Grassley has conducted extensive oversight of financial relationships, especially among doctors who conduct research with the $24 billion awarded annually in federal grants by the National Institutes of Health. Institutions receiving these federal dollars are required to track financial relationships, but Grassley has found enforcement of those requirements often to be either lax or non-existent.

Grassley also has twice sponsored reform legislation that would require payments from the drug industry to be publicly reported. Senator Herb Kohl is the cosponsor of the pending Physician Payments Sunshine Act, S.301.