Nancy Lay-McCormick served as an International (FIFA) referee in 1999 and 2000, representing the highest tier of global officiating standards. At the professional level in the United States, she officiated in Major League Soccer from 1998–2000, making history in August 1998 as the first woman to referee a professional men’s match in MLS (NY/NJ MetroStars vs. Dallas Burn).

She later continued her professional career in the women’s game with the Women’s United Soccer Association from 2001–2002, contributing during the early development of top-level women’s professional soccer in the United States.

Nancy was a long-standing official within the United States Soccer Federation, serving as a National Referee from 1997–2002 and a US Soccer Referee from 1985–2006. She also officiated the 1998 National Cup Finals, a key national competition assignment recognizing top referees in the country.

In addition to field officiating, she contributed extensively to referee development and evaluation, serving as a National Assessor for US Soccer from 2002–2009. She was also active in collegiate officiating through the National Intercollegiate Soccer Officials Association from 1988–2002, including designation as a National Referee from 1990–2002, and worked as a high school referee from 1985–2006.

Her leadership extended into referee education and program development. In 2005, she developed the Florida State Referee Training Academy, and from 2005–2009 she created and directed the Women’s Referee Academy for US Soccer, designed to advance opportunities for women officials to referee men’s matches, including assignments at the National Veterans’ Cup.

Overall, Nancy Lay-McCormick’s career reflects both elite-level officiating achievement and sustained impact on referee development pathways, particularly for women entering professional and international soccer officiating.