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 in the United States are 5-digit postal codes, with up to  6 additional digits to specify an exact delivery address. For  example, 12345-6789 is a ZIP+4 code, anâ¦d the delivery point  (usually the last two digits of the street number) are encoded in  the barcode for the full 11-digit code. 2 people found this useful.