Traditional vs. Roth: Not As Obvious As It Looks

Why Tax Timing, Retirement Income, and a New Catch-up Rule Matter

For years, the traditional-versus-Roth 401(k) decision has been framed as a simple tradeoff: pay taxes now or pay them later. For many investors in their peak earning years, that’s made the traditional (pre-tax) option feel like the obvious call. Take the deduction now. Save while your income is high. 

But 401(k)s have a way of making simple choices less simple over time. 

A large pre-tax balance can create more taxable income in retirement than some savers expect, especially once Social Security, Required Minimum Distributions (RMDs) and other income sources enter the picture. Add a SECURE 2.0 Act rule that now pushes certain higher earners’ catch-up contributions into a Roth account, and the old default starts to look less automatic. 

The decision is no longer just about a tax break. It’s about the income you may need to manage later, and whether using both account types may leave you better positioned.

Thinking Beyond “Tax Now or Later” 

At the most basic level, the difference between pre-tax and Roth 401(k)s is still about timing. 

Pre-tax contributions reduce your taxable income today, with withdrawals taxed as ordinary income later – a “tax later” strategy. Roth contributions are made with after-tax dollars and can be withdrawn tax-free in retirement – a “tax now” strategy. 

That foundational distinction still holds. But the SECURE 2.0 Act makes the decision feel less abstract, especially for investors who have long favored pre-tax contributions. Under the law, workers age 50 or older whose prior‑year wages exceeded $150,000 are required to make catch‑up contributions on a Roth basis. While final IRS regulations are effective in 2027, plans may implement the rule earlier based on a reasonable, good‑faith interpretation of the law. 

For some higher earners, this shift may be the first time Roth contributions become a meaningful part of their retirement savings. It would be easy to treat the new rule as a compliance detail and move on. But it also creates a reason to look more closely at how those contributions may work together over time, since the balance between pre‑tax and Roth dollars can shape future taxable income – particularly when Social Security and required distributions are involved. 

That question becomes more pressing in peak earning years, when the immediate tax benefit of pre-tax contributions is easiest to see. Reducing your taxable income today can lower your current tax bill and increase available cash, which helps explain why many high earners lean toward pretax accounts during these years. 

It is easy to assume retirement means a lower tax bracket. That is not always the case. Pre-tax dollars saved today become taxable income later, and those withdrawals don’t exist on their own. Social Security benefits, pensions and income from brokerage accounts can all add up, keeping taxable income higher than some retirees might expect. Future changes in tax rates could push your income into higher brackets than expected. 

RMDs add another layer. At a certain age, RMDs kick in for pre-tax accounts, requiring annual withdrawals that are taxed as ordinary income. Over time, these withdrawals can push total income higher, affecting how Social Security benefits are taxed and triggering income thresholds tied to Medicare premiums.

Roth accounts operate differently. Along with tax-free withdrawals in retirement, they aren’t subject to RMDs under current law. For some investors, Roth contributions can help limit how much future withdrawals add to taxable income. 

It’s not about avoiding taxes altogether. It’s about having more say over when and how income shows up. 

Why Many Investors Use Both... 

The old either-or view of Traditional versus Roth leaves out an important reality: many investors use both. 

Contributions can be split between account types over time, whether that means favoring one for a period and then the other later, or contributing to both over time. 

The appeal of pre-tax contributions during high-earning years is clear: an immediate tax deduction and more available cash. For many investors, it still plays an important role. But those pre-tax dollars become taxable income later. Adding Roth contributions as a complement, not a replacement, can change that equation. 

Building tax-free income alongside taxable income can make withdrawals easier to manage later, especially when Social Security and other income are already in the mix. The goal is not to choose a universally “better” option. It’s to understand how the two may work together to shape your income over time.

Why SECURE 2.0 Matters 

Under the SECURE 2.0 Act, certain high earners age 50 and older are required to make catch‑up contributions to a Roth account rather than on a pre‑tax basis, depending on prior‑year wages and plan design. While final IRS regulations take effect in 2027, some plans may adopt the rule earlier. For investors who have mainly focused on pre‑tax retirement savings, this may represent their first meaningful exposure to Roth contributions. Contact us with any questions you may have.