The Tax Bump Most Retirees Don’t See Coming

The standard advice is fine — until it isn’t

You’ve probably heard the conventional wisdom: spend taxable accounts first, then tax-deferred, then Roth. It’s simple, it’s widely taught, and it mostly makes sense — let the tax-advantaged accounts grow as long as possible.

The problem is what happens in the middle. You spend down your brokerage account over the first 7–10 years of retirement, paying little or no tax. Then one year it’s empty, and you flip to pulling everything from your traditional IRA. Suddenly you’re paying $4,000–$6,000 a year in federal tax where you were paying almost nothing. When RMDs kick in on top of that, it gets worse.

That’s the tax bump. It’s not dramatic enough to feel like a crisis in any single year, but over a 20-year retirement it compounds into real money — often $20,000 to $50,000 in lifetime taxes you didn’t need to pay.

What’s actually going on here

The red line is the conventional approach: drain your brokerage first, then switch entirely to IRA withdrawals. You get a nice quiet stretch in the beginning, then a wall of taxable income once you’re pulling from pre-tax accounts — right when RMDs might be piling on too.

The green line spreads withdrawals across account types so taxable income stays more even throughout retirement. You pay a little more tax in the early years, but you avoid the mid-retirement spike. Over a full retirement, the difference in this example is about $25,000 in lifetime taxes — purely from changing the order, not the amount.

And that’s just the starting point. The real savings come from actively managing which bracket you’re filling each year, coordinating with Roth conversions, and watching for secondary effects like Social Security taxation and Medicare surcharges (IRMAA).

Why most calculators can’t show you this

The typical retirement calculator asks for your total savings, a withdrawal rate, and a return assumption. It spits out a number and a success rate. It doesn’t model the fact that your $250K IRA and your $200K brokerage account and your $50K Roth are taxed completely differently — or that the order you tap them changes your tax bill every single year for decades.

To see the tax bump, you need a year-by-year projection that tracks each account separately, applies actual tax brackets, and models RMDs, Social Security taxation, and Medicare surcharges. Then you need to be able to compare alternatives against each other to find out which order — or combination of orders — actually costs you the least.

What we built to solve this

RetirementIQ models all five account types (cash, HSA, brokerage, pre-tax, Roth) as separate buckets with their own tax treatment. The projection engine runs year-by-year from now through end of plan, tracking withdrawals, taxes, RMDs, IRMAA, and Social Security taxation at each step.

The withdrawal order is fully customizable — you can reorder the default sequence and add age-based phases. Want to draw Roth-first during your pre-Medicare years to protect ACA subsidies, then switch back to the standard order at 65? That’s a phase. Want to pull pre-tax first in your early 60s to create room for Roth conversions? Also a phase.

But here’s the part that matters most for the person who read an article about withdrawal strategies and thought “ok, but which approach is best for me?”:

On top of that, the Roth Conversion Optimizer tests ~200 combinations of strategy, bracket, and age window to find the one that works best for your situation. It shows the Break-Even Tax Rate (BETR) — the future tax rate at which converting and not converting produce the same outcome — so you know exactly when conversions pay off.

And if you’re not sure where to start, the Guided Workflows tab walks you through it step by step. “Find and Fill Your Tax Valley” is the workflow that directly addresses this problem: it helps you identify your low-bracket window, test strategies to fill it, and verify the results in the Projection table and Monte Carlo simulations.

The short version

The order you withdraw from your accounts matters. A lot. The difference between “whatever runs out first” and a deliberate strategy is often tens of thousands of dollars over a retirement.

The articles explain the concept well. RetirementIQ lets you run it with your actual numbers — and then go further with Roth conversions, bracket management, IRMAA avoidance, and one-click strategy comparisons that would take hours in a spreadsheet.