A new area code was announced for the state of Kentucky in December 2012. The new 364 NPA will be introduced on March 3, 2014 and will overlay area code 270 covering KY cities such as Bowling Green, Elizabethtown, Owensboro, Paducah. 10 digit dialing will be mandatory starting February 1, 2014 for calls within the newly created overlay area 270/364. A permissive 10 digit dialing period is scheduled to begin on August 3, 2013. During the permissive dialing period local calls within area code 270 may be dialed using both 7 and 10 digit dialing.
See official NANPA announcement (PDF document)