The top Republican and Democrat on the Senate Finance Committee are asking the Medicare and Medicaid agency about federal spending on insulin and average out-of-pocket costs for beneficiaries as part of a larger probe into the rising cost of insulin.

The committee’s chairman, Chuck Grassley (R-Iowa), and ranking member Ron Wyden (D-Ore.) asked Centers for Medicare & Medicaid Services Administrator Seema Verma for data the agency has compiled on the impact of insulin costs and other diabetes-related costs, such as related health conditions and equipment, on federal spending, according to a letter released May 21.

“Even though insulin has been...