Area Code Atlas

NPA 859 split from 606

Area code 859 was created in 1999 from a split of area code 606, serving Lexington and central Kentucky. The split allowed the rural eastern region to retain 606, while the more populous central region adopted 859, including Northern Kentucky.

606 NPA Split, Creating 859 NPA - Kentucky

Permissive 10-digit dialing begins in 859

Permissive 10-digit dialing began in area code 859 on April 24, 2021, allowing both 7-digit and 10-digit dialing in preparation for the transition to mandatory 10-digit dialing due to the nationwide designation of 988 as the National Suicide Prevention Lifeline code.

Mandatory ten-digit dialing in area code 859 due to 988 conflict

On October 24, 2021, area code 859 transitioned to mandatory ten-digit dialing due to the nationwide designation of 988 as the National Suicide Prevention Lifeline code, which conflicted with existing seven-digit dialing in the area. This change was implemented alongside similar transitions in other area codes, including 513 in southwestern Ohio, to resolve conflicts with the 988 central office code.

Projected exhaust of NPA 859

Projections as of 2023 estimate that area code 859 will not exhaust its central office code supply until about 2047.