Ok the AGI and the Modified AGI are not always the same thing and there are at least a dozen different calculations of the modification depending on what the MAGI is being used for.
The MAGI used to calculate the Medicare Surtax is not something that the TT income tax program calculates ... the SSA office does this and you should have gotten a notice about the change.
https://www.medicareresources.org/medicare-eligibility-and-enrollment/what-is-the-income-related-mon...
