The numerical designator 606 serves as a geographic prefix assigned to telephone numbers within a specific region. As an area code, it is dialed before the seven-digit local number when placing a call to locations within its designated service area from outside that area. For example, a call to a number within the 606 area from another area code would be dialed as 1-606-XXX-XXXX.
This particular code is essential for telecommunications routing, enabling efficient connection of calls across the North American Numbering Plan (NANP). It provides a unique identifier for a large section of eastern Kentucky. Its implementation and subsequent use facilitated growth in communication infrastructure within that region, allowing for greater business connectivity and personal communication networks. The establishment of 606 assisted in organizing and managing the increasing demand for telephone services as the population and economy of eastern Kentucky developed.