You’re not powerless… if you run the AARP RMD Calculator, you can get a rough idea of what tax and IRMAA brackets you might end up in. For the hypothetical rate of return, put in your expected rate of return minus the inflation rate… I’d use 2.5% or 3% for inflation, so if portfolio thought to return 8%, then hypothetical rate of return 5%-5.5%. That will model RMDs assuming you make no withdrawls (you’re living off of Social Security and pension and taxable investments).
Once you’ve inflation adjusted the returns you can use current tax tables, because those also inflation adjust. So everything will match.
If you’re going to be pulling from the tax-deferred, the Flexible Retirement Planner is what you need.
As for me, in 2026 I’m going to pick up the pace of conversion / consumption of tax deferred but stop at the top of the 12% bracket (I hope that bracket survives the 2025 Congressional action), which is not far below the first IRMAA cliff, and about at the eligibility limit of the Leukemia and Lymphoma Society co-pay assistance program, a program my wife is going to try to get a grant from. So it’s a sweet spot. If I convert at that rate for a decade, then at my RMD age 75 I will have zero tax-deferred. All Roth and HSA and taxable, and I will not have over-paid to get there. Top of 12% bracket means 11% effective or average tax rate, so… that’s OK with me.
FYI this calculator is a “dinkytown” product, which Clark loves. He loves dinkytown.