It’s 6 p.m. on a Friday and you just smashed your finger in the car door. It hurts. And as it turns an alarming shade of purple, you ponder your options.

Head to the emergency room and face what may be a long wait and a big bill? Or tough it out until Monday when your primary-care physician might squeeze you in between appointments?

Increasingly, in such cases, the answer is “neither.” Instead, you’ll likely head to an urgent-care center, a health care option that bridges the gap between the doctor’s office and the emergency room, offering walk-in care for extended hours.

With on-site physicians, physician assistants, and nurse practitioners, plus the ability to take X-rays, do lab tests, and write prescriptions, urgent-care centers are popular both for their convenience and their comparatively low cost. So much so that there are now more than 2,700 such outposts in the United States, according to the Urgent Care Association of America.

In addition to treating the type of minor ailments that send people to the doctor’s office, an urgent-care center like Patient First, which has 58 centers in the Washington, D.C., area, Virginia, Maryland, Pennsylvania, and New Jersey, “can handle a large percentage of what is typically seen in an emergency room,” says Ian Slinkman, Patient First’s vice president of marketing and public relations. Most often, that means treating upper respiratory infections, fevers, sprains and strains, cuts, bruises, back pain, and routine illnesses, as well as such things as broken bones and stitches.

Urgent-care centers even provide ongoing primary care for some patients, but, for many, Patient First is “a complement to primary care,” says Slinkman, who notes patients can request their medical records be sent to their primary-care physician for continuity of care. “We very much work in a collaborative fashion.”

There are, of course, some challenges with care delivered outside a patient’s primary-care office.

Like urgent-care centers, Convenient Care Clinics (CCCs)——those mini-clinics that have popped up in pharmacies, grocery stores, and big-box stores—are proliferating. With close to 2,000 retail clinics nationwide, the industry is expected to grow up to 25 percent per year, according to the Convenient Care Association, which represents CCCs.

CCCs typically provide basic non-emergency health care services from a nurse practitioner or physician assistant, but don’t have on-site X-ray or lab capabilities. And they tend to be cheaper than other options: Most accept insurance co-pays, but, even without insurance, typical visits cost around $75, according to the Convenient Care Association.

“We are at a time when there has never been so much change,” says Mark Lamos, president and medical director of Greater Baltimore Medical Associates, who notes health care is now even being delivered via kiosk at supermarkets like Wegmans, which is offering virtual medicine through an app called Doctor On Demand.

There are, of course, some challenges with care delivered outside a patient’s primary-care office. The lack of integration between health care providers means urgent-care centers and CCCs sometimes don’t know your health history.

Physician groups like MedChi, the Maryland State Medical Society, though supportive of urgent-care centers, have taken a wary view of CCCs, in part because they’re not usually staffed by doctors. But the Convenient Care Association notes that nurse practitioners, who are board-certified and have master’s degrees in nursing, are qualified to deliver patient care, as are physician assistants. “There are limitations associated with nurse practitioners and physician assistants,” says Lamos, an M.D., “but I can tell you they provide excellent care. There’s a role for them for urgent care and chronic-disease management.”

One thing seems clear: Whoever is providing care——whether it’s doctors, nurse practitioners, or physician assistants—where they deliver it will be heavily influenced by consumers. “If anything tells us what’s going to happen,” says Lamos, “it’s whatever is easiest, least expensive, and most convenient.”