Year-End AMT Tax Planning: Strategies to Reduce Tentative Minimum Tax

Year-end AMT tax planning uses timing strategies to reduce a taxpayer’s tentative minimum tax before December 31. Effective techniques include deferring ordinary income, accelerating deductible expenses, managing incentive stock option exercises, and timing capital gains. Proper sequencing of these moves can cut AMT exposure or eliminate it entirely.

How AMT works and why timing matters

The Alternative Minimum Tax (AMT) is a parallel tax system that disallows certain deductions and includes certain preference items, calculating a minimum tax that the taxpayer may owe in addition to regular income tax. High-income individuals, especially those with deductions like state and local taxes (SALT), large charitable contributions, or exercise gains from stock options, are most at risk.

AMT is computed as follows:

• Start with taxable income
• Add back disallowed deductions (SALT, mortgage interest, miscellaneous items, depreciation preferences)
• Include preference items (long-term capital gains at full inclusion, ISO exercise gains)
• Subtract the AMT exemption (reduced based on income level)
• Apply the 26% or 28% AMT rate
• Compare to regular tax; pay whichever is higher

Because AMT is calculated separately and the exemption phases out as income rises, a taxpayer who can time income down or deductions up in December may stay below the AMT threshold or reduce the tentative minimum tax materially.

Timing income downward

The simplest lever is deferring income into January.

Discretionary bonuses. If your employer allows, defer a December bonus to January. This reduces current-year AMT income by the bonus amount and is often the cleanest move, especially if the bonus was not promised or expected in the original plan.

Consulting or self-employment income. Freelancers and consultants can delay invoicing or delay client payments if feasible. Invoice in January rather than late December; ask clients to delay payment by a few days if the relationship permits.

Investment income. Sell appreciated securities in January instead of December to defer the long-term capital gain (an AMT preference item) to the next year.

Restricted stock units. If you have RSUs vesting in December, inquire whether your employer can delay the vesting date or settlement by a few days into the new year. Some employers can accommodate this; others cannot due to trading windows or policy.

The risk with income deferral is that it delays the tax bill, not eliminates it. If your anticipated AMT is high, moving $100K of income to January simply pushes the problem forward unless you’re confident next year’s situation is better.

Accelerating deductions

Conversely, pull deductible expenses forward into the current year.

Charitable contributions. Make large gifts before December 31. A $50K donation to a qualified charity reduces AMT taxable income by $50K. But note: itemized deductions (including charitable gifts) are disallowed in full for AMT purposes unless they fall under the AMT charitable deduction exception. For 2025 and beyond, high earners using the standard deduction get no AMT benefit from charitable gifts unless they’ve bunched giving into a Donor-Advised Fund (DAF) in prior years. Confirm the current rules with a tax advisor.

Business expenses. If self-employed or running a side business, accelerate legitimate business expenses (office supplies, equipment, professional fees) into December. These reduce ordinary income and also reduce AMT income by the same amount.

Medical and dental expenses. If you have unreimbursed medical costs, prepay them before year-end if the service provider permits. Medical expenses are not deductible for AMT purposes, so this does not lower AMT tax—only regular income tax—but it may still help your overall tax picture.

Property taxes. Pay your Q4 estimated state income tax or property tax in December rather than January. These are disallowed for regular income tax SALT purposes (capped at $10K), and also disallowed for AMT; still, paying them in December instead of January does not change your AMT calculation but does reduce December’s cash balance.

Managing ISO exercise timing

Incentive stock options (ISOs) create AMT preferences. When you exercise an ISO, the difference between the fair market value (FMV) of the stock and the exercise price is an “adjustment” for AMT purposes—it increases your AMT taxable income, even though it’s not a cash event or a regular-income event. This preference can push you into AMT.

Exercise in January, not December. If you hold ISOs and are near the AMT threshold, deferring an exercise from December to January moves the preference income into next year, buying breathing room in the current year.

Exercise lower-strike options first. If you hold multiple ISO grants with different strike prices, exercising lower-strike options creates larger preference items (higher difference between FMV and strike). If deferring, identify which options to exercise later and which to exercise now; coordinate with anticipated AMT exposure.

Sell qualifying shares carefully. An ISO holding period requires 2 years from grant and 1 year from exercise to qualify as a “qualifying disposition.” A premature sale (non-qualifying) converts the gain to ordinary income and eliminates the AMT preference, which can actually reduce your AMT in some cases (trading a large preference for ordinary income). This is counterintuitive but worth analyzing: sometimes a forced early sale in December can lower AMT because it removes a large preference.

Diversify to reduce concentration. High-value ISOs in a single company create concentrated AMT exposure. Exercising a small batch and diversifying into a broad portfolio might seem like execution, but it’s also a hedge: if that single stock crashes, the AMT preference disappears next year when shares are worth less.

Accelerating capital losses and managing gains

Harvest capital losses. If you hold unrealized losses in your portfolio, sell them in December to offset capital gains and reduce adjusted gross income (AGI), which lowers AMT income. Long-term capital losses offset long-term gains dollar-for-dollar.

Defer capital gains. Conversely, if you’re sitting on large capital gains, defer them to January. A taxpayer in AMT today will benefit by moving gains to next year; a taxpayer in regular tax will carry forward a loss only if total losses exceed gains by $3K in the current year.

Pair sales strategically. If you must realize gains (e.g., rebalancing), consider whether selling an offsetting loser in December and the winner in January splits the gain timing and minimizes current-year AMT preference income.

Note: Capital gains create an AMT preference if they’re long-term gains; they are included in full when computing AMT income, whereas for regular tax purposes, long-term gains are taxed at preferential rates (0%, 15%, or 20%, depending on income level). This preference can easily push high earners into AMT.

Bunching or deferring large purchases

Depreciation and cost recovery. If you’re self-employed or own rental property, depreciation is an AMT preference item (especially bonus depreciation). Section 179 deductions and cost-recovery elections create preference items. Timing large capital purchases to January (rather than December) defers the depreciation preference to next year’s AMT calculation.

Trade-in timing. Similarly, if you’re acquiring depreciable assets, deferring the purchase to January postpones the preference impact.

Coordinating with estimated taxes and withholding

If you’re in AMT, your regular withholding or estimated tax payments may not fully cover AMT liability. Year-end adjustments to income and deductions can directly lower the balance due. Increasing withholding in December (via a W-4 change or additional estimated payment) covers the shortfall and avoids an April penalty, but does not reduce the underlying AMT tax—it just accelerates payment.

Estimating the benefit

Before taking action, estimate the impact:

1. Run two scenarios: one with the planned deduction or income deferral, one without.
2. Recalculate tentative minimum tax in each. Use IRS Form 6251 or a tax software tool.
3. Compare the total federal tax (regular + AMT). If deferring a $50K bonus saves $15K in AMT, but delays payment by one year, it’s worth it. If it saves $2K and you need the cash, it’s marginal.
4. Account for next year. If income will be lower next year, deferring this year’s income is beneficial. If next year’s income is expected to be equally high or higher, the deferral simply postpones the problem.

The limits of year-end planning

AMT has structural limits that timing cannot overcome:

High AMT exemption phase-out. The AMT exemption is $85,900 (single) / $133,200 (married filing jointly, 2024 figures) but phases out $0.25 per $1 of AMT income above $592,300 / $888,300. High-income earners may lose the entire exemption, making preference income fully taxable at the marginal AMT rate. Timing a few thousand dollars of income may help, but it won’t eliminate AMT if your income is far above the phase-out threshold.

Cascading preferences. Some taxpayers have multiple large preferences (ISOs, SALT, charitable gifts, depreciation) that together overwhelm timing moves. In such cases, AMT is almost unavoidable, and focus shifts to minimizing the damage (e.g., accelerating deductions across multiple years, or harvesting losses).

Wash sales and matching rules. Using loss harvesting to offset gains is valid, but the wash sale rule prevents you from repurchasing the same security within 30 days. Planning to “rebalance” into a similar asset requires care to avoid triggering the wash-sale rule.

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