BENTONVILLE, Ark. — Wal-Mart Stores Inc. has added a new wrinkle to its generic drug program, offering a 90-day supply of about 300 generic prescriptions for $10, with free delivery by mail.

Wal-Mart is providing the free mail delivery program in 22 states in the Midwest and the Northeast, as well as in the District of Columbia. It applies not only to the 30-day supplies of eligible generic medications but also to other prescriptions filled at Wal-Mart pharmacies, the company points out.

Wal-Mart senior vice president and health and wellness division president John Agwunobi says this latest initiative is designed to bring affordable prescription medications to people who live in rural or urban areas not served by a Wal-Mart or a Sam’s Club store.

The rollout follows a successful pilot of the program in Michigan launched this spring.