; or (B) at any time while such individual is so eligible. (2) Coverage An individual enrolled under this section shall be eligible for benefits provided under this section beginning with the first day of the first month beginning after the date such individual so enrolls and ending on the earlier of the following: (A) The date on which such individual elects to terminate enrollment under this section. (B) The date on which such individual becomes entitled to benefits under part A or eligible to enroll for benefits under part B. (c) Premium (1) Amount of monthly premiums The monthly premium payable for coverage for a month under this section for an individual is equal to— (A) the monthly premium that would apply to such individual for such month under section 1839 if such individual were enrolled under part B