Zip Code 08619 is located in the state of New Jersey in the Philadelphia metro area. Zip code 08619 is primarily located in Mercer County. The official US Postal Service name for 08619 is TRENTON, New Jersey. Portions of zip code 08619 are contained within or border the city limits of Mercerville-Hamilton Square, NJ, Trenton, NJ, . The area code for zip code 08619 is 609.