Blue Cross Blue Shield of Massachusetts will pay nearly $20 million to turn the Boston area’s Hubway bike share system into Blue Bikes and expand the program with more than 1,000 new bikes and more than 100 new rental stations across the region.

“Blue Cross is committed to helping Massachusetts residents lead healthy lives, and this program is a way to bring that to life,” said Jeff Bellows, vice-president of corporate citizenship for BCBS. “Being a health-care company, it’s in line with what we want to do.”

BCBS will pay $18 million over six years to be the sole sponsor of the bike share system, which will be renamed Blue Bikes. The money will be used in part to fund a nearly 50 percent increase in bikes — by the end of 2019, there will be 3,000 Blue Bikes on the streets, up from 1,800 today — and add more than 100 new stations across Boston, Cambridge, Brookline and Somerville. The expansion will bring more service to underserved parts of the city, Bellows said.

“Communities like Mattapan, Dorchester, Roxbury, they’re going to get additional access to these bikes,” he said.

In a statement, Mayor Martin J. Walsh said bike-sharing has become critical to Boston transportation.

“The Hubway bike-share program began in the City of Boston in 2011 and quickly became integral to our transportation system,” Walsh said. “I am delighted to welcome Blue Cross Blue Shield as a partner as we further develop our bike-share program and I’d like to thank them for helping us to make this resource available to additional Boston residents in their own neighborhoods.”

After the city debuted the Hubway system in 2011, biking became more popular citywide and the rate of cycling injuries dropped, a 2016 study in the December issue of the American Journal of Public Health found.

The new Blue Bikes system will include an entirely new set of bikes, an improved mobile app and some new features, including a valet option at major transportation hubs. The valet service, for example, could mean a commuter to South Station would be able to drop their bike off at the valet station rather than trying to find a bikeshare dock with open spaces.

The BCBS sponsorship will replace a sponsorship strategy that allowed a variety of companies to pay to temporarily put their logo on the side of bikes. By switching to a single sponsor, Blue Bikes will follow in the footsteps of New York City’s Citi Bike and the San Francisco Bay Area’s Ford GoBike.

“We found the title sponsorship model works well because it’s a long-term commitment that provides a sustainable stream of support for the system and that allows it to be financially sustainable,” said Julie Wood, a spokeswoman with Motivate, the company that operates Blue Bikes and the bike-share programs in New York and the Bay Area.