Area code 620 covers telephone exchanges in most of southern Kansas. It was created as the result of a split from 316 on February 3, 2001. The area code stretches across the southern half of the state, from the Colorado border in the west to the Missouri border in the east. It completely surrounds 316, which now only serves Wichita and its inner suburbs, making it one of the six pairs of "doughnut area codes" in the numbering plan. Permissive dialing of 316 across southern Kansas continued until November 3, 2001.
The most populous cities covered by the area code are Dodge City, Garden City, Hutchinson and Pittsburg.
620 was created due to the growing proliferation of cell phones in the Wichita area. With the great majority of the old 316's landlines and cell phones located in the Wichita area, 620 is one of the most thinly populated area codes in the nation. Based on projections in 2023, southern Kansas will not need another area code until about 2027.[1]
Prior to October 2021, area code 620 had telephone numbers assigned for the central office code 988. In 2020, 988 was designated nationwide as a dialing code for the National Suicide Prevention Lifeline, which created a conflict for exchanges that permit seven-digit dialing. This area code was therefore scheduled to transition to ten-digit dialing by October 24, 2021.[2]