Section 155.1500 - Purpose and scope(a) This subpart sets forth the requirements of the IPPTA. The IPPTA is an initiative between HHS and the State-based Exchanges. These requirements are intended to: (1) Prepare State-based Exchanges for the planned measurement of improper payments.(2) Test processes and procedures that support HHS's review of determinations of advance payments of the premium tax credit (APTC) made by State-based Exchanges.(3) Provide a mechanism for HHS and State-based Exchanges to share information that will aid in developing an efficient measurement process.