One of the advantages for employees in a group health plan is the contribution most employers make toward the cost of the health coverage premium â in many cases, employers pay one-half or more of the monthly premium for an employee.
The basic format consists of five decimal numerical digits. An extended ZIP+4 code, introduced in 1983, includes the five digits of the ZIP code, a hyphen, and four additional digits that determine a more specific location within a given ZIP code. The USPS provides a free online lookup tool for ZIP codes.
Zip Codes Plus: The ZIP + 4 Code. In 1983, the United States Postal Service expanded the ZIP Code system to include four more digits. This is called the ZIP + 4 Code. The additional digits identify even more precisely the mailâs destination.