The township has two large divisions, Milton and Lake Hopatcong. Each half has its own first-aid squad, fire department substation and set of elementary schools. Addresses in the Milton section of the township are classified under the Oak Ridge mailing city, which is shared with a portion of West Milford Township, or in the Newfoundland mailing area, shared with a portion of West Milford and Rockaway Township. Addresses in Lake Hopatcong use either Lake Hopatcong (not to be confused with the Hopatcong mailing city used in the Borough of Hopatcong) or Wharton as their mailing city. In 2016, there was an effort to change the mailing address for the Lake Shawnee section of town from a Wharton, NJ 07885 ZIP code, to a Lake Hopatcong, NJ 07849 ZIP code. The effort was narrowly defeated. In 2026, a new effort will be made to change the mailing address ZIP code to Lake Hopatcong, NJ 07849. The Jefferson Township Municipal Building, Middle School, High School, Recycling Center and school bus depot are positioned at the boundary between the two halves of the township.