A Roth conversion is the process of moving funds from a traditional (pre-tax) IRA, 401(k), or other qualified plan into a Roth IRA. The converted amount is added to your taxable income for the year and taxed at ordinary income rates. In exchange, the money grows tax-free in the Roth, qualified withdrawals are tax-free, and Roth IRAs have no Required Minimum Distributions during the owner's lifetime.
Why Do a Roth Conversion?
Every dollar sitting in a traditional IRA or 401(k) carries a silent liability: a future tax bill. The government has never taxed that money, and it will, when you withdraw it, and in the form of Required Minimum Distributions (RMDs) starting at age 73. A Roth conversion lets you choose when you pay that bill, rather than leaving it to the IRS to decide for you.
The core case for conversion rests on tax diversification. Most pre-retirees have the majority of their savings in pre-tax accounts, a product of decades of 401(k) contributions. When RMDs begin, they arrive whether you need the income or not. Large RMDs push up your AGI, potentially taxing Social Security benefits, triggering IRMAA Medicare premium surcharges, and compressing your tax bracket flexibility. Converting some of those funds to Roth now, at known rates, eliminates that future forced income.
The math is straightforward: if your effective tax rate today is lower than your expected rate when RMDs begin, converting now wins. Roth assets then grow completely tax-free, and qualified distributions, including all earnings, are never taxed again. If Congress raises rates in the future (a real possibility given long-term fiscal projections), the Roth conversion becomes even more valuable in hindsight.
Beyond the pure numbers, a Roth IRA creates planning flexibility. Inherited Roth IRAs allow beneficiaries to take distributions tax-free. Roth assets don't count toward IRMAA income calculations in the year of withdrawal (only in the year of conversion). And having a tax-free bucket gives your advisor the ability to manage your income carefully year by year in retirement.
The Nevada Conversion Advantage
A Roth conversion is a federally taxable event, the converted amount is added to your ordinary income for the year and subject to federal income tax at your marginal rate. But state income tax is the crucial differentiator for Nevada residents.
Nevada has no state income tax. That means when you execute a Roth conversion, only the federal government takes a share. Compare this to a California resident converting the same amount: they pay federal income tax plus California's ordinary income tax, which runs from 9.3% at $100,000 of income up to 13.3% at the top bracket.
On a $100,000 Roth conversion, a Nevada resident pays $0 in state tax. A California resident converting the same amount pays $9,300 to $13,300 in California state tax alone, on top of whatever federal tax applies. Over a multi-year conversion strategy, those savings are substantial. A Nevada retiree who converts $100,000 per year for five years saves $46,500 to $66,500 in state taxes compared to an identical California retiree executing the same strategy.
This is one of the most underappreciated aspects of retirement planning for Nevada residents. The state's zero-tax environment doesn't just benefit wages, it benefits every conversion, every IRA distribution, and every capital gain. Nevada retirees executing Roth conversion strategies have a structural advantage that residents of high-tax states simply do not.
For clients who have relocated to Nevada from California, this advantage is particularly compelling. If you moved to Las Vegas and still hold a large traditional IRA, the window to convert at Nevada's effective state tax rate of 0% is an opportunity that deserves serious analysis.
The Optimal Conversion Window
Not all years are equal for Roth conversions. The best time to convert is typically the gap between retirement and age 73, when RMDs begin, often ages 60 to 72. During this window, income is frequently at its lowest point since early career: no wages, no RMDs yet, Social Security perhaps not yet claimed. This creates room to convert meaningful amounts while staying within lower federal brackets.
The tax bracket ladder approach is the most effective framework. Instead of converting everything at once, you fill up each bracket systematically. For example, if your income in a given year, from Social Security, a pension, or part-time work, places you in the 22% bracket with significant room remaining before reaching 24%, you convert exactly enough to reach the top of the 22% bracket, no more. The following year, you repeat the analysis.
The 22% and 24% federal brackets are the most common targets for Nevada retirees. Converting at these rates, with no state tax overlay, is generally considered favorable compared to deferring to a future environment where 32% or higher rates might apply, either because the tax code changes, or because your RMDs push you there automatically.
The window also matters because Social Security claiming strategy interacts with Roth conversions. If you delay Social Security to age 70 to maximize your benefit, the years before 70 often have very low income, an ideal time for larger conversions. Once Social Security begins, a portion becomes taxable income (up to 85%), which reduces the room available for tax-efficient conversions.
Working with a financial advisor to model year-by-year projections, accounting for Social Security, part-time income, RMD trajectory, and spending needs, is the most reliable way to identify the right conversion amount each year.
IRMAA Awareness
Medicare's Income-Related Monthly Adjustment Amount (IRMAA) is one of the most frequently overlooked costs of poorly planned Roth conversions. IRMAA adds surcharges to Part B (medical) and Part D (prescription drug) Medicare premiums for beneficiaries whose Modified Adjusted Gross Income (MAGI) exceeds certain thresholds, which are indexed annually.
In 2025, the first IRMAA tier begins at $106,000 for single filers and $212,000 for married couples. Exceeding the threshold adds roughly $740 per year in Part B surcharges per person at the first tier, rising to over $5,000 per year at the highest tier. These surcharges apply based on income from two years prior, so a conversion in 2025 affects your 2027 Medicare premiums.
This creates a critical planning constraint. A large one-time Roth conversion that saves $10,000 in income taxes may simultaneously trigger $1,500 in IRMAA surcharges annually for two years, eroding or eliminating the conversion's benefit. The goal is to convert as much as possible without crossing an IRMAA threshold unnecessarily.
The solution is annual modeling. Rather than converting in one large lump, a multi-year conversion plan analyzes each year's total income, Social Security, RMDs, investment income, and the planned conversion, against IRMAA thresholds. Conversions can be sized precisely to stay just below the next threshold. This requires attention to detail, but the premium savings over a 20-year retirement can be significant.
Partial vs Full Conversions
A full Roth conversion moves your entire traditional IRA or 401(k) balance into a Roth in a single transaction. For most people with meaningful retirement savings, a full conversion triggers an enormous tax bill in a single year, potentially hundreds of thousands of dollars in additional taxable income, almost certainly pushing income into the 32%, 35%, or even 37% federal bracket.
In most cases, this is not the right approach. Paying 37% to convert assets that would otherwise be taxed at 22% over time destroys value rather than creating it. Full conversions make sense only in specific circumstances: very low account balances, a year with unusually large offsetting deductions, or a situation where tax rates are expected to rise dramatically.
Partial conversions, converting only an amount that keeps total income within a target bracket, are the workhorse strategy for Nevada retirees. The typical approach is to determine how much room remains in the 22% or 24% bracket after accounting for all other income, then convert exactly that amount. This is repeated annually over a 5- to 12-year window, gradually shifting the balance of retirement assets from pre-tax to Roth.
The long-term outcome of a well-executed partial conversion strategy is a retirement portfolio with meaningful tax-free assets, reduced future RMDs, lower lifetime Medicare premiums, and more tax-efficient legacy planning for heirs. For Nevada residents, who bear no state tax cost on any year's conversion, this strategy is particularly powerful and worth initiating as early as the numbers support it.
Frequently Asked Questions
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There is no annual dollar limit on Roth conversions. You can convert any amount from a traditional IRA or 401(k) in a given year. However, the entire converted amount is added to your taxable income, so large conversions can push you into higher federal brackets and trigger IRMAA Medicare surcharges. Most advisors recommend a series of partial conversions over multiple years to manage the tax impact rather than converting everything at once.
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No. The Tax Cuts and Jobs Act of 2017 permanently eliminated the ability to recharacterize (undo) a Roth conversion. Prior to 2018 you could reverse a conversion by October 15 of the following year; that option no longer exists. Because conversions are now irreversible, timing your conversions carefully and not converting assets that may decline significantly in value is more important than ever.
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No. A Roth conversion is a taxable event but it is not earned income. You cannot use conversion income to justify making a new Roth IRA contribution. To make a Roth IRA contribution, you still need earned income (wages, self-employment income, etc.) and must be below the contribution income limits. Conversion and contribution are two separate and independent mechanisms for getting money into a Roth IRA.
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A Roth conversion increases your Adjusted Gross Income (AGI) in the year of conversion, which can cause more of your Social Security benefits to become taxable, up to 85% of benefits are taxable above certain income thresholds. This is a critical planning consideration: a large conversion in one year can trigger significant additional tax on Social Security income. Spreading conversions over multiple years and modeling total income carefully minimizes this effect.
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The 22% bracket is one of the most common Roth conversion sweet spots for Nevada retirees. If your traditional IRA balance is large enough that RMDs will eventually push you into the 24% or 32% bracket, paying 22% now to avoid higher rates later is generally a smart trade. Nevada's 0% state tax amplifies the benefit, you're paying only the federal rate with no state tax overhead. A qualified advisor can model your specific RMD trajectory to determine the right conversion amount each year.
Roth Conversion Action Checklist
Six steps to execute a Roth conversion strategically.
Related Guides
Ready to Model Your Roth Conversion Strategy?
Nevada's 0% state tax creates a genuine conversion advantage. Sasson Emambakhsh at Northwestern Mutual Las Vegas helps pre-retirees and retirees design year-by-year Roth conversion plans that minimize lifetime taxes and eliminate future RMD surprises.
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