WASHINGTON — When Senator John Barrasso, Republican of Wyoming, sought guidance on how to protect his family, including his 94-year-old father-in-law, when he returned home from the nation’s capital amid the coronavirus pandemic, a doctor offered him some blunt advice.
Don’t go home just yet, Dr. Brian P. Monahan, the attending physician of Congress, told Mr. Barrasso, directing him to quarantine for 14 days before rejoining his family. “You’re a visitor,” Dr. Monahan said.
But when House Democratic leaders wanted counsel on whether they could safely reconvene in the Capitol with Covid-19 still spreading — a debate with political dimensions as a partisan divide was emerging across the country over how quickly to reopen — Dr. Monahan was less absolute. Returning to Washington carried health risks he would not recommend taking, he told Speaker Nancy Pelosi of California and Representative Steny H. Hoyer of Maryland, the majority leader. But it was up to them to decide what to do.
It was typical of Dr. Monahan, the 59-year-old Navy rear admiral who is known in the halls of the Capitol as much for his meticulous attention to medical detail as he is for his efforts to stay completely out of politics.
“He is both an executive with lots of health care responsibilities — particularly now — and also has the unique relationship with members that a small-town doctor would have with the patients he knows and sees,” said Senator Roy Blunt, Republican of Missouri and chairman of the Senate Rules Committee. “He’s in a unique role at a unique time”
As government doctors have emerged as trusted public voices and political figures in the face of a fearsome pandemic — appearing in White House news conferences and as witnesses at marquee hearings — Dr. Monahan has maintained an uncommonly low profile.
He never issued a public statement offering his opinion on whether Congress should reconvene, although he shared his warnings with House leaders and privately told senior Republican officials that his office did not have the capacity to screen all 100 senators for the coronavirus when they returned to work. When Alex M. Azar II, the health secretary, said he would send 1,000 tests to Capitol Hill to accommodate them, Ms. Pelosi and Senator Mitch McConnell, Republican of Kentucky and the majority leader, turned down the offer, wary of the optics of receiving special treatment at a time when testing was scarce — and prompting President Trump to suggest on Twitter that, “maybe you need a new Doctor over there.”
Dr. Monahan, who declined to be interviewed, has been a calm and professional voice of reason during the pandemic, according to interviews with more than two dozen lawmakers, Capitol officials and medical professionals who know him. They say he has taken a personal interest in his influential clientele, which also includes the nine Supreme Court justices, even as he fields politically charged questions about reopening, testing and precautionary measures.
Operating out of a nondescript clinic tucked away in the heart of the Capitol, Dr. Monahan and a small staff have been exceedingly busy since the pandemic took hold, consulting with lawmakers who have contracted Covid-19 or exposed to someone infected with it, doling out health recommendations in detailed memos ahead of votes, and producing a series of videos released on an internal website to educate lawmakers and their staff on how to protect themselves.
Dr. Monahan has filmed and produced the videos by himself in his office, often seated next to an elaborate bouquet of white flowers and a tiny plastic model of a pangolin, the scaly mammal that may have been an intermediary carrier of the virus.
In the videos, he typically walks through the most recent recommendations offered by the Centers for Disease Control and Prevention and demonstrates medical equipment, such as a thermometer and a variety of masks (including one made by his wife, using a black shopping bag and a sewing machine.)
“He has a big job — two houses of Congress, two parties to deal with — but he’s not political in any way,” Ms. Pelosi said. “He treats us all with respect, and we respect his judgment in return.”
Dr. Monahan in 2009 became the seventh man to serve as attending physician, taking up a position that has always been held by a Navy doctor. The House first approved a Navy officer to work out of the Democratic cloakroom in 1928 after one lawmaker died and two collapsed, with several hours passing before a doctor could arrive in each case. Two years later, the Senate extended that doctor’s jurisdiction to include its own members, leading to the establishment of the Office of the Attending Physician.
The office provides care to lawmakers for a fee, as well as offering some services and emergency care to staff and tourists. The first physician, Dr. George W. Calver, who began his work just before the start of the Great Depression, displayed placards in cloakrooms and elevators across the Capitol with his nine “Commandments of Health,” including, “Accept Inevitables (don’t worry)” and “Relax Completely.”
Dr. Monahan was born in Connecticut, the son of Irish immigrants who came to the United States in the 1950s. His mother grew up in Kilkee, while his father grew up in a house with a thatched roof without running water or electricity in Lissycasey. The first in his family to attend college, he worked full-time at a supermarket while commuting in a yellow Volkswagen Beetle to Fairfield University, a Jesuit college — an education, he would tell graduates in 2011, that meant, “you are called to be ‘men and women for others.’”
He studied biology and chemistry, and after graduating, joined the Navy through its Health Professions Scholarship Program, enticed in part by the offer of free tuition and a living allowance in exchange for a commitment to three years of service.
“Brian was always the smartest kid in the class,” said Dr. William Dahut, a medical oncologist who spent time with him in both medical school and the Navy. “If there was a publication or data, Brian knew that data and knew that well.”
In 1989, as a resident in the cardiology ward in what was then the National Naval Medical Center in Bethesda, Md., he treated a 39-year-old woman for potentially fatal cardiac arrhythmias. The patient had taken the popular antihistamine Seldane, and his contribution to research on that medicine — and its connection to the arrhythmias — later helped lead to its removal from the market.
Dr. Monahan rose through the ranks of the Navy, becoming a professor of medicine and pathology at the Uniformed Services University of the Health Sciences in Maryland, as well as participating in a number of national organizations related to cancer, oncology and hematology.
While serving as the Chairman of the Department of Medicine at the university, he received a call for a meeting in which officials with congressional leadership asked him to become the attending physician on Capitol Hill when his predecessor retired.
“He was the one who advised me to go to the hospital,” said Representative Ben McAdams, Democrat of Utah and one of the first lawmakers to contract the virus, said of Dr. Monahan. “He was clear: ‘I strongly recommend you go to the hospital — this is serious.’”
The congressman has spoken with the doctor at least a dozen times since, he said in an interview on Thursday — but had yet to meet Dr. Monahan in person.
An avid photographer, Dr. Monahan’s photos are present in offices around the Capitol — and he has been known to offer advice on how to best capture a scenic landmark or vista on trips overseas.
He checks in with his powerful patients frequently, including long after they have recovered.
“I’ve been around for a long period of time, and he just takes more of a personal interest than anyone else I’ve ever known in that position,” said Senator James M. Inhofe, Republican of Oklahoma and chairman of the Senate Armed Services Committee, who has been on Capitol Hill for more than three decades. “He just seems to be genuinely interested in me — and he’s that way with everybody.”
Nicholas Fandos and Eric Schmitt contributed reporting. Kitty Bennett contributed research.