Below is a list of Middlesex County MA zip codes. For your research we have also included Middlesex County Area Code, Time Zone, UTC and the local County FIPS Code. Each Middlesex County Massachusetts zip code has a center Longitude / Latitude point (the Middlesex County center is -71.290496826172 / 42.453998565674). For your convenience we have also indicated if that zip code in Middlesex County observes Daylight Savings time.