1. Short title This Act may be cited as the Medicare at 50 Act . 2. Medicare buy-in option for individuals 50 to 64 years of age (a) In general Title XVIII of the Social Security Act ( 42 U.S.C. 1395c et seq.) is amended by adding at the end the following new section: 1899C. Medicare buy-in option for individuals 50 to 64 years of age (a) Option (1) In general Every individual who meets the requirements described in paragraph (3) shall be eligible to enroll under this section. (2) Part A, B, and D benefits and protections An individual enrolled under this section is entitled to the same benefits (and shall receive the same protections) under this title as an individual who is entitled to benefits under part A and enrolled under parts B and D, including the ability to enroll in a Medicare Advantage plan that provides qualified prescription drug coverage (an MA–PD plan) and including access to the Medicare Beneficiary Ombudsman under section 1808(c). (3) Requirements for eligibility The requirements described in this paragraph are the following: (A) Age The individual has attained 50 years of age, but has not attained 65 years of age. (B) Medicare eligibility (but for age) The individual is not otherwise entitled to benefits under part A or eligible to enroll under part A or part B but would be eligible for benefits under part A or part B if the individual were 65 years of age. (b) Enrollment and coverage periods (1) In general The Secretary shall establish enrollment and coverage periods for individuals who enroll under this section. (2) Coordination Such periods shall be established in coordination with the enrollment and coverage periods for plans offered under an Exchange established under title I of the Patient Protection and Affordable Care Act and plans under parts C and D. If the Secretary determines appropriate, the Secretary may expand such enrollment periods beyond the enrollment periods under such an Exchange or under parts C and D. (3) Beginning of coverage and special enrollment periods The Secretary