Which account to draw from first

The frequently cited sequence is taxable first, then pre-tax, then Roth, on the logic that tax-advantaged accounts should compound as long as possible.

The refinement most planners apply is to stop treating it as an order and start treating it as an annual bracket-filling exercise: draw enough from pre-tax accounts each year to use up a target bracket, then meet the rest of the spending need from taxable or Roth sources.

This matters because leaving a large pre-tax balance untouched can produce very large required distributions later, sometimes pushing a household into a higher bracket permanently — often at the same time a surviving spouse begins filing as single.

Sequencing interacts with Medicare premium surcharges, capital-gains rates and state taxation. It is a coordination problem, which is precisely why it is usually worked out annually rather than decided once.