Shattenkirk, entrenched in the US National Team Development Program, first represented the United States in the 2006 World U-17 Hockey Challenge, helping collect silver. The following year, as captain of the under-18 development program, Shattenkirk was selected to the 2007 IIHF World U18 Championships. He again contributed to the United States winning silver, gaining selection to the All-Star Team and named the Tournament's Best Defenseman.