Several technology start-ups, RoundTrip, Circulation Inc. and Kaizen Health have set up shop over the past two years to address this need. Each created an online portal that complies with federal regulations under the Health Insurance Portability and Accountability Act (HIPAA) and makes it easy to find, book and track customized rides for patients. Each company partners with health care facilities and transportation companies, which matches skilled drivers with patients’ needs. It even handles the insurance end.

Mark Switaj, who founded RoundTrip in early 2017, saw the transport care problem firsthand while working as an emergency medical technician and at other health care-related jobs in the mid-Atlantic region for 15 years. He saw what he called a clunky, layered system that was inefficient and unreliable for doctors and patients.

“I saw patients giving up — simply not going to their doctor anymore because they felt the ride was really a burden to them,” he said.

So, Mr. Switaj used his health care experience and business skills learned from Boston College and Georgetown University to create RoundTrip, which is based in Philadelphia. Now, a patient or social worker can log onto the RoundTrip portal and book a ride. The patient receives phone calls or texts, with real-time updates on the status of the ride, which can cost up to 40 percent less than a taxi voucher, be booked in about a minute and be tracked from start to finish, said Mr. Switaj. He said the no-show rate for medical facilities using his portal was less than 4 percent.

RoundTrip has 15 health care partners, many of which operate in dozens of locations, and 200 transportation organizations in its network in more than 23 states.

Circulation, based in Boston, has grown rapidly since it started in 2016. It partners with 95 health care providers (many of which have dozens of locations) in 45 states, up from three facilities in three states in 2016. John Brownstein, a professor at Harvard Medical School and chief innovation officer at Boston Children’s Hospital, came up with the idea for Circulation after the success of Uber Health, another program he created in 2014.