Do IRMAA income brackets adjust for inflation?

Yup

Here is what the Code of Federal Regulations says.

§ 418.1105. What is the threshold?

(a) The threshold is a level of modified adjusted gross income above which the beneficiary will have to pay the income-related monthly adjustment amount.
(b) From January 1, 2011 through December 31, 2019, the modified adjusted gross income threshold is $170,000 for individuals with a Federal income tax filing status of married filing jointly. The threshold is $85,000 for individuals with any other filing status.
(c) Starting on January 1, 2020, the threshold amounts will resume adjustment for inflation as required by section 1839(i)(5) of the Act. In each year thereafter, CMS will set all modified adjusted gross income threshold amounts for the following year by increasing the preceding year’s threshold amounts by any percentage increase in the Consumer Price Index rounded to the nearest $1,000. CMS will publish the amounts in the Federal Register in September of each year. Published threshold amounts will be effective January 1 of the next calendar year, for the full calendar year.

As of June 2022 the increase in the CPI is 9.1% You can find the IRMAA brackets for 2022 here.

Higher income beneficiaries do pay more for Parts B and D of Medicare based on their Modified Adjust Gross Income (MAGI).

IRMAA stands for Income Related Monthly Adjustment Amount.