• Subpart A [§ 423.1 - § 423.6] - Subpart A—General Provisions

• Subpart B [§ 423.30 - § 423.56] - Subpart B—Eligibility and Enrollment

• Subpart C [§ 423.100 - § 423.136] - Subpart C—Benefits and Beneficiary Protections

• Subpart D [§ 423.150 - § 423.186] - Subpart D—Cost Control and Quality Improvement Requirements

• Subpart E - Subpart E [Reserved]

• Subpart F [§ 423.251 - § 423.294] - Subpart F—Submission of Bids and Monthly Beneficiary Premiums; Plan Approval

• Subpart G [§ 423.301 - § 423.360] - Subpart G—Payments to Part D Plan Sponsors For Qualified Prescription Drug Coverage

• Subpart H - Subpart H [Reserved]

• Subpart I [§ 423.401 - § 423.440] - Subpart I—Organization Compliance with State Law and Preemption by Federal Law

• Subpart J [§ 423.452 - § 423.466] - Subpart J—Coordination of Part D Plans With Other Prescription Drug Coverage

• Subpart K [§ 423.500 - § 423.530] - Subpart K—Application Procedures and Contracts with Part D plan sponsors

• Subpart L [§ 423.551 - § 423.553] - Subpart L—Effect of Change of Ownership or Leasing of Facilities During Term of Contract

• Subpart M [§ 423.558 - § 423.638] - Subpart M—Grievances, Coverage Determinations, Redeterminations, and Reconsiderations

• Subpart N [§ 423.641 - § 423.668] - Subpart N—Medicare Contract Determinations and Appeals

• Subpart O [§ 423.750 - § 423.764] - Subpart O—Intermediate Sanctions

• Subpart P [§ 423.771 - § 423.800] - Subpart P—Premiums and Cost-Sharing Subsidies for Low-Income Individuals

• Subpart Q [§ 423.851 - § 423.875] - Subpart Q—Guaranteeing Access to a Choice of Coverage (Fallback Prescription Drug Plans)

• Subpart R [§ 423.880 - § 423.894] - Subpart R—Payments to Sponsors of Retiree Prescription Drug Plans

• Subpart S [§ 423.900 - § 423.910] - Subpart S—Special Rules for States-Eligibility Determinations for Subsidies and General Payment Provisions

• Subpart T [§ 423.1000 - § 423.1094] - Subpart T—Appeal Procedures for Civil Money Penalties

• Subpart U [§ 423.1968 - § 423.2140] - Subpart U—Reopening, ALJ Hearings and ALJ and Attorney Adjudicator Decisions, Council Review, and Judicial Review

• Subpart V [§ 423.2260 - § 423.2276] - Subpart V—Part D Communication Requirements

• Subpart W [§ 423.2300 - § 423.2345] - Subpart W—Medicare Coverage Gap Discount Program

• Subpart X [§ 423.2400 - § 423.2490] -

• Subpart Y [§ 423.2500 - § 423.2536] - Subpart Y—Transitional Coverage and Retroactive Medicare Part D Coverage for Certain Low-Income Beneficiaries Through the Limited Income Newly Eligible Transition (LI NET) Program

• Subpart Z [§ 423.2600 - § 423.2615] -