Does the 4% Rule Work If I Retire at 55?
The 4% rule was built for a 30‑year retirement. Retire at 55 and the money may need to last 40 years or more. Here is where the rule came from, what longer‑horizon research found, and how early retirees make a plan sturdier.
Key takeaways
- Not reliably as a fixed rule. The 4% rule was tested on 30-year retirements; research on 40- to 60-year horizons finds lower starting rates are needed unless spending can flex.
- Bengen’s 1994 study found a 4% first-year withdrawal, raised for inflation, lasted at least about 33 years in every historical US period he tested, with 50–75% in stocks.
- Morningstar’s December 2025 report put the starting safe rate at 3.9% for a 30-year retirement with a 90% chance of success. Longer horizons push the rate lower.
- Flexibility changes the math. Guyton and Klinger (2006) found 5.2–5.6% starting rates held up over 40 years in their simulations, but only with rules that cut spending after bad years.
Does the 4% rule work for a 40‑year retirement?
It is less reliable over 40 years than over 30, and most research on long horizons points to a lower fixed starting rate or a flexible spending rule. The 4% figure was never a promise. It was the highest rate that survived the worst historical start dates over about three decades.
A retiree at 55 faces three extra problems: more years for a bad sequence of returns to do damage, more years of inflation, and a gap before Social Security and penalty-free access to some accounts. None of them makes early retirement unworkable. They mean the plan needs more slack.
Where did the 4% rule come from?
Three pieces of research are behind most of what you read about safe withdrawal rates.
| Study | What it tested | Main finding |
|---|---|---|
| Bengen, 1994 | US stocks and bonds, rolling historical periods | 4% plus inflation lasted at least about 33 years in every period, with 50–75% stocks |
| Trinity study, 1998 | US data 1926–1995, many stock and bond mixes | Higher rates failed more often as the horizon lengthened |
| Morningstar, Dec 2025 | Forward-looking return and inflation estimates | 3.9% starting rate for 30 years at a 90% probability of success |
Sources: Bengen’s paper, the Trinity study by Cooley, Hubbard and Walz, and Morningstar’s 2026 rate. All three assume a fixed real withdrawal. Real retirees tend to adjust.
What does research say about 40 to 60 years?
Longer horizons call for lower fixed starting rates. Early Retirement Now’s safe withdrawal rate series tested 30-, 40-, 50- and 60-year horizons on US data back to 1871 and found success rates at a given withdrawal rate fell as the horizon grew, while portfolios with a high stock share held up best over the longest periods.
Guyton and Klinger’s 2006 study used a 40-year horizon from the start. With at least 65% in stocks and rules that cut spending after bad years, starting rates of 5.2–5.6% passed their 99% confidence test. With 50% in stocks, the maximum fell to as low as 4.6%. The higher rates come with a cost: income that sometimes falls.
What does a lower starting rate mean in dollars?
Each half point of starting rate changes first-year income noticeably. Illustrative, on two portfolio sizes:
| Starting rate | On $1,000,000 | On $1,500,000 |
|---|---|---|
| 3.0% | $30,000 | $45,000 |
| 3.5% | $35,000 | $52,500 |
| 4.0% | $40,000 | $60,000 |
Sequence matters as much as the rate. Illustrative: someone who retired in January 2022 with $1.5 million, a 60/40 mix and a $60,000 yearly withdrawal would have had about $1.21 million after 2022, using the −15.8% return of the 60/40 mix in Exent’s hypothetical backtest. The same $60,000 was then 4.9% of the portfolio. The mix recovered over 2023–2025 in that backtest, but a retiree with no plan for that first year could easily have sold at the low. See the 60/40 strategy page.
How do early retirees bridge the years before 59½ and Social Security?
Most early retirees spend from taxable accounts and cash first, because withdrawals from IRAs before 59½ generally carry a 10% additional tax. The IRS exceptions list includes leaving an employer in or after the year you turn 55, but that exception applies to the employer’s plan, such as a 401(k), not to IRAs.
Withdrawals are often higher in the bridge years and fall once Social Security starts. The Social Security Administration raises benefits for each year you delay past full retirement age, up to 70, so some retirees spend more from the portfolio early to claim later. The order of accounts is covered in which account to withdraw from first.
How can I make a 40‑year plan sturdier?
- Start lower than 4% for fixed spending, or adopt written rules for when you will cut and when you may raise.
- Split spending into essentials and extras, and cover essentials with the most reliable income you have.
- Hold a cash or T-bill bucket for the first bear market, so year-one losses do not force stock sales.
- Keep enough in stocks for growth over four decades; research on long horizons favoured a meaningful stock share.
- Recheck the withdrawal rate every year: this year’s withdrawal divided by today’s portfolio, not the starting value.
How to check your early-retirement portfolio with Exent
- Upload a screenshot or file of each account (CSV, Excel, PDF or Google Sheet); no brokerage login, and multiple portfolios are supported.
- Exent replays the portfolio through 2008, 2020 and 2022 so you can compare the dollar loss with your yearly withdrawals.
- Try a different stock, bond and cash split in the what‑if simulator and compare drawdown, Sharpe and Sortino before you change anything.
Frequently asked questions
For fixed, inflation-adjusted spending over 40 years, research generally points to a lower starting rate. A 4% start can still work with flexible rules that cut spending after bad years.
There is no single number. Fixed-spending studies show lower rates as the horizon lengthens, while Guyton and Klinger found 5.2-5.6% held up over 40 years in their simulations only with spending cuts after bad years.
Financial planner William Bengen, in a 1994 paper that tested withdrawals against historical US returns. The 1998 Trinity study by three Trinity University professors popularised it.
Generally not. The age-55 exception applies to an employer plan such as a 401(k) when you leave that employer in or after the year you turn 55. IRA withdrawals before 59½ usually need a different exception.
Its December 2025 report put the starting rate at 3.9% for a 30-year retirement with a 90% probability of not running out, assuming fixed inflation-adjusted spending.
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Educational content, not investment advice. Examples are illustrative; past performance does not guarantee future results.