I did Roth conversions last year with the plan for my income to not exceed the amount that would require me to pay Medicare IRMAA surcharges(I turn 65 in two years). After I received my final dividend payment in December 2023, I did a final Roth conversion to take my income to about $1000 below the predicted IRMAA limit. I just did my taxes and the Vanguard tax form shows my 2023 dividends to be $1200 more than what the Vanguard website shows. I called Vanguard and the representative told me that the dividend total shown on the website does not include Section 199A dividends that are included in the tax form. He told me the 199A dividends are produced by the VXUS ETF(international stock) that is the majority of my investments. The rep told me there is no easy way to know how much the 199A dividends will be until the tax form is released. I figure all I can do in the future is make sure my Roth conversions don't take me anywhere close to the IRMAA limit.