Since 2007, higher-income individuals and couples have been required to pay an additional income-related monthly adjustment amount (IRMAA) on their Medicare Part B premiums; a similar rule took effect in 2011 for Medicare Part D premiums. The ultimate impact can potentially be significant; although only a small number are affected, those at the highest income levels in 2015 (used to determine premiums in 2017) will see their Medicare Part B premiums rise from a base of $134.00/month up to $428.60/month. (Notably, though, those eligible for the "hold harmless" rules will have Part B premiums capped at $109.00/month for 2017.) In addition, Part D premiums will cost as much as an extra $72.90/month in addition to the base rate of the plan itself, under the IRMAA rules.
Although the higher premium amounts are a cost, because they're determined based on income and may change from year to year, they effectively equate to an "indirect tax" in the form of a higher burden on higher income levels. In turn, this means that the income thresholds for Medicare Part B and D premiums should itself be treated as a "tax bracket" that can be planned and managed around, as a form of proactive income tax planning. Strategies that might create income, or defer income resulting in a greater concentration down the road, must be evaluated for not only their outright tax consequences, but their indirect tax consequences in the form of higher Medicare premiums!
