If most American citizens are unaware that the Commissioned Corps of the U.S. Public Health Service is one of the nation s seven uniformed services, it wouldn t come as a surprise to many of its nurses, who make up the largest contingent of the corps. During the pandemic we ve been highly visible, but still, people didn t even know there were PHS officers on TV standing behind Dr. (Anthony) Fauci and the president, said PHS Lt. Cmdr. Staci McNair, a nurse and the medical director of the Addiction Services Element at Joint Base Andrews in Maryland. They might ve thought they were Coast Guard, she added, because the uniforms look similar.