20 C.F.R. § 418.3505
How would an increase, reduction or termination affect you?
(a) An increase in your subsidy means that you would be able to pay a lower premium to participate in the Medicare Part D prescription drug program. An increased subsidy may also result in a reduction in any deductible or copayments for which you are responsible.
(b) A reduction in your subsidy means that you would have to begin to pay a premium or a higher premium to participate in the Medicare Part D prescription drug program. You may also have to begin to pay a deductible and higher copayments or increase the amounts of these payments.
(c) A termination means that you would no longer be eligible for a subsidy under the Medicare Part D prescription drug program.