The Federal Housing Finance Agency (FHFA) is issuing a final rule on the process for validation and approval of credit score models by the Federal National Mortgage Association (Fannie Mae) and the Federal Home Loan Mortgage Corporation (Freddie Mac) (together, the Enterprises). The final rule defines a four-phase process for an Enterprise to validate and approve credit score models. The process begins with the Credit Score Solicitation (a solicitation by the Enterprises of applications from credit score model developers), followed by the Submission and Initial Review of Applications (an initial review by the Enterprise of submitted applications). The third phase is a Credit Score Assessment by the Enterprise, and the fourth phase is an Enterprise Business Assessment. The final rule establishes criteria for each of the four phases and includes required timing and notices for Enterprise decisions under the process.