Retirement Income Planning
The 4% Rule in Retirement: A Starting Point, Not a One-Size-Fits-All Strategy
Why the 4% rule can be a helpful starting point—and why retirement spending plans often need more flexibility.
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Article Summary
A clear overview of the 4% rule in retirement and why it should be used as a starting point—not a fixed strategy. Learn how factors like longevity, market conditions, income sources, taxes, and spending flexibility can shape a more personalized retirement withdrawal plan.
After years of saving, retirement brings a new question: How much can you safely spend each year without putting your long-term plan at risk?
A common answer is the 4% rule. It’s a useful rule of thumb, but it’s not a personalized retirement income plan.
For many retirees, the better approach is to use the 4% rule as a starting point, then adjust based on your time horizon, investment mix, other income sources, taxes, and willingness to be flexible.
What Is the 4% Rule?
The 4% rule is commonly traced back to financial planner William Bengen’s research, published in the Journal of Financial Planning in 1994. In that work, Bengen evaluated historical data and described a framework where a retiree starts with a 4% first-year withdrawal, then increases that dollar amount over time for inflation.1
You can think of it like this:
- Retire with $1,000,000
- Withdraw $40,000 in year one (4%)
- Increase that dollar amount in later years based on inflation
That simplicity is exactly why the 4% rule remains popular.
Why the 4% Rule Is Helpful, and Why It’s Limited
The rule can be a solid planning baseline, but retirement spending in real life is rarely that rigid.
Vanguard describes the 4% rule as a “dollar-plus-inflation” approach and notes one of its tradeoffs: it can ignore market conditions, which may lead to spending too much in weak markets or too little in strong markets. 2
Fidelity similarly presents a sustainable withdrawal rate as an estimate (often 4% to 5% in the first year, adjusted for inflation) and emphasizes that the “right” rate depends on factors such as longevity, inflation, market returns, retirement age, and investment mix. 3
In other words: the 4% rule is a planning shortcut, not a guarantee.
What a More Personalized Retirement Spending Plan Should Consider
1. How long your retirement may last
Longevity is one of the biggest variables in retirement planning.
The Social Security Administration’s actuarial life table (2022 period table, used in the 2025 Trustees Report) shows remaining life expectancy at age 65 of 17.48 years for men and 20.12 years for women in that table. Individual outcomes vary, of course, but it’s a reminder that planning horizon matters. 4
A longer time horizon generally means you may need a more conservative withdrawal approach, especially if you want a higher margin of safety.
2. Market risk early in retirement (sequence of returns risk)
The order of market returns matters, not just the average return.
T. Rowe Price notes that market declines in the first years of retirement can significantly affect portfolio longevity, especially when withdrawals are already underway. 5
That’s one reason a fixed rule may not be enough: two retirees with the same balance can have very different outcomes depending on when market downturns happen.
3. Your spending flexibility
One of the most powerful retirement tools isn’t a product or a formula, it’s flexibility.
Vanguard outlines a dynamic spending approach that combines a baseline withdrawal with guardrails (a floor and ceiling), allowing you to adjust spending when markets rise or fall. 2
This can help balance two goals:
- maintaining a reasonable lifestyle, and
- protecting your portfolio during down markets.
4. Other income sources
Your portfolio may not need to cover everything.
Fidelity notes that essential expenses (like housing, food, and healthcare) are often best paired with more stable income sources such as Social Security, pensions, or income annuities, while portfolio withdrawals can support more flexible spending. 3
This is an important mindset shift: the question isn’t only “How much can I withdraw?” but also “How much do I need my portfolio to cover after guaranteed income?”
5. Taxes and required minimum distributions (RMDs)
Retirement withdrawals are not just an investment decision, they’re also a tax decision.
The IRS states that required minimum distributions (RMDs) are the minimum amounts that must be withdrawn annually from certain retirement accounts, and that many account owners generally must begin taking them at age 73 (with some exceptions, including timing rules for certain workplace plans and retirement status). 6
The IRS also notes that failing to take RMDs correctly and on time can lead to penalties. 6
A Practical Way to Use the 4% Rule at OneDigital
Instead of treating 4% as a fixed answer, consider using it as Step 1:
Start with a baseline estimate
Use the 4% rule to get a rough sense of what your portfolio might support in year one.
Then pressure-test your number
Review it against:
- your retirement timeline
- your investment mix
- your essential vs. discretionary expenses
- your guaranteed income sources
- taxes and RMD timing
- your comfort with adjusting spending during down markets
Revisit the plan regularly
Retirement income planning works best when it is reviewed periodically, not set once and forgotten. Vanguard specifically highlights considering taxes, life expectancy, additional income sources, and your investment portfolio when choosing a withdrawal strategy. 2
The Bottom Line
The 4% rule can be a helpful way to start planning retirement income. But for most people, the best retirement spending strategy is not a strict formula, it’s a personalized plan that can adapt over time.
A strong retirement withdrawal plan should reflect:
- your goals,
- your timeline,
- your sources of income,
- and your willingness to adjust as life and markets change.
That’s how you move from a rule of thumb to a retirement strategy that fits real life.
Sources:
3 https://www.fidelity.com/viewpoints/retirement/how-long-will-savings-last
4 https://www.ssa.gov/oact/STATS/table4c6.html
6 https://www.irs.gov/retirement-plans/retirement-plan-and-ira-required-minimum-distributions-faqs
Investment advice offered through OneDigital Investment Advisors LLC.
The materials and the information provided are not designed or intended to be applicable to any person’s individual circumstances. These statements do not constitute an offer or solicitation in any jurisdiction. All included information and data are limited only to the inputs and other financial assumptions indicated.
Past performance is no guarantee of future results. All investments are subject to risk of loss, and there are no guarantees any investment or distribution strategy will work as intended.
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