The company’s Pharmacy Saver program, to be formally announced Tuesday, will offer participants $2 out-of-pocket costs for 30-day supplies of 317 generic drugs at Kroger stores and 80 generics at Safeway pharmacies, among other options.

In addition, 90-day supplies of seven drugs will be available for $2 from UnitedHealth’s Prescription Solutions mail pharmacy and 28 drugs from the mail service will be available for $4 for a three-month supply. UnitedHealth hopes to add additional pharmacies to the program.

The move comes during the 2011 Me dicare open enrollment season, running Nov. 15 through Dec. 31, when beneficiaries choose which Me dicare health and drug plans to use next year. It also follows competitor Humana Inc.’s (HUM) announcement last month that it was joining with giant discount retailer Wal-Mart Stores Inc. (WMT) to offer a low-cost, co-branded Me dicare prescription-drug plan nationwide for 2011 that could save participants $450 a year in premiums, co-payments and cost shares.

UnitedHealth, the largest U.S. managed-care company by revenue and largest Me dicare Advantage plan concern by membership, said Pharmacy Saver wasn’t a response to the Humana-Walmart prescription-drug plan. Humana is the second-largest Me dicare Advantage player, although Me dicare accounts for a far larger share of Humana’s business than UnitedHealth’s.

“Economic pressures are putting a strain on many people’s budgets, including many seniors and other Me dicare beneficiaries living on fixed incomes. Pharmacy Saver is another example of our promise to provide our members with affordable prescription drugs,” said Tom Paul, chief executive of UnitedHealth’s UnitedHealthcare Me dicare & Retirement business. “We believe it’s important that our members have the flexibility to access their drugs in the way that’s most comfortable and convenient for them.”

The program, Paul said, “will help our members get the most value for their money in 2011.” Information about the program was available on a UnitedHealth website Monday.

Kroger and Safeway are two of the largest grocery chains in the U.S. Kroger, based in Cincinnati, operates more than 2,400 supermarkets and multidepartment stores in 31 states under two dozen brand names, plus convenience stores and other businesses. Pharmacy Saver pricing will be available in Kroger, Hilander, Fred Me yer, Food4Less, Ralphs and several other stores owned by Kroger.

Safeway stories participating in the program include Safeway, Randalls, Genuardi’s, Dominick’s, Tom Thumb, Vons and Carrs.

For members enrolled next year in UnitedHealth’s stand-alone Me dicare prescription-drug plans, the standard co-pay on many of the most common generics will range from $3.50 to $10. If members go to Safeway stores, however, they can receive reduced out-of-pocket costs on 109 drugs, including 80 available for $2 for a 30-day supply. Those taking simvastatin for high cholesterol can save up to $8 at Safeway, according to UnitedHealth.

Kroger stores will have 317 generics available for $2 for a 30-day supply. Me mbers who take one of the four blood-pressure medications most commonly used by the company’s Me dicare participants can save up to $8, UnitedHealth said.