Income-Related Monthly Adjustment Amounts (IRMAA) are calculated by the Social Security Administration, not your Medicare Part D Prescription Drug Plan. They are not paid with premiums that go with a plan. An IRMAA Part B may still have to be paid if a Medicare Advantage plan is used to get Part A and B Original Medicare if the income qualifies. If a Medicare Advantage plan is used to get the Medicare Part D prescription drug coverage, this also applies.
If there is a late-enrollment penalty, it must continue to be paid in conjunction with the IRMAA adjustments as they are not the same thing. The late-enrollment penalty must continue to be paid for the entire duration of the time a person is covered by the Medicare program. IRMAA adjustments can be reevaluated as income changes. If income falls below the qualifying guidelines, IRMAA may be removed.