Approximate service area of Area Code 606 is in red. Area code 606 is a telephone area code serving the easternmost part of the state of Kentucky. Cities and towns in the area code include Ashland, Morehead, Hazard, Middlesboro, Somerset, London, Corbin, Paintsville, Pikeville and Maysville.Most of its service area lies within the Kentucky region known as the Eastern Kentucky Coalfield.otably, it was one of the first three area codes with 0 as the middle digit that wasn't assigned to an entire state; the others were area code 507 in Minnesota and area code 607 in New York.