Attorney General Scott Pruitt will testify on at a hearing of the U.S. House Subcommittee on Energy Policy, Health Care and Entitlements, chaired by Rep. James Lankford of Oklahoma, regarding Oklahoma’s lawsuit challenging key provisions of the federal Affordable Care Act.

The congressional hearing is titled “Oversight of IRS’s Legal Basis for Expanding ObamaCare’s Taxes and Subsidies.” Oklahoma’s lawsuit argues that under the Affordable Care Act, the IRS is prohibited from imposing tax penalties on “large employers,” including local governments, in states that did not adopt state health care exchanges.