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.
The first three digits of a ZIP code refer to a sectional center or a large city. The last two digits refer to a specific post office facility or delivery area. In ZIP+4 format, a hyphen is required to separate the first five and last four of a ZIP code. The first two of the +4 code refer to a sector or a few blocks. The last two of a +4 code refer to a specific segment or one side of a street.