Financial competition will help "simplify" the controversial Medicare prescription drug benefit as fewer companies provide the coverage or adjust their offerings, the health secretary said on Wednesday.

"The plans now know more about what consumers want, and they'll begin to simplify their offerings. We'll see a lot more standardization," Health and Human Services Secretary Mike Leavitt said.

"My guess is we'll find fewer people who are providing it (the benefit) because the market will identify the people who have done very well at it and those who have not done as well," he said, speaking at a Pensacola, Florida church event that was broadcast for reporters.

Under the voluntary program that began January 1, health insurers and other companies offer benefit plans under Medicare oversight.

Humana Inc., Aetna Inc., Medco Health Solutions Inc., UnitedHealth Group Inc., and WellCare Health Plans, Inc., among others, offer some of the roughly 40 plans available in many regions.

Pharmacies, including Wal-Mart Stores Inc., CVS Corp. and Walgreen Co., help co-promote some plans.

Consumer groups and other advocates have criticized the program for offering too many choices that make it confusing for most older and disabled Americans.

The agency has also come under fire for initial computer glitches that left thousands of beneficiaries without their medicines.

Still, Leavitt also said another 1.3 million seniors have voluntarily signed up since January 17, raising the total to 4.9 million people who have bought a stand-alone plan.

Overall, he said 25.4 million of Medicare's 42 million elderly and disabled have enrolled, Leavitt said.

Most of those were automatically signed up by their employers or by other government programs, including Medicaid, the joint federal-state insurance program for the poor.

Leavitt has said the agency expects 28 million to 30 million Medicare beneficiaries to join.