On a recent morning at a free walk-up coronavirus testing site in the District of Columbia, blue-gowned workers wearing face shields and masks often stood by with nothing to do. They mostly outnumbered those seeking tests.

Between the District’s public lab and those associated with hospitals and other care providers, officials say there is capacity to test about 5,500 people a day. But the number of people asking for tests hasn’t reached anywhere near that figure.

On Wednesday, only 642 test results were reported. The next day, 817 test results came in, according to the city’s website.

While officials say those numbers may be tied to reduced testing during Memorial Day weekend, the District has averaged little more than 1,000 tests a day recently and has only broken 1,500 once, in mid-May. The city reported only 344 test results on Friday.

Demand for testing has been slow in the District and elsewhere, experts say, because of a lingering sense of test scarcity, confusion about who qualifies to get one, a lack of easy access in underserved communities and skepticism about testing operations.

Public health experts say the District should be testing much closer to its full capacity to contain outbreaks as the city begins to reopen. The Harvard Global Health Institute has estimated that, based on the District’s population, the city should be running 5,857 tests a day to detect those with the virus and get them to isolate before spreading it further.

While city health officials reject such per capita targets as arbitrary, they acknowledge a need to proactively seek more people to test.

“I want to emphasize that we have the ability to test anyone who needs a test,” Mayor Muriel E. Bowser (D) said at a news conference Wednesday. “So if you need a test because you are sick or because you have been exposed to covid-19, we’re asking you to call your doctor, or to call our citywide testing line to get a test. If you need a test, get a test.”

During the first few months of the U.S. outbreak, shortages of swabs and other supplies forced doctors and health officials to ration testing.

As those shortages eased in late April, the Centers for Disease Control and Prevention expanded guidelines for who should be tested to those without symptoms who were prioritized by health officials or clinicians for any reason.

Since then, most places have dramatically relaxed criteria for who should be tested, yet many states have struggled to fill newfound capacity with test seekers.

Despite its challenges, the District has done more testing per capita than most states, including Maryland and Virginia.

Though Virginia has also moved past statewide testing supply shortages and ramped up its testing, Loudoun County officials recently offered drive-up, no-appointment free testing at a park only to run out of testing supplies several hours before closing time, frustrating some residents.

Bowser said District-run sites now are instructed to test anyone who thinks they need it. Yet so far even priority groups such as health care and grocery store workers are not all being tested routinely.

A big part of the problem remains confusion about who qualifies. This week, a Q&A on the District’s website still said only those with symptoms could get tested.

“Resources for testing are limited” and “Testing must be prioritized,” the outdated site said, suggesting that even people with mild symptoms might forgo testing because “a positive test result would not change how they should handle their illness.”

“We’ll address that right away,” Bowser said Friday when a reporter brought the language to her attention, and within a few hours officials removed it.

D.C. officials are taking steps to expand testing to more people, especially as the city takes tentative steps toward ending a prolonged economic shutdown, such as allowing outdoor restaurant dining, appointment-only haircuts, and curbside pickup from stores deemed nonessential.

“As we go into Phase 1, we recognize that more people are going to be moving around and should get tested,” Bowser said.

On Friday, the CVS Pharmacy chain opened three drive-through testing sites in the District, at which people can swab themselves while in their cars.

Starting Monday, District officials will open a testing site on F Street in Northwest, where no appointment will be needed, and they are relocating a site on the United Medical Center campus to a more walkable and public transit-accessible location in Anacostia, an area hit hard by the virus.

A mobile testing site is making rounds at congregate settings such as nursing homes, which have suffered deadly outbreaks, and the District is targeting high-density and vulnerable neighborhoods for pop-up testing. Testing is free at District sites, and federal regulation requires health insurers to cover tests for patients at private hospitals and doctor’s offices with no out-of-pocket charges.

“We have to get the word out,” said Tamara Smith, chief executive of the D.C. Primary Care Association, a support organization for community health centers.

“D.C. Health is beginning to go out into communities where they know there’s higher density living situations, where people may not be able to quarantine as easily, and they’re just having open testing,” Smith said. “That is going to greatly expand the amount of testing.”

Doctors, too, have sometimes been slow to recognize expanded capacity for testing, experts say, and have ordered too few tests as a result.

Maria Hernandez sought out testing at a walk-up testing site at the University of the District of Columbia Community College’s Bertie Backus campus Thursday, after her roommate had shared a drink with someone who tested positive.

“I’m here because my roommate got exposed, and he doesn’t want to get tested,” she said.

Hernandez, a 30-year-old PhD student, said her roommate’s doctor told him there was no need for a test, so he decided against it.

Rather than argue with her roommate, Hernandez decided to get a test for herself.

“It wasn’t that bad at all,” she said of the nose swab.

Also seeking a test was a middle-aged woman who works as a nurse at Sibley Memorial Hospital in Northwest Washington. She had no symptoms but needed a test before seeing a surgeon about an elective procedure, said the nurse, who spoke on the condition of anonymity because she was not authorized by hospital officials to speak.

Though she has worked with coronavirus patients throughout the pandemic, the nurse said she hasn’t seen a need to be tested until now, given the use of personal protective equipment and other precautions at the hospital where she works.

“Today I could get tested, and tomorrow I could go to the grocery store and catch it,” she said. “So are you going to get tested every day?”

Edward Smith, director of the District of Columbia Nurses Association, a labor union, said all first responders and health care workers should be getting tested routinely.

“We know we can’t test them every day, but the more often, the better,” he said.

Universal testing for health care workers is critical given the large portion of coronavirus carriers who show no symptoms, Smith said.

“You’re looking at quite a big chunk of the population that’s walking around, not thinking they’ve got any problems, including nurses.”

While getting a test one day is no guarantee a health care worker won’t contract the virus the next, Smith said, “they’ll know, at least at that point in time, they’re not giving the virus to anyone, including their patients, including anybody that they see in the street, and certainly most importantly, their family.”