; and (ii) by a geographic adjustment factor to address regional affordability concerns. (3) Additional premium for certain D plans Nothing in this section shall preclude an individual from choosing a prescription drug plan which requires the individual to pay an additional amount (because of the inclusion of supplemental prescription drug benefits or because the plan is a more expensive plan, pursuant to section 1860D–13(a)(1)). In such case, the monthly premium under paragraph (1) shall be increased with respect to such individual. (d) Payment of premiums (1) Payment (A) In general Premiums for enrollment under this section shall be paid to the Secretary at such times, and in such manner, as the Secretary determines appropriate. (B) Payment of premiums by employers on behalf of employees An employer of an individual who enrolls under this section may make payments for the premiums for such enrollment on behalf of such individual pursuant to a process established by the Secretary. Such process shall ensure that enrollment under this section is the choice of the individual and not the employer. (2) Deposit Amounts collected by the Secretary under this section shall be deposited in the Medicare Buy-In Trust Fund established under subsection (e). (e) Medicare Buy-In Trust Fund (1) In general There is hereby created on the books of the Treasury of the United States a trust fund to be known as the Medicare Buy-In Trust Fund (in this subsection referred to as the Trust Fund ). The Trust Fund shall consist of such gifts and bequests as may be made as provided in section 201(i)(1) and such amounts as may be deposited in, or appropriated to, such fund as provided in this title. (2) Premiums Premiums collected under subsection (d) shall be transferred to the Trust Fund. (3) Incorporation of Provisions Subsections (b) through (i) of section 1841 shall apply with respect to the Trust Fund and this title in the same manner as they apply with respect to the Federal Supplementary Medical Insurance Trust Fund and part B,