McKernan was born in York, Pennsylvania. He is an army brat and has lived all over the country. His mother, Vicky, is a Lieutenant Colonel in the US Army Reserve. His father, Timothy A. McKernan Sr., is a Colonel in the U.S. Army and was deployed to Afghanistan at the time of the 2007 U.S. Championships and to Iraq at the time of the 2008 U.S. Figure Skating Championships.