"TurboTax adds back my partnership losses to my AGI to figure out MAGI."
Ignore that TurboTax FAQ. It's horribly misleading by in appropriately lumping all different types of modification to AGI for the many different purposes and Intuit refuses to correct or delete it. There is no add-back of the partnership losses in calculating MAGI for the purpose of a Roth IRA contribution and TurboTax does not do such an add-back.
