One in three of America’s doctors are on Doximity, and that reach is only getting bigger.

Doximity, commonly referred to as a “Facebook for doctors,” has released an API and announced that more than 50 developer partners are building applications on it.

Medical application and software developers are using Doximity’s API to set up easy authentication systems — like Facebook Connect for doctors. Doctors won’t have to use multiple log-ins for the increasing number of health sites and services out there, and developers don’t have to build credentialing systems from scratch. All the information from a doctor’s Doximity profile gets integrated into the app’s system.

“Our goal is to make medical communication effortless, as easy as it is for the rest of us to shoot an email or text to a friend,” Doximity cofounder and CEO Jeff Tangney said. “We’ve done a great job of digitizing health information, but not of making it easy to access. We can take the technology the teenagers have in the waiting room and give it to the physicians and specialists seeing them in the exam room.”

Communication between doctors about patients and their health is extremely sensitive and highly-regulated. Doctors can’t just shoot a colleague a Facebook message to ask a question, however medicine is a profession that requires collaboration and dialogue.

Doximity bills itself as the largest HIPAA-secure medical network on the Internet. The network now has 220,000 members who use it to communicate with their colleagues, discuss medical cases and share research and files, and coordinate patient care.

Healthcare is an industry begging for improvement, and activity in the space is exploding as a result. National policies like mandatory electronic health records (EHR), the FDA’s newly relaxed guidelines on “mobile medical” apps, and the impending implementation of Obamacare have created a fertile environment for startups to build everything from insurance comparison apps to mobile otoscopes.

Anything that makes it easier to build a medical application, and makes it easier for doctors to sign up, has the potential for a big impact. A new physician joins Doximity’s network every 5 minutes, and as the developer network grows through the API, so will the number of doctors.

Current partners include US News & World Report, four of the top five medical schools, and startups like DICOM Grid, DocSpot, Figure1, Image32, itMD, MedConcert, Nephosity, and SmartSignOut.

Doximity launched in 2011 and has consistently released new products to digitize doctors’ work. Doximity CEO Tangney announced at HealthBeat 2013 that the company was putting “continuing medical education” online so doctors could get accredited without taking time away from their practice and could keep track of their credits. Last month, Doximity came out with a digital fax line for physicians.

The company has raised $28 million in venture funding from Emergence Capital Partners, InterWest Partners, and Morgenthaler Ventures. It is based in Silicon Valley.

VentureBeat's mission is to be a digital town square for technical decision-makers to gain knowledge about transformative enterprise technology and transact. Discover our Briefings.