Medco Health Solutions Inc. is trying to fight a giant retailer for the wallets of older U.S. residents.

Medco, Franklin Lakes, N.J., has announced that its Medicare Part D prescription plan, the Medco YouRx Plan, offers a better value than the widely publicized $4 generic program developed by Wal-Mart Stores Inc., Bentonville, Ark.

Wal-Mart is selling a 30-day supply of several hundred generic drugs for $4 per prescription.

Medco, a traditional pharmacy benefit manager, offers access to a 90-day supply of 2,000 generic medications for only $5, Medco says.

The $5 Medco plan mail-order pharmacy option offers access to a number of newer generic drugs, such generic cholesterol-fighting drugs that appear to be more effective than the cholesterol-fighting drugs in the Wal-Mart $4 generic program, Medco says.