McComas was born in Bethesda, Maryland; his family moved to Harrison, Arkansas when he was four years old. At age sixteen, he attended a Paul Overstreet concert; while at the concert, Overstreet gave McComas the address of his publishing company. McComas submitted a demo tape to the publishing company, who then encouraged him to continue working on his writing skills. McComas later attended college, but soon dropped out to move to Nashville, Tennessee.