Wal-Mart Stores Inc. announced an expansion of its 4 U.S. dollars offer for some prescription drugs to 11 more states Thursday, saying its program will contribute to lowering the cost of health care in America.

The program, which offers a 30-day supply of some prescriptions at the discount price now covers 38 states. The world's largest retailer says it intends to be in all 50 states as early as January.

Wal-Mart tested the plan in the Tampa, Fla. area in September, then expanded the offer to 3,009 stores. States added Thursday were Idaho, Kentucky, Maine, Massachusetts, Nebraska, Oklahoma, Rhode Island, South Carolina, Utah, Washington and West Virginia.

The National Community Pharmacists Association, which represents non-chain pharmacies, and union groups have labeled the discounts a publicity stunt that covers only a small portion of the 8,700 generic prescription drugs approved by the Federal Drug Administration.

The Bentonville, Ark.-based retailer said the latest expansion also adds 17 varying dosages and forms, although no new drugs, to the discount list that now totals 331 prescriptions. That number is made up of 143 drugs in a variety of dosages and solid or liquid forms.

"No one should be denied access to the medications they need, and this program is a big step in moving our customers and communities toward access to affordable medicines," Wal-Mart Chief Executive Lee Scott said in a statement.

Wal-Mart said the list covers generic forms of 14 of the 20 most commonly prescribed drugs in the United States, based on a list of the top drugs compiled by the website www.rxlist.com.

Analysts said the main benefit for Wal-Mart was in drawing more shoppers into its stores who may come for prescriptions and then stay to buy in other departments.

Reaction from Wal-Mart's chain rivals has been mixed. After the earlier expansions, No. 2 discounter Target Corp. matched the discounts state-by-state. Other chains including Walgreen Co. said they would not change prices that they contend are already competitive, especially for people with insurance who only foot the cost of a co-pay.