The Medicare Access and CHIP Reauthorization Act of 2015 was signed into law by President Obama on April 16, 2015.
This law reduces the inflation adjustment, which causes more beneficiaries to be subject to higher Medicare premiums. This affects wealthier Medicare beneficiaries, who will have higher premiums for their Part B (physician services) and Part D (prescription drugs) in the future.
Medicare Part B and Part D premiums are based on one's tax bracket and specified by the following income thresholds:
Individuals with a modified adjusted gross income (MAGI) under $85,000 and couples under $170,000 are in tier 1 and pay only the standard Part B premium., which is $134 in 2018 and 2019.
For individuals earning $85,000 to $107,000 and married couples between $170,000 and $214,000 the Part B premium in 2018 and 2019 is $187.50.
Individuals earning more than $214,000 and couples above $428,000 pay more than three times the standard premium.
The income thresholds have been frozen until 2019, but will increase by about 2% in 2020. After 2020 it will be indexed to general inflation.