In the case of an individual who is entitled to monthly benefits under section 402 or 423 of this title, his monthly premiums under this part shall (except as provided in subsections (b)(1) and (c)) be collected by deducting the amount thereof from the amount of such monthly benefits. Such deduction shall be made in such manner and at such times as the Commissioner of Social Security shall by regulation prescribe. Such regulations shall be prescribed after consultation with the Secretary.

The Secretary of the Treasury shall, from time to time, transfer from the Federal Old-Age and Survivors Insurance Trust Fund or the Federal Disability Insurance Trust Fund to the Federal Supplementary Medical Insurance Trust Fund the aggregate amount deducted under paragraph (1) for the period to which such transfer relates from benefits under section 402 or 423 of this title which are payable from such Trust Fund. Such transfer shall be made on the basis of a certification by the Commissioner of Social Security and shall be appropriately adjusted to the extent that prior transfers were too great or too small.