🪜The Trinity Study isn’t a finish line. It’s a framework.

Let's dive into The Trinity Study, the research behind the well-known 4% rule. This isn’t just another internet number.

It’s a study rooted in real market data, designed to answer a powerful question:

“How much can I safely withdraw from my retirement savings each year, without running out of money?”

And while this is just one piece of the financial rhythm puzzle, it’s a powerful one.

Let’s break it down fully, so you not only understand it, but know how to use it in a way that fits your life.

📚 What is the Trinity Study?

• Published in 1998 by three professors at Trinity University in Texas

• Tested various withdrawal strategies over historical market periods from 1926 to 1995

• Goal: To determine a “safe withdrawal rate” from retirement portfolios that would last 30 years

They ran simulations using different:

• Withdrawal rates (3% to 10%)

• Investment mixes (from 100% bonds to 100% stocks)

• Retirement lengths (20, 25, and 30 years)

🔍 What did they find?

The 4% withdrawal rate was the most successful across market conditions, particularly with portfolios that held at least 50% stocks.

This meant:

If you withdrew 4% of your retirement portfolio each year, adjusted for inflation, there was a 95%+ chance your money would last at least 30 years.

This led to the now-popular formula:
Annual expenses x 25 = retirement savings goal

💬 Wait: does it account for inflation?

YES.

The Trinity Study includes inflation-adjusted withdrawals.

That means if your retirement started in a year when bread cost $2, and 10 years later it cost $3, your withdrawal amount would increase to keep up with that change.

For example:

• Year 1: $40,000 withdrawal

• If inflation is 3%, then Year 2: $41,200

• This adjustment happens every year in their simulations

So yes: the 4% rule includes cost-of-living increases. That’s a big part of what makes it powerful (and conservative).

✅ Pros of the Trinity Study

1. It’s based on decades of real market data.
Not a guess. Not a hope. A history-tested framework built on nearly 70 years of U.S. market behavior.

2. It offers a clear starting point.
Instead of vague ideas like “save a lot” or “hope it’s enough,” it gives you a math-based goal you can plan around.

3. It adjusts for real life.
It includes recessions, bear markets, inflation: all the messiness we know exists.

4. It emphasizes sustainability.
It’s about not outliving your money and building a plan that can handle real ups and downs.

🛑 But here’s what it doesn’t do:

1. It assumes you’re invested and stay invested.
The 4% rule assumes a consistent portfolio: often 50–75% stocks, even during downturns. Emotionally, this is very hard for many people.

2. It assumes a 30-year retirement.
If you plan to step back earlier (and many nurses do), your retirement may last 35–40 years. That changes the math.

3. It’s based on U.S. historical performance.
It assumes U.S. markets will behave roughly the same in the future. That’s a big assumption.

4. It doesn’t account for nursing-specific variables.
Nurses often retire early due to physical or emotional burnout. We also face higher long-term health needs, especially if we’ve spent years caring for others without caring for ourselves.

🤔 Why do we teach this at NurseMoneyDate®?

Because this is one of the few research-backed tools that gives you a real number to work with.

We don’t teach the Trinity Study because it’s trendy.
We teach it because it gives you a starting point, something concrete enough to help you reverse engineer your retirement goal with clarity and strategy.

Instead of “I hope I’ve saved enough,” you can start asking:

• If I want to spend $60K/year in retirement, do I need $1.5M?

• Am I saving in a way that gets me there or not quite yet?

• Do I need to adjust, pause, or pivot?

This isn’t about fear. It’s about information.

But here’s what it does and doesn’t include:

✅ It does include inflation: your future withdrawals increase over time to keep up with rising costs
✅ It’s based on 30 years of retirement, which works for many, but not all

❗ It does not fully include health care costs, which are often higher for nurses retiring early or with physical burnout
❗ It does not include taxes on withdrawals or investment account fees
❗ It assumes you stay invested (50–75% in stocks), even during market dips

So while it’s a powerful tool, it’s also a simplified one.

We use it because it helps you stop guessing and start planning.
It gives you something real to aim for.

Not a fantasy. Not a finish line. Just a place to begin.