The suit alleges Maroney was sexually abused by Nassar from about 2009 to 2013 while she was a teenager. It seeks to invalidate the non-disclosure agreement and seeks unspecified damages.
USAG responded in a statement emailed to Reuters that the "concept of confidentiality was initiated by McKayla’s attorney, not USA Gymnastics."
Maroney's court filing states she was forced into the confidentiality agreement "after suffering for years from psychological trauma of her sexual abuse at the hands of Nassar, and in need of funds to pay for psychological treatment..."
This month, Nassar was sentenced by a U.S. District Court judge in Michigan to 60 years in prison on federal child pornography charges that grew out of a sex abuse investigation.
Nassar was the team physician for the Michigan State University gymnastics and women’s crew teams. He served as the USA Gymnastics physician through four Olympic Games.
Just months after Maroney signed the confidentiality statement, the lawsuit says, USAG "publicly discussed the exact same subject matter it sought to conceal..."
The Wall Street Journal reported on Wednesday that USAG paid Maroney a $1.25 million settlement.
As well as USAG and Nassar, the lawsuit also names the U.S. Olympic Committee and Michigan State University.
A lawyer representing Nassar did not immediately respond to a request for comment.
USGA responded with a statement which says, in part: "In 2016, McKayla’s attorney at the time, Gloria Allred, approached USA Gymnastics, requesting that the organization participate in a confidential mediation process."
"USA Gymnastics cannot speak to the mediation process, which is confidential and privileged under California law. The process culminated in a settlement agreement that included a mutual non-disclosure clause and a mutual non-disparagement clause.
"The settlement in 2016 was in accordance with state law, despite what has been alleged. At all times, McKayla was represented by Allred, a California-based attorney, who actively negotiated and approved the settlement agreement signed by McKayla."
Allred said she had no comment on the statement by USAG.
The USOC said in a statement it had first learned of sexual abuse by gymnastics doctor in 2015, and that USAG had indicated it was in the process of contacting law enforcement about the matter.
(Reporting by Andrew Both in Cary, North Carolina; Editing by David Gregorio)
