Over 5 million Americans already use ZocDoc to find doctors and book medical appointments online. Now the service is getting an upgrade so that it’s more useful to businesses and their employees.

Workers who visit the site will see options tailored to their employer’s health insurance, doctors who accept those plans, and appointment times more likely to work with their schedules. When an investment banker signs on, for example, the service will show appointments in the early morning, early evening, or on the weekend–times outside of normal trading hours.

ZocDoc announced the new subscription service, ZocDoc for Business, on Wednesday. The goal is to help workers find the right doctor, but in a more personalized way based on where they work.

“Employers want to make sure employees are getting the right preventative care because they’re paying for it,” Cyrus Massoumi, ZocDoc’s CEO, tells Fortune.

Massoumi views ZocDoc for Business as a convenience for both employers and employees. Workers can get medical appointments much faster than the national average of 18.5 days, in theory. Meanwhile, employers can trim costs traditionally wasted on so-called out-of-network providers, doctors who don’t typically accept an employer’s insurance.

Massoumi also argues that companies that use his service will increase worker productivity. Fewer employees will have to take time off to visit their doctor after they see how easy it is to schedule an appointment outside their workday, he said.

For example, the New York region of KIPP Public Charter Schools, an early ZocDoc for Business client, saw teacher absenteeism fall 30% after it enrolled, Massoumi said. As a result, KIPP saved money because it didn’t have to hire as many substitute teachers to fill in while staff sat in their doctors’ offices. Other initial customers include IAC, NASDAQ OMX, Gilt Groupe, and Foursquare.

ZocDoc, based in New York, has around 550 employees and has raised nearly $95 million in total funding from Khosla Ventures, DST Global, Salesforce.com CRM  CEO Marc Benioff, Amazon  AMZN  CEO Jeff Bezos, and others. Getting even a small piece of the $600 billion employer benefits market would be a major coup. Although challengers like Patient Fusion remain in the consumer market, ZocDoc’s long-term growth lies in tackling the overall health care system. With its consumer business, there’s only so much potential growth. Eventually, keeping users returning to schedule appointments could become a real issue.

Indeed, for Massoumi, anywhere in the health care system where there’s an opportunity to innovate, he sees an opportunity for his startup. Says Massoumi: “We are in the business of solving patient problems.”