What is a sustainable retirement withdrawal rate, and why is it important?

• A. A fixed withdrawal rate of 6% of portfolio value annually.
• B. A starting point around 4% of the portfolio per year, adjusted for inflation and sequence of returns; guides longevity risk management.
• C. A withdrawal rate that ignores inflation and withdrawals are unlimited.
• D. A rate determined solely by life expectancy with no portfolio considerations.

Answer: (B)

A sustainable withdrawal rate is the amount you take from your retirement portfolio each year that you expect to last a multi-decade horizon, while accounting for investment returns, market volatility, and inflation. The best approach uses a starting point of about 4% of the portfolio in the first year, with withdrawals then increased each year by the inflation rate and moderated by how the portfolio performs, reflecting sequence-of-returns risk. This means you’re planning for real income over time, not just a single year, and you’re guarding against the risk that a few bad market years early in retirement could deplete assets if withdrawals are too aggressive. By tying withdrawals to inflation, you preserve purchasing power so spending power doesn’t erode. This balance helps manage longevity risk—trying to support spending for a long life without exhausting the nest egg. In contrast, a fixed, high 6% ignores future market swings and inflation; withdrawing without regard to inflation or portfolio performance risks depleting resources too quickly; and using life expectancy alone ignores how market performance and asset growth interact with spending, making it harder to sustain withdrawals over time.