Donald Trump's long-time doctor, Harold N. Bornstein, has been calling himself a Fellow of the American College of Gastroenterology, but a new report late Thursday indicates Trump's physician has not been a member of that group for more than 20 years yet still uses the title.

MSNBC host Rachel Maddow stated the network received a tip from a viewer Wednesday that Bornstein's December letter regarding Trump's health had a flaw in it.

"The letters after the Trump doctor's name — there's his name. It says, M.D. for medical doctor and then it says, FACG, which stands for fellow of the American College of Gastroenterology," Maddow said.

"So we called them, and they said, 'yeah, that's right.' They said, quote, 'Dr. Bornstein joined the ACG in 1981. He was a fellow. When his membership lapsed in 1995.' He hasn't been affiliated with the ACG since that year. Given that, we asked if that means he should stop identifying himself the way he does, putting FACG after his name. They told us this: 'People who are no longer members of the organization would be expected to stop using FACG or any other reference to membership in the organization as they are no longer members.'"

Maddow reported MSNBC then reached out to Bornstein, who works at New York City's Lenox Hill Hospital, for comment.

"He told us, quote, 'FACG is a title they sell for a fee. In reality, it has no value,'" Maddow said. "In response to the inevitable follow-up question, Donald Trump's doctor told us that he will keep using this valueless title because it's part of his resume. And then he sent us a copy of this has framed certificate from back in the day a couple of decades ago when he was still paying his dues."

Trump's medical records and overall health have only come back into focus after his attacks on Democratic nominee Hillary Clinton's lack of stamina and poor health.

The Trump campaign has not issued a statement in response to Maddow's report.