· Listen
The Roth vs. Traditional question is asked thousands of times a day on the internet, and answered badly almost every time. The honest answer is shorter than the question, and the framework that produces it fits on a napkin.
The simple version
Roth: you pay tax on the money going in, then never again.
Traditional: you skip the tax going in, then pay tax on the money coming out in retirement.
The question is which tax rate is higher: yours now, or yours in retirement.
- If your tax rate now is lower than your expected tax rate in retirement, Roth tends to win.
- If your tax rate now is higher than your expected tax rate in retirement, Traditional tends to win.
- If they are roughly equal, the choice is closer to a coin flip, and other factors (estate planning, flexibility, employer match structure) become the tiebreakers.
The whole framework, in one comparison.
How it actually works
Same worker, same contribution, same growth, two tax treatments.
Scenario: $7,000 contributed to an IRA at age 30. Held for 35 years. Grows at 7% per year. Final balance: about $74,000.
Roth version: the worker paid tax on the $7,000 when earning it. Assume a 22% marginal rate. Tax paid: $1,540. The $7,000 went in. The $74,000 comes out tax-free at retirement. Total lifetime tax on this money: $1,540.
Traditional version: the worker took a $7,000 deduction when contributing, saving $1,540 in tax that year (at 22%). The full $7,000 went in. At retirement, the worker withdraws $74,000 and pays ordinary income tax on it. Assume a 12% marginal rate in retirement. Tax paid: $8,880. Net of the original $1,540 in tax savings, total lifetime tax on this money: $7,340.
In this scenario, Roth wins by about $5,800.
Now flip it. Worker at 22% now, expecting to be at 32% in retirement. Roth wins, and by more. Worker at 32% now, expecting to be at 12% in retirement. Traditional wins.
The framework is a comparison of two tax rates, separated by 30 to 40 years.
Who tends to lean Roth
- Early-career workers in lower brackets, expecting income growth.
- Workers expecting substantial retirement income from other sources (a pension, a paid-off rental property, a large taxable brokerage, Social Security).
- Workers who value not having Required Minimum Distributions. RMDs are required from Traditional 401(k)s and Traditional IRAs starting at age 73 under current law. Roth IRAs do not have RMDs for the original owner.
- Workers planning to leave the account to heirs. Roth accounts inherited by non-spouses have favorable tax treatment vs. Traditional under current law.
Who tends to lean Traditional
- Workers currently in high brackets (32%, 35%, 37%), with reasonable expectation of lower income in retirement.
- Workers who plan to relocate in retirement from a high-state-tax jurisdiction to a low-state-tax one. The deduction is taken at the high state rate now, the withdrawal taxed at the lower state rate later.
- Workers prioritizing maximizing current cash flow. The tax deduction frees up dollars for other savings goals.
The 'I don't know what my retirement tax rate will be' case
A common and defensible answer: split the difference. Contribute half to Roth, half to Traditional. The hedge guarantees that you do not get the decision 100% wrong in either direction.
This is also the most common professional default for younger workers who do not have strong reason to expect either rate environment.
A note on employer matches. Under current rules, employers offering a Roth 401(k) option can match into either a Roth or Traditional bucket depending on plan design. Older plans typically deposited the match into the Traditional side regardless of employee election. Check your Summary Plan Description (SPD) to see how yours handles it.
The Real Cost lens
The Real Cost of getting this wrong, on a maxed IRA contribution ($7,000 per year for 35 years at 7% real), is meaningful but not catastrophic. Across the full career, the dollar difference between the right and wrong choice is usually somewhere between 5% and 15% of the final after-tax balance, depending on how far apart the two tax rates are. On a $1 million balance, that is $50,000 to $150,000.
It is not life-or-death. It is real money. It is also one of the few decisions in personal finance where the right answer can shift based on tax legislation that has not been written yet, which is why hedging is a respected option.
What this lesson is NOT
This is not personalized tax advice. The right choice depends on your current bracket, your retirement income forecast, your state, your filing status, the structure of your employer match, and tax law that may change. Current law caps and rules are set by the IRS and Congress and are subject to revision. A CFP or CPA earns their fee on this decision for households with complex pictures.
The Roth vs. Traditional choice also does not have to be made once for life. You can change your contribution allocation any year. The decision is annually renewable.