Nelligan led the Terps to their fourth consecutive NCAA Regional appearance in Fayetteville in 2012 after placing third at the EAGL Championships for the second consecutive season.
Under Nelligan's tutelage, the Terps scored their top-two all-time scores on vault last season. At Penn State on March 17, Maryland scored a 49.200 and followed up with its all-time best score of 49.225 at the EAGL Championships. Nelligan helped Katy Dodds and Ally Krikorian earned event championships and along with Karen Tang achieve First Team All-EAGL honors.
In 2011, Nelligan guided the Terps gymnastics squad to an undefeated record within the EAGL conference and the team's third consecutive NCAA Regional appearance. Prior to competing in the NCAA, Nelligan and Maryland placed third at the EAGL Championships, with senior Abbey Adams earning top All-Around honors.
Nelligan helped lead the 2010 Terrapin team to an NCAA Regional appearance, as well as a top-four finish in the East Atlantic Gymnastics League. In the 2010 season, Maryland earned a regular season record of 17-9 and finished in the top 30 in all five events.
A member of the coaching staff since July 2003, Nelligan is credited with securing several of the Terps' most talented recruiting classes ever. Nelligan's recruiting success helped him earn the title of recruiting coordinator in May 2006. His father, former head coach Bob Nelligan, believes what makes Brett a good recruiter is his believability, "He is selling something that he believes in, his father and the Maryland gymnastics system. He also goes out recruiting with a plan to bring in the highest ranked athletes."
A 2003 graduate of the University of Massachusetts with a degree in sport management, Nelligan competed three years of gymnastics for the Minutemen, serving as co-captain one year. An accomplished gymnast himself, Brett regularly made lineup on vault, floor exercise, high bar and pommel horse. On vault, he placed in the top 10 at the NCAA Championships and third at the ECAC Championships. He was also an Academic All-American and aided his team in winning two ECAC Championships. A versatile athlete, Brett turned to diving after the UMass gymnastics program was cancelled, and witnessed the team achieve its third straight Atlantic-10 title.
In recent years, Nelligan has spent his summers coaching at several gymnastics camps, including the University of Georgia, University of New Hampshire, University of Arizona, University of Rhode Island, University of Maryland Gymkana Gymnastics Camp, Woodward Gymnastics Camp, and at the U.S. Gymnastics Training Center in Holyoke, Mass.