She was photographed for the February 2007 issue of Playboy, partially clothed and completely nude. According to the Lackland AFB spokesman, such actions do not meet the high standards expected of airmen nor the Air Force's core values. Manhart has stated that she dreamed of being on Playboy at age 12.
Reference to Manhart's case appears in an academic article authored by Major Kelly L. McGovern in the March 2008 issue of The Army Lawyer. To quote, "Former Air Force Training Instructor Sergeant Michelle Manhart posed in and out of uniform for the February 2007 edition of Playboy magazine. Photos included Manhart in uniform yelling and holding weapons under the headline, 'Tough Love'. On the subsequent pages, Manhart appeared 'partially clothed, wearing her dog tags while working out, as well as completely nude.' The pictures hit the stands in January 2007, and the Air Force immediately relieved her of her duties pending an investigation. The Air Force then took administrative action against Manhart. She received a letter of reprimand for violating the uniform regulation and discrediting the armed forces. The Air Force also administratively demoted Manhart from staff sergeant to senior airman. In February, she was voluntarily discharged from the Air Force citing reasons of personal convenience."
According to Playboy publicist Theresa Hennessey, two other active-duty servicewomen (both from the United States Navy) appeared in Playboy, Lieutenant Frederica Spilman in the June 1998 issue and IT2 Sherry Lynne White in the September 2000 issue. (White was discharged a few months prior to the end of her enlistment, Spilman was honorably discharged.) Seven women were featured in a "Women of the Armed Forces" pictorial in the April 1980 issue.
In April 2015, Manhart was detained by Valdosta State University police after stealing a flag from protesters who were stepping on it during a protest on university grounds. Manhart refused to return the flag to the protesters or give it to police, and was detained. Manhart claimed her actions were done to defend the flag from further desecration and was planning on disposing of it in the proper manner. The university police and protesters declined to press criminal charges against Manhart; however, she was given a criminal trespass warning which effectively bans her from all university activities, including graduation and football games.