Section 418.2005 - Purpose and administration(a) The purpose of the income-related monthly adjustment amount is for beneficiaries who have modified adjusted gross income above an established threshold to reimburse the Federal Government for a portion of the Federal subsidy of the Medicare prescription drug coverage. Persons who have modified adjusted gross income above the thresholds described in § 418.2105 will pay an income-related monthly adjustment amount in addition to the premium for their prescription drug coverage. The income-related monthly adjustment amount due will be determined based on the base beneficiary premium amount that represents 25.5 percent of the cost of the basic Medicare prescription drug coverage. The application of an income-related monthly adjustment amount results in an increase in the total amount that those who are affected pay for Medicare prescription drug coverage plans. A person who has modified adjusted gross income above the threshold amount will pay:(1) The Medicare prescription drug coverage plan monthly premium; plus(2) Any applicable increase for late enrollment or reenrollment;(3) An income-related monthly adjustment amount; and(b) The Centers for Medicare & Medicaid Services in the Department of Health and Human Services establishes rules for eligibility for Medicare prescription drug coverage and enrollment in Medicare prescription drug coverage plans, as well as premium penalties for late enrollment or reenrollment (42 CFR 423.30 through 423.56 ).(c) We use information from CMS about enrollment in Medicare prescription drug coverage plans to determine the records that we must send to the IRS.(d) We use information that we get from the IRS to determine if persons enrolled in Medicare prescription drug coverage plans are required to pay an income-related monthly adjustment amount. We also change income-related monthly adjustment amount determinations using information you provide under certain circumstances. In addition, we notify beneficiaries when the social security benefit amounts they receive will change based on our income-related monthly adjustment amount determination.