This final rule adopts, without change, the interim final rule with request for comments we published in the Federal Register on December 7, 2010, at 75 FR 75884. The interim final rule contained the rules that we apply to determine the income-related monthly adjustment amount for Medicare prescription drug coverage (also known as Medicare Part D) premiums. This new subpart implemented changes made to the Social Security Act (Act) by the Affordable Care Act. The interim final rule allowed us to implement the provisions of the Affordable Care Act related to the income-related monthly adjustment amount for Medicare prescription drug coverage premiums when they went into effect on January 1, 2011.