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.
How Zip + 4 Works The extra 4-digit added on to the regular ZIP Code identifies a geographic segment within the 5-digit delivery area, such as a city block, office building, or individual high-volume receiver of mail (e.g., the phone company bill center, the White House), or any other delivery location that would aid efficient mail sorting and delivery.