USA Swimming, the national governing body for the sport, announced a revised eligibility policy for transgender athletes Tuesday. They are the first U.S. governing body to announce changes since the International Olympic Committee put forth new guidelines on the issues to go into effect in March.

Under the new, more restrictive policy, the collegiate career of Penn’s Lia Thomas could be over prior to the NCAA championships in March.

Much like USA Swimming’s previous policy, eligibility will be decided by an “Elite Athlete/Event Fairness Panel.”

The panel will review data submitted by the athlete in line with major policy revisions designed to, according to the policy, “ensure that athletes competing in the Female competition category who have transitioned from a Male biological gender assignment at birth, do not have an unfair advantage over their cisgender Female competitors in Elite Events.”

The panel decision weighs on two critical guidelines. The first involves a testosterone limit. Whereas previous policy of the International Olympic Committee set a standard of 10 nanomoles per liter of serum testosterone for at least 12 months consecutively prior to competition, the new USA Swimming standard is decidedly more stringent and will be applied before the athlete is allowed to apply as an “Elite” athlete, which would make them eligible to represent Team USA for any Olympic or FINA-sanctioned competition.

It shall be presumed that the athlete is not eligible unless the athlete demonstrates that the concentration of testosterone in the athlete’s serum has been less than 5 nmol/L (as measured by liquid chromatography coupled with mass spectrometry) continuously for a period of at least thirty-six (36) months before the date of Application.

In a release, USA Swimming explained the methodology behind this policy change. Much of it was based on a sample of competitive swim times across events among all USA Swimming member athletes at the Elite level:

The development of the elite policy therefore acknowledges a competitive difference in the male and female categories and the disadvantages this presents in elite head-to-head competition. This is supported by statistical data that shows that the top-ranked female in 2021, on average, would be ranked 536th across all short course yards (25 yards) male events in the country and 326th across all long course meters (50 meters) male events in the country, among USA Swimming members.

The policy change takes on added importance because of the effect it could have on the current NCAA season. According to the NCAA policy changes announced January 19, the USA Swimming policy may be the arbiter.

Such a possibility collides with the hopes of Thomas, a transgender woman student-athlete who currently holds two automatic qualifying spots in March’s Division I national championship.

USA Swimming states their elite policy applies to members of USA Swimming and specific contests that are considered “elite” events. Currently, Thomas is not a member of USA Swimming and collegiate conference or national championships are not listed as “elite” events by USA Swimming.