WellPoint Inc. has announced that it plans to sell its NextRx pharmacy benefits management subsidiary to St. Louis, Mo.-based Express Scripts for $4.7 billion.

The deal includes consideration for the value of a future tax benefit for Express Scripts based on the structure of the transaction, the two companies announced in a statement.

Nationwide, WellPoint covers more than 35 million people. In New York, its subsidiary, Empire BlueCross Blue Shield, covers five million in 10 New York City metropolitan areas and surrounding counties, and its Anthem Blue Cross Blue Shield subsidiary covers Virginia and the Northern Virginia suburbs of Washington, D.C.

The NextRx PBM provides services to about 25 million Americans and manages more than 265 million adjusted prescriptions annually, according to WellPoint.

The transaction with Express Scripts, one of the largest PBM companies in the U.S., includes a 10-year contract to provide services to WellPoint once the deal closes.

George Paz, chairman and CEO of Express Scripts, said as the nation focuses on health car reform, the collaboration “represents a shared commitment to achieving optimal health outcomes while driving out wasteful spending.”

“As we apply our advanced understanding of consumer behavior to an additional 25 million members, and manage more than 750 million adjusted prescriptions annually, we will optimize the cross-selling of proven trend management tools such as generics, home delivery and specialty pharmacy,” Paz said in a statement.

Angela F. Braly, WellPoint’s president and CEO called the transaction “a unique and compelling opportunity to improve our integrated health benefits offerings to our members, while simultaneously delivering significant value to our shareholders.”

She added that the alliance of the two companies will create “an organization with greater resources and capabilities, which will provide members with more cost-effective solutions as well as access to state-of-the-art PBM services.”

The transaction is expected to close in the second half of this year.