The leading players on the FIFA World Cup-winning USWNT filed a wage discrimination federal complaint against the United States Soccer Federation (USSF).
Carli Lloyd, who scored a hat-trick against Japan in last July's FIFA World Cup final, is among the complainants, joined by fellow co-captain Becky Sauerbrunn, goalkeeper Hope Solo, midfielder Megan Rapinoe and the highest-paid player in the team, striker Alex Morgan.
Morgan has been reported to collect a seven-figure income, however much of her pay comes from endorsements, and the USA women's team claim their basic earnings and bonuses from US Soccer should not be significantly short of what the men's team receive as is presently the case.
The five players say they represent the entire women's team, and claim their triumph in Canada last July transformed the finances of the USSF but has been inadequately rewarded.
The complaint has been directed to the US Equal Employment Opportunity Commission, and documents have been seen by Press Association Sport.
The complaint states: "Our team won its third World Cup title on July 5, 2015. The game captured the hearts of approximately 23 million viewers, making it the most watched soccer game in American TV history. We embarked on a post-Cup Victory Tour, which drew tens of thousands of fans to soccer stadiums across the United States and tens of millions of dollars into the Federation's coffers.
"In fact, according to the Federation's most recent annual report, it initially projected a combined net loss for the national teams of 429,929 US dollars for FY (financial year) 2016 (April 1, 2015 - March 31, 2016). But thanks almost exclusively to the success of the WNT, the Federation now projects a 17.7million US dollar profit in connection with these teams. And for FY 2017, the Federation projects a net profit from the WNT of approximately 5,000,000 US dollars, while projecting a net loss of nearly 1,000,000 US dollars for the MNT.
"Unfortunately the WNT's on-field accomplishments and revenue generation have not resulted in us or our fellow players earning equal or better pay than MNT players. In fact, our compensation pales in comparison to that of the MNT players.
"This despite the fact that, as our employer, the Federation is bound by federal law to compensate us at least equally to the rate at which it compensates MNT players given that the women and men perform the same job duties; have jobs that require equal skill, effort and responsibilities; and perform our jobs under similar working conditions."
Jurgen Klinsmann's men's team collected $US9 million for reaching the World Cup last 16, the complaint claimed, compared to the $US2 million shared between the women's side that coach Jill Ellis led to glory at Canada 2015.
It also compares match fees for friendlies, stating the available pay is almost three times higher for men than for women.
Lawyer Jeffrey Kessler is representing the group of players, and he told the New York Times: "This is the strongest case of discrimination against women athletes in violation of law that I have ever seen."
The USA women's side are also the reigning Olympic champions, while their men's counterparts have never gone beyond the FIFA World Cup quarter-finals or won an Olympic medal.
Formed only in 1985, the USA women's team have won the Olympics four times and the FIFA World Cup three times in their short existence.
Lloyd told ABC's Today programme: "I think the timing is right. I think that we've proven our worth over the years. Just coming off of a World Cup win, the pay disparity between the men and women is just too large. And we want to continue to fight."
Solo said in a statement: "The numbers speak for themselves. We are the best in the world, have three World Cup championships, four Olympic championships, and the USMNT get paid more to just show up than we get paid to win major championships."
Kessler, from the Winston & Strawn law firm, has previously represented athletes including NFL star Tom Brady and Paralympic sprinter Oscar Pistorius, winning the latter the right to race against able-bodied athletes which led to him running in the London 2012 Olympics.
US Soccer said in a response on Thursday: "While we have not seen this complaint and can't comment on the specifics of it, we are disappointed about this action. We have been a world leader in women's soccer and are proud of the commitment we have made to building the women's game in the United States over the past 30 years."