Area Code +1-301-(2128000...2128999) located in Rockville, Maryland (MD), more detail is as below. Place International Dialing Code : 1 International Prefix : 011 National Prefix : 1 National Destination Code : 301 Subscriber Number From : 2128000 Subscriber Number To : 2128999 National Destination Code Length : 3 Uses National Destination Code : Yes National Significant Number Length : 10 Number Type : G (Geographic Land Line, Fixed Line) Carrier Name : VERIZON MARYLAND INC Click here to buy United States Area Code Database Other Information Language Code : en (English) Country Number : 840 (United States) Country Code : US (United States) Region Code : MD Region Name : Maryland City : Rockville Timezone : America/New_York Coordinated Universal Time : -05:00 Daylight Saving Time : Yes National Significant Number Minimum Length : 10 Latitude : 39.0900 Longitude : -77.1600 ‹ previous : +1-301-(2127000...2127999) next › : +1-301-(2129000...2129999) Dialling Instructions For trunk calls: 0 301 2128000 (Trunk Code + National Destination Code + Subscriber Number) For international calls: 011 1 301 2128000 (International Prefix + International Dailing Code +National Destination Code + Subscriber Number) Telephone Number List 2128000 ~ 2128999 (Count: 1,000) Example: +1-301-2128000 / 0111-301-2128000 (1301-2128000 / 1-301-2128000) +1-301-2128001 / 0111-301-2128001 (1301-2128001 / 1-301-2128001) +1-301-2128002 / 0111-301-2128002 (1301-2128002 / 1-301-2128002) +1-301-2128003 / 0111-301-2128003 (1301-2128003 / 1-301-2128003) +1-301-2128004 / 0111-301-2128004 (1301-2128004 / 1-301-2128004) ...+1-301-xxxxxxx / 0111-301-xxxxxxx (1301-xxxxxxx / 1-301-xxxxxxx) ...+1-301-2128995 / 0111-301-2128995 (1301-2128995 / 1-301-2128995) +1-301-2128996 / 0111-301-2128996 (1301-2128996 / 1-301-2128996) +1-301-2128997 / 0111-301-2128997 (1301-2128997 / 1-301-2128997) +1-301-2128998 / 0111-301-2128998 (1301-2128998 / 1-301-2128998) +1-301-2128999 / 0111-301-2128999 (1301-2128999 / 1-301-2128999)