Retirement Tax Mistakes That Can Become Expensive

Retirement taxes can be harder to predict than many people expect. A household may receive income from Social Security, a pension, an IRA, a 401(k), investments, part-time work, or the sale of a home—each with different tax treatment.

For residents of Rochester Hills, MI, understanding the interaction between federal rules and Michigan’s retirement-income rules can help prevent unexpected tax bills, penalties, and reduced cash flow.

Which retirement income is taxable?

The tax treatment depends on the source of the money, not simply on whether someone is retired.

Traditional IRA withdrawals, 401(k) distributions, pension payments, annuity income, interest, dividends, and many capital gains may be taxable. Roth IRA qualified withdrawals are generally tax-free, provided the account and distribution requirements are met.

Social Security is more complicated. A portion may become taxable when half of the benefits, plus other income and tax-exempt interest, exceeds federal thresholds. The base amounts are generally $25,000 for single filers and $32,000 for married couples filing jointly. Up to 85% of Social Security benefits may be included in taxable income at higher income levels.

Tax-exempt municipal bond interest can also affect the Social Security calculation, even though that interest is not generally subject to federal income tax itself. This is a commonly overlooked detail.

Why can a large IRA withdrawal create several problems?

A large withdrawal from a traditional IRA may increase taxable income in the year it is taken. That can lead to:

• A higher federal marginal tax rate
• More of the household’s Social Security becoming taxable
• Higher Medicare Part B and prescription-drug premiums through income-related adjustments
• A larger Michigan tax bill if the income does not qualify for a state subtraction
• A need for estimated tax payments

For example, taking an extra $50,000 from an IRA to remodel a home, replace a vehicle, or help an adult child may appear manageable based on the account balance. The tax effect can be much larger if the withdrawal pushes other income into a higher range.

A better approach is to estimate the tax impact before taking the distribution. Comparing one large withdrawal with several smaller withdrawals across different tax years may reveal a meaningful difference.

What happens if required minimum distributions are missed?

Required minimum distributions, often called RMDs, are mandatory withdrawals from many traditional retirement accounts once the applicable starting age is reached. The rules depend on birth year and account type, and they have changed in recent years.

Missing an RMD can result in a federal excise tax. The penalty may be reduced when the mistake is corrected promptly and reasonable steps are taken, but avoiding the error is much simpler than fixing it.

Common RMD mistakes include:

• Forgetting an old 401(k) or IRA held at another institution
• Assuming a Roth IRA has the same lifetime RMD rules as a traditional IRA
• Taking the first RMD late without understanding that two distributions may fall into the same tax year
• Failing to calculate separate RMDs correctly when multiple accounts are involved
• Overlooking inherited retirement-account distribution rules

Keeping a complete list of accounts and reviewing RMD requirements before year-end can reduce the risk of an unpleasant surprise.

Is withholding from a pension or IRA enough?

Not necessarily. Retirement income often does not have automatic withholding unless the account owner elects it.

Federal tax withholding may apply to pension payments and certain IRA distributions, but the default amount may not match the household’s actual tax liability. An eligible rollover distribution paid directly to an individual may also have mandatory withholding, which is not the same as the final tax owed.

A retiree who receives income from several sources should review total withholding rather than examining each payment separately. The household may need to adjust pension or IRA withholding or make estimated payments during the year.

This matters especially during the first year of retirement, when wages stop partway through the year but investment income and retirement distributions begin.

Can selling investments create a retirement tax trap?

Yes. Selling appreciated investments can create capital gains, and the tax result depends on the asset’s cost basis, holding period, and other income.

Selling a large investment position in one year may also affect the taxation of Social Security and Medicare premiums. Reinvesting proceeds does not erase the gain. Tax is generally based on the difference between the sale proceeds and the adjusted cost basis.

Records matter. Statements from older accounts may not show the complete cost basis, particularly after transfers, reinvestments, stock splits, or inherited assets. Before selling, confirm the basis and consider whether spreading sales across tax years would provide better control.

A related mistake is treating all investment income as equivalent. Qualified dividends and long-term capital gains may receive different federal treatment than interest, nonqualified dividends, or short-term gains.

How do Michigan rules affect retirees?

Michigan’s retirement-income rules do not always match federal rules. For tax years beginning in 2026, many qualifying retirement and pension benefits may receive a full Michigan subtraction, subject to the state’s requirements. The treatment can depend on the type of payment, the taxpayer’s circumstances, and whether the income qualifies as retirement or pension income under Michigan law.

Social Security has separate Michigan treatment, and recent legislation changes how certain taxpayers may claim both the Social Security deduction and the standard deduction during specified years.
A federal tax bill does not automatically indicate the Michigan result. Conversely, income that receives favorable Michigan treatment may still be taxable federally. Retirees should distinguish between federal adjusted gross income and Michigan taxable income when estimating their total liability.

What tax mistakes occur after moving or downsizing?

Selling a home, purchasing a smaller property, or moving between states can produce taxable events. A primary-home sale may qualify for a federal capital-gains exclusion if ownership and use requirements are met, but the exclusion is not automatic in every situation.
Taxable gains can also arise from:

• Selling a second home or rental property
• Converting a former residence into a rental
• Receiving insurance or relocation proceeds
• Selling property inherited from a family member
• Distributing retirement funds to cover moving or renovation costs

Rochester Hills households may also face significant property-related decisions as maintenance needs, accessibility concerns, and winter-related expenses change over time. The financial reason for a sale does not determine its tax treatment, so the numbers should be reviewed before a transaction is completed.

How can retirees avoid preventable tax surprises?

A practical annual review should include:

• Expected pension, Social Security, IRA, and investment income
• RMD amounts and deadlines
• Federal and Michigan withholding
• Capital gains and losses
• Charitable giving plans
• Medicare income-related premium thresholds
• The tax basis of investments and inherited property
• Changes in filing status after a spouse’s death

Charitable distributions directly from an IRA may be useful for eligible taxpayers who are at least 70½, because qualifying amounts can generally count toward an RMD while being excluded from adjusted gross income. The rules are specific, and the distribution must be handled correctly.

Tax planning is most effective before income is received, not after a tax return reveals the problem. A midyear review and another check before December ends can help a retiree decide whether to adjust withholding, time a distribution, realize gains or losses, or postpone a discretionary withdrawal.