In recent months, Daschle has advocated for changes to the U.S. health system that are unpopular with sizable portions of the industry, including some physicians, drugmakers and insurance companies. Daschle has nonetheless prospered from a stream of income from the health sector, including $220,000 in speaking fees in the past two years, according to the ethics filing.

He also has been a trustee of the Mayo Clinic in Rochester, Minn. For part of the $2 million he received from the law firm Alston & Bird over the past two years, Daschle also reported that he gave "policy advice" to United Health, a conglomerate that sells insurance, helps the government administer Medicaid, advises drug companies and physicians and dispenses prescriptions.

The 12 organizations or companies that paid Daschle speaking fees, ranging from $12,000 to $30,000, included the National Association of Boards of Pharmacy and America's Health Insurance Plans, an influential trade group.

The Health Industry Distributors Association, a trade association representing medical product distributors, wrote to Daschle last week to express concerns about proposed Medicare changes and reminded him of the $14,000 speech he delivered at its conference last year.