the same geographic area. Ten digit dialing (area code + seven digit number) is necessary. In addition to Sterling, MA area code information read more about area codes 351 and 978 details and Massachusetts area codes. Sterling, MA is located in Worcester County and observes the Eastern Time Zone. View our Times by Area Code tool.