Mr. Summersgill's practice focuses on intellectual property and commercial litigation. He represents clients—such as Intel, Ford Motor Company, Bank of America, Eastman Kodak Company, Vonage and Vanguard—in a variety of jurisdictions across the country. He has successfully tried multiple cases before the International Trade Commission (ITC) and in the federal district courts. He has also argued appeals to the Federal Circuit and the First and Ninth Circuit Courts of Appeals.

Mr. Summersgill served as an Assistant District Attorney for the Commonwealth of Massachusetts for six months in 2002. As an ADA, he tried 20 cases to verdict.

Mr. Summersgill is a member of WilmerHale's Management Committee.