The 401(k) Risk Many Californians Overlook: How RMDs Can Spike Your Taxes — and How to Plan
Required Minimum Distributions (RMDs) from traditional 401(k)s can unexpectedly raise federal and California taxes, trigger Social Security taxation and Medicare surcharges, and erode retirement income — planning like Roth conversions or strategic withdrawals can prevent costly surprises.
Key takeaways
- RMDs force taxable withdrawals from tax‑deferred accounts and can sharply increase both federal and California tax bills; see ICI FAQ.
- Large balances mean large RMDs: they can push you into higher tax brackets, tax more of your Social Security and trigger Medicare IRMAA; see Fidelity.
- Two primary defenses: phased Roth conversions and strategic withdrawals in low‑income years help shrink future RMDs; see T. Rowe Price.
Main content
Why 401(k)s work — and why they can become a problem
For many workers, a 401(k) is the easiest way to save: automatic payroll deductions, common employer matches and tax‑deferred growth make accumulation straightforward. That combination helps people build substantial balances over time (see Fidelity).
But with traditional 401(k)s, tax is deferred, not forgiven. Eventually the government requires minimum withdrawals — RMDs — calculated using your account balance and a life‑expectancy factor. If you have several employer plans, each plan’s RMD may be calculated separately and the rules can be complex (see ICI FAQ).
What are RMDs and when do they start?
RMDs are the minimum amounts the IRS requires you to withdraw annually from tax‑deferred retirement accounts once you reach the age set by law. Recent legislation (SECURE and SECURE 2.0) changed the start age for many savers, so the exact age may be 73 or 75 depending on your birth year. Missing an RMD can result in a very large penalty (see ICI FAQ).
How RMDs can hurt your retirement finances
RMDs affect more than just the money leaving your account. They can alter your tax profile and benefits:
- Higher tax brackets: Every dollar withdrawn from a traditional 401(k) is taxed as ordinary income. Large RMDs stacked on top of Social Security or other income can raise your marginal tax rate in retirement (Fidelity).
- More Social Security taxation: The IRS taxes Social Security benefits when your provisional income — adjusted gross income plus half your Social Security — exceeds thresholds. Big RMDs increase the chance that 50% or 85% of your benefits become taxable.
- Higher Medicare premiums (IRMAA): Medicare Part B and D premiums can include an income‑related monthly adjustment amount. Because IRMAA is based on income reported two years earlier, big RMDs can cause higher Medicare costs later.
- Less flexibility: If you don’t need the cash you’re forced to withdraw, you still pay income tax on it. Reinvesting after‑tax proceeds in a taxable account partially undoes tax‑deferred growth advantages.
How big balances get big problems
Long careers with steady contributions, employer matches and market growth make large 401(k) balances realistic. Disciplined savers can reach seven‑figure accounts — a good problem in terms of wealth, but one that can produce large mandatory taxable income when RMDs begin (see ICI FAQ; T. Rowe Price).
Two planning tools to reduce RMD pain
Two commonly used strategies can blunt RMD impact when implemented thoughtfully:
1. Roth conversions
A Roth conversion moves money from a traditional 401(k) or IRA into a Roth IRA. You pay income tax on the conversion now, but qualified Roth withdrawals are tax‑free and Roth IRAs do not have RMDs for the original owner. Converting gradually before RMDs begin can shrink future RMDs and move future growth into an account free of required withdrawals. Many savers roll 401(k) money into a traditional IRA upon leaving a job, then convert pieces each year (see T. Rowe Price; ICI FAQ).
2. Strategic withdrawals before RMDs
If you retire and expect a period of lower taxable income — for example, between leaving work and starting Social Security — that can be an ideal time to take larger withdrawals or do conversions. Using lower‑rate years to move money out of tax‑deferred accounts reduces amounts forced out later and helps avoid higher tax brackets, increased Social Security taxation and IRMAA tiers (see Fidelity).
Other options to consider
- Make Roth contributions at work when available — Roth 401(k) contributions grow tax‑free and can later be rolled into a Roth IRA to avoid RMDs (Fidelity).
- Model scenarios with a planner: Work with a financial planner to forecast projected balances and RMDs and to determine when conversions or withdrawals make the most sense.
- Stagger conversions: Spread conversions over years to avoid jumping into a higher tax bracket in any single year.
Implications for California
Economic impact
California taxes withdrawals from traditional 401(k)s as ordinary income. Large RMDs therefore increase state income tax bills in addition to federal tax, meaning Californians with big traditional balances could face unexpectedly high combined tax bills during RMD years. Given high housing and living costs in many parts of the state, after‑tax income matters for everyday budgets.
Political and policy consequences
Because California has higher top marginal tax rates than many states, federal RMDs plus state taxes raise the stakes for retirement tax planning. Policymakers and planners may emphasize Roth strategies and earlier planning to protect retirees’ buying power. Many who prioritize fiscal responsibility may view Roth conversions and careful withdrawal timing as private solutions rather than a case for changing tax policy.
Social effects
Higher taxes and Medicare surcharges can erode retirees’ incomes, potentially forcing some Californians to delay retirement, reduce discretionary spending or tap home equity. For readers who value personal responsibility, planning ahead — via Roth conversions and strategic withdrawals — preserves independence and reduces reliance on public programs.
Cultural relevance and practical steps for Californians
- Keep capturing employer matches: it’s effectively free compensation (Fidelity).
- Work with a tax advisor or planner: model federal and California impacts, including Social Security and IRMAA effects (see ICI FAQ).
- Consider phased Roth conversions: do conversions in lower‑income years — for example after leaving work but before Social Security starts — to spread out the tax hit and stay in lower brackets (T. Rowe Price).
- Use Roth payroll deferrals if offered: adding Roth contributions now shelters some future savings from RMDs and future taxes.
Bottom line: If you have a large 401(k) balance or expect long‑term savings growth, RMDs are a real planning risk. Early action — conversions, strategic withdrawals and careful forecasting — can protect both your tax bill and the retirement lifestyle you worked to earn.
Sources and guidance used in this report
- Fidelity: 401(k) benefits and basics
- Investment Company Institute (ICI): 401(k) FAQs
- T. Rowe Price: reasons 401(k)s make sense
- John Hancock: 5 benefits of investing in a 401(k)
- Smart Credit Union: importance of contributing to a 401(k)
- Empower: benefits of 401(k) plans
- Titan Wealth International: pros and cons
