The telemedicine service Doctor on Demand is doubling down on its enterprise partnership business, and is taking a new $50 million injection of venture capital funding to do it.

The company is getting some traction with self-insured enterprises, who are offering the Doctor on Demand service to their employees as an add-on to their health insurance benefits.

Doctor on Demand will use the new investment money to market the existing service and to “build onto the enterprise sales team,” said cofounder and CEO Adam Jackson. “It’s a ‘just add water’ growth round,” he said.

The names of the investors were not disclosed.

The San Francisco-based company’s last raise came last August with a $21 million round led by Venrock. Shasta Ventures and celebrity investor Richard Branson also participated.

The company raised a $3 million seed round in late 2013 from Venrock, Andreessen Horowitz, Google Ventures, Lerer Ventures, Shasta Ventures, and Athenahealth chief executive Jonathan Bush.

Doctor on Demand has now taken a total of $74 million in venture funding.

The new funding comes as the field of telemedicine apps continues to grow, but the number of people using video doctor visits continues to grow, too. Research firm IHS Health projects that the telemedicine industry will grow to $4.5 billion by 2018.

“I think telemedicine has turned a corner,” Jackson told VentureBeat. “I think it’s been accepted by the enterprise as a cost saver.” Indeed, offering telemedicine for simple medical problems can save employers money by helping keep employees out of the doctor’s office and on the job.

Since announcing Comcast as its first Fortune 100 customer, Doctor On Demand has aggressively grown its employer base. More than 200 employer customers now offer physician and psychologist video visits via Doctor on Demand through employee health and wellness programs.

Doctor on Demand said that through its enterprise partnerships and its partnerships with national health plans such as UnitedHealthcare and Blue Cross Blue Shield Association, more than 25 million Americans now have in-network or subsidized access to its telemedicine service.

Jackson pointed out that Doctor on Demand works with employers in a different way than other telemedicine providers. Other telemedicine providers, he said, work on a subscription basis, charging employers a per-employee, per-month fee, plus a consultation fee for every virtual visit. Doctor on Demand, on the other hand, gets paid only when an employee does a video visit with a doctor. “We take all the risk,” Jackson said.

Doctor on Demand now has roughly 85 full-time employees, plus 30 on-staff physicians.