THE METHODS OF MEANS TESTING AND WEALTH TAXATION ARE PRE-EXISTING CONDITIONS.

That is, a Medicare recipient still pays premiums even after he's no longer working and paying payroll tax.  For many people, that's invisible, as their Part B and Part D premiums come out of their "Social" "Security" benefits.  Show any kind of prudence, though, and you, too, will find out about the Income Related Monthly Adjustment Amount.

Let me quote from the notification the welfare state sends.

Each year to decide if you must pay IRMAAs, we use your Federal income tax information for the most recent tax year that is available.  However, we do not use any information that is more than three years old. We ask the Internal Revenue Service (IRS) for your tax filing status, your adjusted gross income, and your tax-exempt interest income.  We then add your adjusted gross income together with your tax-exempt interest income to get an amount that we call modified adjusted gross income (MAGI).  We compare your MAGI with the income thresholds set by Medicare law.

MAGI may include one-time only income, such as capital gains, the sale of property, withdrawals from an Individual Retirement Account (IRA) or conversion from a traditional IRA to a Roth IRA.  One-time income will affect your Medicare premium for only one year.

Of course it will, because there might be additional capital gains distributions or municipal bond interest for them to get their hands on next year.

That might make for a fun question at some presidential forum.  (With the Iowa caucus almost upon us, I might start paying closer attention.)  "Senator Sanders, what changes to the formula for calculating Modified Adjusted Gross Income and the Income Related Monthly Adjustment Amount do you include in your Universal Medicare plans?"