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.n 1999, most of the northwestern portion of the old 606 territory, including Lexington and Northern Kentucky, split off as area code 859.