Middletown covers 42 square miles and is divided into 12 different zip codes by the United States Postal Service. The location Middletown, NJ has 1 differents ZIP Codes. Middletown Zip Code - Get the zipcode for Middletown in Monmouth, (NJ) New Jersey - zip-codez.com Middletown, NJ ZIP Code - United States. Check the map below to check your ZIP Code. Stats and Demographics for the 07748 ZIP Code. Explore Middletown, New Jersey zip code map, area code information, demographic, social and economic profile. City Est. It also has a slightly higher than average population density. ZIP Code » United States » New Jersey » Middletown, NJ. ZIP Code New Jersey. Check the list of New Jersey ZIP Code. Detailed information on every zip code in Middletown ZIP code 07748 is located in eastern New Jersey and covers a slightly less than average land area compared to other ZIP codes in the United States. Zip Code 07748 - Middletown NJ New Jersey, USA - Monmouth County poblation Type ZIP Code; Middletown, NJ: 25.426: STANDARD: 07748 : Location of Middletown, NJ - USA. New Jersey ZIP code map and New Jersey ZIP code list. View all zip codes in NJ or use the free zip code lookup. Find your zip code by visiting the U.S. Postal Service Look Up page.The following zip codes make up the Middletown area: City of Middletown, NJ - MONMOUTH County New Jersey ZIP Codes. The people living in ZIP code 07748 are primarily white. load map.