Compensation Awards and Tax Planning: What Employees Need to Know

Introduction

Equity compensation and tax-advantaged benefit accounts are two of the most powerful and most frequently misunderstood elements of modern compensation packages. Whether you are an employee receiving your first stock option grant, a business owner designing benefit programs, an HR professional advising your team, or a financial professional helping clients optimize their tax position, a solid working knowledge of these instruments can mean the difference between maximizing your wealth and leaving significant money on the table.

This guide covers five major categories of compensation-related tax issues for 2025: stock options (Incentive Stock Options, Nonstatutory Stock Options, and Employee Stock Purchase Plans), equity grants (Restricted Stock Units, Restricted Stock Awards, and Stock Appreciation Rights), Flexible Spending Accounts (FSAs) and Health Savings Accounts (HSAs), the Kiddie Tax, and the Alternative Minimum Tax (AMT). Each section explains what the instrument is, how it is taxed, what planning opportunities exist, and what pitfalls to avoid.

All figures reflect 2025 IRS guidelines as published in IRS Revenue Procedures and Publications 969 and 525.

Part 1: Stock Options — ISOs, NSOs, and ESPPs

Stock options give recipients the right, but not the obligation, to purchase shares of company stock at a fixed price (the exercise price or strike price) at a future date. The applicable tax rules vary significantly based on the type of option, the timing of transactions, and whether specific holding periods are satisfied.

Incentive Stock Options (ISOs)

ISOs are the most tax-advantaged form of stock option available. Governed by IRC Sections 421 through 424, they may only be granted to employees and not to consultants or non-employee directors. The total fair market value of ISO shares that become exercisable in any single calendar year is capped at $100,000 per employee, measured at the grant date. Any amounts above this cap are automatically treated as nonstatutory options.

How ISOs Are Taxed

At Grant: No tax consequences for the employee and no employer deduction.

At Exercise: No regular income tax is owed. However, the spread (the difference between the stock’s FMV at exercise and the exercise price) is an AMT preference item. Exercising and holding ISOs can trigger the Alternative Minimum Tax even though no regular income tax is due.

At Sale, Qualifying Disposition: If the employee holds the stock for at least two years from the grant date and at least one year from the exercise date, the entire gain is taxed as a long-term capital gain at the preferential 0%, 15%, or 20% rate.

At Sale, Disqualifying Disposition: If either holding period is not met, the bargain element (FMV at exercise minus exercise price) is recognized as ordinary compensation income on the employee’s W-2. Any additional gain above that FMV is treated as a capital gain.

Basis: The regular tax cost basis equals the exercise price paid plus any amount paid for the option itself.

If the Option Lapses: The employee has a capital loss equal to any price paid to acquire the option.

The ISO $100,000 Annual Vesting Cap

The ISO designation only applies to options with an aggregate grant-date FMV up to $100,000 that become exercisable in a single calendar year. Any value above that limit is automatically reclassified as an NSO and taxed accordingly. Employees with large option grants should monitor this annual limit carefully.

Post-Termination Exercise Window

Upon leaving a company, employees typically have only 90 days from their last day of employment to exercise ISOs before they automatically convert to nonstatutory options. Missing this deadline permanently eliminates the ISO tax advantage and is a deadline that is easy to overlook during a job transition.

ISO and the AMT

Exercising ISOs and holding shares past year-end creates an AMT preference item equal to the spread. For employees with large ISO exercises, this can result in significant AMT liability even when no cash has been received from a sale. When you pay AMT in an ISO exercise year, the excess creates a Minimum Tax Credit (Form 8801) that carries forward indefinitely and offsets future regular tax liability. AMT paid on ISO exercises is best understood as a temporary prepayment of future taxes rather than a permanent double taxation.

ISO Planning Strategies

Spreading exercises over multiple years helps manage annual AMT exposure rather than concentrating all ISO exercises in a single year. Exercising when the spread is small, such as when the stock trades near your exercise price, minimizes the AMT preference item. Exercising early in the tax year provides maximum visibility into your total tax picture before year-end. After exercising ISOs, you will carry two separate cost bases: a regular tax basis (the exercise price) and an AMT basis (the exercise price plus the spread). Keeping careful records of both is essential for calculating taxes accurately when you eventually sell. Before any exercise, ask your tax advisor to calculate the gap between your regular tax and your tentative minimum tax. This figure tells you exactly how much spread you can absorb without triggering AMT.

Worked Example: ISO Qualifying Disposition

An employee receives an ISO grant in January 2023 to purchase 1,000 shares at $10 per share. She exercises in February 2024 when the FMV is $40. She sells in March 2026 at $70 per share.

At exercise in February 2024:

Regular tax = $0.

The AMT preference item = ($40 – $10) × 1,000 = $30,000, which is added to AMTI.

For AMT purposes, the basis becomes $40 per share at exercise.

At sale in March 2026:

More than two years have passed since the grant date and more than one year since the exercise date, so this is a qualifying disposition.

Total gain = ($70 – $10) × 1,000 = $60,000, all of which is taxed as a long-term capital gain.

For AMT purposes, the basis was $40 at exercise.

The AMT gain = ($70 – $40) × 1,000 = $30,000.

This results in a negative AMT adjustment, which may allow prior AMT credits to be used.

Nonstatutory (Non-Qualified) Stock Options (NSOs/NQSOs)

NSOs may be granted to employees, non-employee directors, independent contractors, consultants, and advisors. There is no annual vesting cap and no 90-day post-termination exercise requirement. The tradeoff is less favorable tax treatment compared to ISOs.

NSOs Without a Readily Determinable Value at Grant (Most Common)

At Grant: No tax event occurs.

At Exercise: The bargain element, which is the FMV of stock at exercise minus the exercise price, is recognized as ordinary compensation income. This amount is subject to federal and state income tax, Social Security (FICA), and Medicare taxes. Employers are required to withhold on this amount as wages and report it on Form W-2.

Basis After Exercise: The employee’s basis equals the FMV at exercise (exercise price plus ordinary income recognized).

At Sale: Any subsequent gain or loss from the FMV at exercise is treated as a capital gain or loss. Gains are short-term if the shares are held one year or less and long-term if held more than one year.

If the Option Lapses: The employee has a capital loss equal to any price paid for the option.

Important Note: Unlike ISOs, the bargain element on NSO exercise is subject to Social Security and Medicare taxes. For 2025, the Social Security wage base is $176,100. Income above this threshold remains subject to the 1.45% Medicare tax and the additional 0.9% Medicare Tax on wages above $200,000 for single filers and $250,000 for married filing jointly.

NSOs With a Readily Determinable Value at Grant

When an NSO is actively traded on an established securities market, ordinary income is recognized at the grant date (FMV of the option minus any amount paid). No additional income is recognized at exercise. The basis equals the exercise price plus income recognized at grant. If the option lapses, the employee has a capital loss for the value previously taxed.

Employer Deduction

When an employee recognizes ordinary income on an NSO exercise, the employer receives a corresponding tax deduction in the same year. In the case of ISOs exercised as qualifying dispositions, there is no employer deduction available. This is one reason many companies favor NSOs for large or broad-based equity grants.

NSO Planning Strategies

Timing exercises to coincide with lower-income years reduces the ordinary income tax cost, since NSO exercise income is treated as ordinary income. Exercising before a large RSU vest or anticipated bonus can help manage bracket exposure. A same-day or cashless exercise is appropriate when stock price exposure is not desired, since the entire bargain element is recognized as ordinary income with no capital gains component. For employees who wish to hold the shares after exercise, any post-exercise appreciation is taxed as a long-term capital gain after a holding period exceeding one year from the exercise date. The bargain element at exercise remains ordinary income regardless of how long the shares are subsequently held.

Employee Stock Purchase Plans (ESPPs)

ESPPs allow employees to purchase company stock, typically at a discount of up to 15% off market price, through after-tax payroll deductions during an offering period. Many plans include a look-back feature under which shares are purchased at the discount applied to the lower of the stock price at the start or end of the offering period. The annual purchase limit for qualified ESPPs is $25,000 of FMV of stock, measured at the offering date, per employee per year.

Qualifying vs. Disqualifying Dispositions

To qualify for favorable tax treatment, employees must hold their shares for at least two years from the offering date and at least one year from the purchase date.

Qualifying Disposition: The ordinary income component is capped at the lesser of (1) FMV at sale minus purchase price or (2) FMV at the offering date minus purchase price. Any remaining gain above the ordinary income component is taxed as a long-term capital gain.

Disqualifying Disposition: The full bargain element at purchase (FMV at purchase minus price paid) is ordinary income reported on Form W-2. Any additional gain from the purchase-date FMV to the sale price is treated as a capital gain, either short-term or long-term depending on the holding period.

Sale at a Loss (Disqualifying): No ordinary income is recognized when shares are sold below the purchase price. The resulting loss is a short-term or long-term capital loss depending on the holding period from the purchase date.

ESPP Planning Strategies

Qualifying dispositions should be the goal whenever possible, as the tax savings relative to a disqualifying disposition can be substantial when the discount is large and the stock has appreciated. Holding ESPP shares indefinitely creates concentrated single-stock risk. Once holding periods are met, diversification is generally advisable. Employees should track offering dates carefully, as the two-year clock begins on the offering date and not the purchase date. Confusing these two dates is a common error that can result in inadvertent disqualifying dispositions.

Part 2: RSUs, Restricted Stock Awards, and Stock Appreciation Rights (SARs)

RSUs and restricted stock awards do not require the employee to purchase anything. The employer promises to deliver stock once vesting conditions are met. SARs settle entirely in cash based on stock price appreciation.

Restricted Stock Units (RSUs)

An RSU is a contractual promise by the employer to deliver a specified number of shares once vesting conditions are satisfied. Unlike options, RSUs retain value as long as the underlying stock has value. There is no underwater risk and no purchase required on the part of the employee.

Vesting Structures

Time-Based (Single-Trigger): Shares vest over a defined period, typically four years, on annual, quarterly, or monthly schedules. This structure is common among public companies.

Performance-Based (Double-Trigger): Vesting requires both a time condition and a performance milestone, such as an IPO, acquisition, or the achievement of a financial target. This structure is common at pre-IPO private companies. When both triggers are satisfied simultaneously at an IPO, a large block of RSUs can vest at once, concentrating a significant amount of income in a single tax year.

How RSUs Are Taxed

At Vesting: The FMV of shares on the vesting date is recognized as ordinary compensation income, reported on Form W-2, and subject to federal income tax, state income tax, Social Security tax up to the $176,100 wage base for 2025, and Medicare taxes. The employee’s cost basis in the shares equals the FMV on the vest date.

At Sale: Any gain or loss after vesting is treated as a capital gain or loss. Gains on shares sold within one year of vesting are short-term and taxed at ordinary income rates. Gains on shares sold more than one year after vesting are long-term and taxed at 0%, 15%, or 20%.

Note: RSUs are not subject to the Alternative Minimum Tax. RSU income is treated identically under both the regular tax system and the AMT, which simplifies planning considerably compared to ISO-heavy compensation structures.

The Supplemental Wage Withholding Trap

When RSUs vest, employers withhold using the supplemental wage rate: 22% federal withholding on the first $1 million of supplemental wages per year and 37% on supplemental wages above $1 million. For employees in the 32%, 35%, or 37% federal brackets, the default 22% withholding rate significantly underestimates actual tax liability. This can result in a substantial tax balance due at filing, along with potential underpayment penalties.

Example: An employee earns $300,000 in salary and vests $200,000 in RSUs. The employer withholds 22% federal, or $44,000. However, the employee’s actual marginal federal rate on that vest income is 35%, creating a $26,000 federal tax shortfall before state taxes are considered.

To address this shortfall, employees should request higher supplemental withholding from their employer if the plan permits it, make quarterly estimated tax payments in anticipation of RSU vest income, or plan to sell additional vested shares to generate the cash needed to cover the tax liability.

The Two Costliest RSU Tax Mistakes

Incorrect Basis Reporting: Brokers sometimes report full sale proceeds on Form 1099-B without reflecting the vest-date cost basis, making the entire sale amount appear to be a taxable gain. Employees must correctly report the vest-date FMV as their cost basis on Form 8949 and Schedule D. Retaining all vest confirmations and reconciling them against the basis reported on the 1099-B each year is essential.

Wash Sale Rule at Year-End: Selling RSU shares at a loss near year-end while new RSU shares vest within 30 days before or after the sale (a common occurrence on quarterly vesting schedules) may trigger the wash sale rule and disallow the loss. Year-end sales should be planned with this timing in mind.

Hold vs. Sell After Vesting

Sell at Vesting: Selling immediately after vesting minimizes capital gain exposure since the sale price approximates the basis. It also eliminates single-stock concentration risk and represents the most tax-efficient and risk-averse approach.

Hold for Long-Term Capital Gain: Holding shares for more than one year after vesting converts post-vest appreciation from ordinary income tax rates (up to 37%) to long-term capital gains rates (up to 20%). This approach increases single-stock concentration risk and requires a deliberate assessment of the downside exposure.

Timing Consideration: If RSUs vested eleven months ago and a sale is being considered, it is worth running the numbers before executing. Waiting one additional month may convert short-term gains taxed at up to 37% into long-term gains taxed at up to 20%. When the risk of a price decline during that period is manageable, the tax savings from waiting may be substantial.

Restricted Stock Awards (RSAs) and the Section 83(b) Election

A restricted stock award transfers actual shares to the employee on the grant date but includes restrictions that prevent sale until the vesting date. The default tax treatment mirrors RSUs: ordinary compensation income is recognized on the vesting date based on the FMV of the shares at that time. However, restricted stock award recipients have one option that RSU recipients do not: the Section 83(b) election.

Under IRC Section 83(b), an employee may elect to include the FMV of the stock on the grant date as ordinary compensation income rather than deferring income recognition to the vesting date. This election must be filed with the IRS within 30 days of the grant date, and a copy must be attached to the tax return for that year. No extensions are available.

The 83(b) election is most beneficial when the stock’s FMV is very low at grant, such as just after company formation when the 409A valuation is minimal, and the stock is expected to appreciate significantly before vesting. In that scenario, the election results in a small amount of ordinary income being recognized upfront, while most future appreciation is treated as long-term capital gain rather than ordinary income.

Important Warning: If the employee makes the 83(b) election and subsequently forfeits the stock by leaving the company before vesting, no deduction is allowed for the taxes already paid on the grant-date value. The only available recovery is a capital loss for any price paid for the stock itself. This election should never be made without a thorough understanding of forfeiture risk and confirmation that the upfront tax can be paid without financial hardship.

Stock Appreciation Rights (SARs)

A SAR gives the employee the right to receive a cash payment equal to the appreciation in the company’s stock price from the grant date to the exercise date. No purchase is required. The employee simply receives the increase in value as a cash payment. SARs are especially common at private companies where stock liquidity is limited, as they provide a guaranteed cash payout without requiring the employee to locate a buyer for shares.

When a SAR is exercised, the full cash payment is treated as ordinary compensation income in the year of exercise, regardless of how long the SAR was held before exercise. There is no opportunity for long-term capital gain treatment under any circumstances, which makes SARs the least tax-efficient form of equity compensation from the recipient’s perspective.

The ordinary income equals the FMV at exercise minus the FMV at grant, multiplied by the number of SARs exercised. This amount is included on Form W-2 and subject to all applicable federal and state income taxes and payroll taxes.

Planning Note: Because SAR proceeds are always treated as ordinary income, the primary tax planning lever is the timing of exercise. Exercising in a year when the employee’s marginal tax rate is lower, such as before a large RSU vest, a year-end bonus, or during a period of reduced income, can reduce the overall tax burden.

Part 3: Flexible Spending Accounts (FSAs) and Health Savings Accounts (HSAs)

Employer-sponsored health benefit accounts allow employees to pay for qualified medical, dental, and vision expenses using pre-tax dollars, thereby reducing both federal income tax and FICA taxes. Although FSAs and HSAs serve similar purposes, they operate under substantially different rules, and understanding those differences is critical to maximizing their value.

Health Flexible Spending Accounts (FSAs)

An FSA is an employer-established account that allows employees to redirect a portion of their salary on a pre-tax basis toward eligible healthcare expenses. Employees elect their annual contribution amount during open enrollment and must commit to that amount at the start of the plan year.

2025 FSA Key Numbers:

Annual Health FSA Contribution Limit: $3,300 (increased from $3,200 in 2024) Maximum Carryover, if plan permits: $660 (increased from $640 in 2024) Grace Period, if plan permits: Up to 2.5 months after plan year end, for example March 15 for calendar-year plans Dependent Care FSA Limit: $5,000 per household, or $2,500 if married filing separately

The Use-It-or-Lose-It Rule

Funds not used by the plan year deadline are forfeited back to the employer. Employers may offer one of two relief provisions, but not both simultaneously. Under the Carryover provision, up to $660 in unused funds may roll into the following plan year. Under the Grace Period provision, employees have up to 2.5 additional months after the plan year ends to incur and submit eligible expenses. If neither provision is offered, all unused funds are forfeited. Employees should estimate healthcare spending carefully and avoid over-contributing to an FSA.

Limited-Purpose FSAs

Employees enrolled in an HSA-eligible High Deductible Health Plan generally cannot also contribute to a general-purpose FSA. However, they may contribute to a limited-purpose FSA restricted to dental and vision expenses. This arrangement allows HSA contributors to use pre-tax dollars for predictable dental and vision costs while preserving the HSA for medical expenses and long-term growth.

Strategy: When an employer offers both an HSA-eligible HDHP and a limited-purpose FSA, maximizing both accounts is worth considering. In 2025, this means up to $4,300 in HSA contributions for self-only coverage plus up to $3,300 in limited-purpose FSA contributions, totaling $7,600 in pre-tax healthcare dollars that reduce both income and FICA taxes.

Health Savings Accounts (HSAs)

An HSA is a portable, individually owned account available exclusively to individuals enrolled in a qualifying High Deductible Health Plan. HSAs offer what financial planners describe as a triple tax advantage: contributions are tax-deductible or pre-tax via payroll (and also avoid FICA when made through payroll), investment earnings accumulate completely tax-free, and qualified withdrawals are entirely tax-free.

2025 HDHP Requirements for HSA Eligibility

Self-Only Coverage: Minimum annual deductible of $1,650; maximum out-of-pocket limit of $8,300. Family Coverage: Minimum annual deductible of $3,300; maximum out-of-pocket limit of $16,600.

2025 HSA Contribution Limits

Self-Only HDHP: Base contribution limit of $4,300; catch-up contribution of $1,000 for those age 55 or older; maximum total of $5,300. Family HDHP: Base contribution limit of $8,550; catch-up contribution of $1,000 per eligible spouse age 55 or older, with each eligible spouse required to maintain a separate HSA.

Contributions may be made through payroll deduction, which avoids FICA taxes in addition to income taxes, or directly to the HSA custodian, which provides an above-the-line deduction on Schedule 1 but does not reduce FICA taxes. The contribution deadline is April 15 of the following year, which allows individuals to make prior-year contributions after December 31.

Important: Enrollment in Medicare, even when an HDHP is still in place, disqualifies the individual from making further HSA contributions. Individuals who delay Medicare enrollment beyond age 65 may continue contributing to their HSA.

HSA Withdrawal Tax Treatment

Qualified medical expenses, at any age: Withdrawals are 100% tax-free, with no income tax and no penalty. Non-qualified expenses, under age 65: Withdrawals are subject to ordinary income tax plus a 20% penalty tax. Non-qualified expenses, age 65 or older: Withdrawals are subject to ordinary income tax only, with no penalty. In this respect, the HSA functions similarly to a traditional IRA for non-medical expenses after age 65.

Rollover, Investment, and Retirement Features

Unlike FSAs, HSA funds never expire. Unused balances roll over automatically each year and may be invested in mutual funds or index funds once the account balance meets the custodian’s investment threshold, typically between $500 and $1,000. Investment earnings accumulate entirely tax-free when the funds are ultimately used for qualified expenses.

The Shoebox Strategy: One highly effective long-term approach is to maximize HSA contributions each year, pay current medical expenses out of pocket rather than from the HSA, and invest the HSA balance in index funds. All receipts for out-of-pocket medical expenses should be retained. At any future point, including years or decades later, the account holder may reimburse themselves tax-free for all prior qualified expenses. There is no IRS-imposed deadline for claiming reimbursement, provided the expenses were incurred after the HSA was established and are properly documented.

After age 65, the HSA functions as a general-purpose retirement savings vehicle. Non-qualified withdrawals are subject to ordinary income tax but carry no penalty, and unlike traditional IRAs and 401(k)s, HSAs are not subject to Required Minimum Distributions.

FSA vs. HSA: Key Differences

Contribution limit: FSA $3,300 compared to HSA $4,300 for self-only coverage or $8,550 for family coverage. Rollover: FSA unused funds are limited to a $660 carryover or a 2.5-month grace period. HSA balances roll over 100% indefinitely. Portability: FSA balances are generally forfeited upon leaving an employer. HSA accounts are fully portable and permanently owned by the account holder. Investment options: FSA balances are held in cash only. HSA balances may be invested once a threshold is met. Required Minimum Distributions: Not applicable to FSAs. HSAs have no RMDs. Best use: FSAs are well-suited for predictable near-term medical expenses. HSAs are best used as long-term healthcare savings vehicles and components of a broader retirement strategy.

Part 4: The Kiddie Tax

The kiddie tax prevents high-income parents from reducing their overall tax liability by transferring income-producing investments to their children, who would otherwise be taxed at a substantially lower rate. Under these rules, a qualifying child’s net unearned income above a threshold amount is taxed at the parent’s marginal rate rather than the child’s rate.

The kiddie tax was originally enacted under the Tax Reform Act of 1986. Congress temporarily restructured the rules in 2018 to apply trust and estate tax rates, but reversed that change under the SECURE Act of 2019, reinstating the use of the parent’s marginal rate. The current framework remains in effect for 2025.

Who Is Subject to the Kiddie Tax?

The kiddie tax applies to a child who satisfies all of the following conditions: the child has net unearned income exceeding $2,700 for 2025; the child meets one of the applicable age conditions (under age 18, or age 18 with earned income not exceeding half of their own financial support, or a full-time student between ages 19 and 23 whose earned income did not exceed half of their own support); at least one parent was living at the end of the tax year; the child is required to file a federal tax return; and the child does not file a joint return.

The kiddie tax applies exclusively to unearned income, which includes interest, dividends, capital gains, rents, royalties, and similar investment income. It does not apply to wages, salaries, tips, or self-employment income earned by the child.

2025 Kiddie Tax Thresholds

Tier 1, Tax-Free: The first $1,350 of unearned income is covered by the child’s standard deduction and is not subject to tax. Tier 2, Child’s Rate: Unearned income between $1,350 and $2,700 is taxed at the child’s own marginal rate, often 10% or 12%. Tier 3, Parent’s Rate: Unearned income above $2,700 is taxed at the parent’s marginal rate, which may reach 37% at the federal level.

The child’s standard deduction is the greater of $1,350 or earned income plus $450, subject to a maximum of $15,000, which is the 2025 standard deduction for single filers. A child with part-time employment income can shelter a greater portion of investment income from tax due to the higher earned-income-based standard deduction.

Worked Example

A 20-year-old full-time college student who qualifies as a dependent has a custodial investment account that generates $4,000 in dividend income during 2025. The student has no earned income.

The first $1,350 is not taxed, as it is covered by the standard deduction. The next $1,350 (from $1,350 to $2,700) is taxed at the student’s 10% rate, resulting in $135 of tax. The remaining $1,300 (above $2,700) is taxed at the parent’s 22% marginal rate, resulting in $286 of tax. The total tax on $4,000 of dividend income is $421. Without the kiddie tax, the total tax would have been only $135.

Filing Requirements

Children subject to the kiddie tax must attach Form 8615 (Tax for Certain Children Who Have Unearned Income) to their individual Form 1040. An alternative is available under limited circumstances: if the child’s gross income consists only of interest, dividends, and capital gain distributions totaling less than $13,500 in 2025, parents may elect to include the child’s investment income on their own return using Form 8814. While this simplifies filing, it may increase the parents’ taxable income and affect other income-dependent calculations, such as eligibility for Affordable Care Act premium tax credits.

Net Investment Income Tax Interaction

Children subject to Form 8615 may also be subject to the 3.8% Net Investment Income Tax if their modified adjusted gross income exceeds the applicable thresholds. This represents an additional layer of federal tax that can apply even to children, further compounding the effective tax rate on significant custodial account earnings.

Kiddie Tax Planning Strategies

Investing in growth-oriented equities that do not pay dividends defers any taxable event until the child sells the shares, ideally after aging out of kiddie tax eligibility. Interest from municipal bonds is generally exempt from federal income tax and does not count toward the kiddie tax threshold. Contributions to 529 college savings plans allow earnings to accumulate free of the kiddie tax, provided distributions are ultimately used for qualified higher education expenses. When a child has earned income from employment, contributions of up to $7,000 in 2025 may be made to a Roth IRA on the child’s behalf. Earnings in a Roth IRA grow tax-free and are not subject to the kiddie tax. Timing the realization of capital gains in custodial accounts to coincide with years after the child ages out of kiddie tax eligibility can reduce the overall tax cost. The simplest strategy in many cases is to structure the portfolio to generate $2,700 or less in taxable investment income per year, keeping all unearned income within Tier 1 or Tier 2.

Part 5: The Alternative Minimum Tax (AMT)

The Alternative Minimum Tax is a parallel tax system that operates alongside the regular federal income tax. Its purpose is to ensure that high-income taxpayers who benefit from deductions, exclusions, and preference items still pay at least a minimum level of federal tax. Each year, taxpayers must compute their liability under both systems and remit whichever amount is higher.

The Tax Cuts and Jobs Act of 2017 significantly raised AMT exemption amounts and phase-out thresholds, substantially reducing the number of taxpayers affected. Nevertheless, the AMT has not been repealed and remains a meaningful consideration for taxpayers with large ISO exercises, substantial accelerated depreciation deductions, or significant state and local tax deductions.

How AMT Is Calculated: Six Steps

Step 1: Begin with regular taxable income. Step 2: Add back AMT adjustments (the PANIC TS items). Step 3: Add AMT tax preference items (the PPP items). Step 4: Subtract the applicable AMT exemption, which phases out at higher income levels. Step 5: Apply the AMT rate: 26% on the first $116,300 of AMTI above the exemption and 28% on AMTI above that amount for 2025. Step 6: Compare the resulting figure, known as the Tentative Minimum Tax (TMT), to regular tax liability. If TMT is greater, the taxpayer remits regular tax plus the excess of TMT over regular tax. That excess is the AMT.

AMT Adjustments: PANIC TS

P, Passive Activity Losses: Passive losses permitted under the regular tax may be limited or recalculated under the AMT system. A, Accelerated Depreciation: Depreciation computed using MACRS accelerated methods must be recalculated using the slower Alternative Depreciation System (ADS) straight-line method. The difference between the two depreciation figures is added back to AMTI. N, Net Operating Losses: The NOL deduction allowed under the regular tax must be recomputed as an AMT Net Operating Loss using AMT-adjusted figures. I, Installment Method: Dealers in personal property are not permitted to use the installment method for AMT reporting purposes. The full gain must be recognized in the year of sale. C, Long-Term Contracts: The completed-contract method of accounting, which may be used for certain construction and manufacturing contracts under the regular tax, is not permitted under the AMT. The percentage-of-completion method must be used instead. T, Taxes Deducted as Itemized Deductions: State and local taxes (SALT) deducted as itemized deductions under the regular tax are added back for AMT purposes. S, Standard Deduction: If the taxpayer elected the standard deduction under the regular tax system, that deduction must be added back for AMT purposes, as the AMT does not recognize the standard deduction.

AMT Tax Preference Items: PPP

P, Private Activity Bond Interest: Interest on certain private activity bonds that is exempt from regular income tax is included in AMTI. Interest on general obligation public-purpose bonds is not a preference item and does not require an adjustment. P, Percentage Depletion: The excess of the percentage depletion deduction over the adjusted basis of the property is a preference item applicable to oil, gas, and mineral extraction. This preference applies even after the property’s cost basis has been fully recovered. P, Pre-1987 Accelerated Depreciation: Accelerated depreciation claimed prior to 1987 on real property in excess of straight-line depreciation remains a preference item for taxpayers who continue to benefit from those older deductions.

2025 AMT Exemption Amounts and Phase-Outs

Single or Head of Household: Exemption of $88,100; phase-out begins at $626,350; exemption is fully phased out at $978,750. Married Filing Jointly: Exemption of $137,000; phase-out begins at $1,252,700; exemption is fully phased out at $1,800,700. Married Filing Separately: Exemption of $68,500; phase-out begins at $626,350; exemption is fully phased out at $900,350.

The exemption is reduced by $0.25 for every $1.00 of AMTI above the applicable phase-out threshold. Once AMTI reaches the upper limit, the exemption is eliminated entirely and the full AMTI is subject to AMT rates.

The ISO–AMT Connection

The most frequently encountered trigger for unexpected AMT liability in modern compensation structures is the exercise-and-hold strategy applied to ISOs. When an employee exercises ISOs and does not sell the shares before year-end, the bargain element is added to AMTI as a preference item, even though no regular income tax is owed. If this causes the Tentative Minimum Tax to exceed the employee’s regular tax, the employee owes the AMT difference in cash, potentially while holding illiquid private company shares that cannot be readily sold to fund the obligation.

Illustrative Scenario: An employee exercises ISOs representing $500,000 in spread in a year when regular taxable income is $200,000. The $500,000 AMT preference item increases AMTI above $700,000, producing a Tentative Minimum Tax of approximately $196,000. If the employee’s regular tax liability is only $50,000, the AMT due is $146,000, payable in cash while the employee holds stock that has not yet been sold or may not be liquid. This exact situation caused severe financial hardship for many technology employees during the dot-com collapse of 2000 and 2001, and it remains a live risk today.

The AMT Credit (Minimum Tax Credit)

When a taxpayer pays AMT in an ISO exercise year, the amount of AMT paid creates a Minimum Tax Credit, tracked on Form 8801. This credit carries forward indefinitely and may be applied against regular tax liability in future years when regular tax exceeds AMT. In most circumstances, AMT paid on ISO exercises represents a timing difference rather than a permanent increase in tax burden. The credit will ultimately be recovered in years during which the taxpayer is not subject to AMT.

AMT Planning Strategies

Before executing any ISO exercise, the taxpayer’s advisor should calculate the cushion between regular tax liability and the Tentative Minimum Tax. This calculation reveals the maximum amount of ISO spread that can be recognized without triggering AMT in the current year. Distributing ISO exercises across multiple years avoids concentrating a large AMT preference item in a single tax year. Exercising ISOs when the spread is small, such as during a market correction, a company down round, or immediately following a fresh 409A valuation, reduces the AMT preference item per share. In years when the employee has elevated ordinary income from bonuses or RSU vests, exercising ISOs may produce less AMT than expected because the higher regular tax liability narrows the gap between regular tax and TMT, potentially eliminating AMT entirely. Combining large ISO exercises with other significant capital gain events in the same year should be avoided without first modeling the combined AMT impact. Any prior AMT credit carryforward should be tracked annually on Form 8801 and applied against regular tax liability whenever the taxpayer is not subject to AMT.

Conclusion: Bringing It All Together

Modern compensation packages routinely include multiple forms of equity alongside tax-advantaged benefit accounts, and each component carries its own set of tax rules, planning opportunities, and risks that can significantly affect how much of one’s compensation is ultimately retained.

Tax timing is a critical variable. Whether exercising options, vesting RSUs, or withdrawing from an HSA, the timing of each transaction relative to income level, tax bracket, and applicable holding period requirements has a substantial effect on the taxes owed.

Default withholding rates frequently fall short. Supplemental wage withholding applied to RSU vests at 22% often fails to cover actual tax liability for employees in higher brackets. Quarterly estimated tax payments made in advance of anticipated income events can prevent underpayment penalties and year-end shortfalls.

Long-term capital gains treatment produces meaningful tax savings. ISO qualifying dispositions, post-vest RSU holds exceeding one year, and ESPP qualifying dispositions can convert income that would otherwise be taxed at ordinary income rates (up to 37%) into long-term capital gain taxed at 0%, 15%, or 20%. The cumulative tax savings over a career can be substantial.

The AMT represents a genuine and ongoing risk for ISO holders. Exercising and holding ISOs at companies with rising valuations can produce large and unanticipated AMT obligations. AMT exposure should be modeled carefully before any significant ISO exercise is executed.

Tax-advantaged accounts such as HSAs and FSAs provide low-risk, high-value tax savings. Maximizing contributions to both each year reduces income and FICA taxes. The HSA’s triple tax advantage, combined with indefinite rollover and investment capability and the absence of Required Minimum Distributions, makes it one of the most effective savings vehicles available under the federal tax code.

The kiddie tax constrains income-shifting strategies involving custodial accounts. Most unearned income above $2,700 generated in a qualifying child’s account is taxed at the parent’s marginal rate. Investment selection and account structure should reflect this limitation.

The strategies discussed throughout this guide can materially reduce tax liability and improve long-term financial outcomes. Because every taxpayer’s situation is unique and the interaction among different compensation types, filing status, state tax obligations, and other factors can be complex, working with a qualified CPA, tax attorney, or financial advisor with specialized knowledge of equity compensation is strongly recommended before making decisions related to option exercises, RSU planning, or significant healthcare account withdrawals.

Disclaimer: This blog post is for educational and informational purposes only and does not constitute tax, legal, or financial advice. Tax laws are subject to change and individual circumstances vary significantly. All figures reflect 2025 IRS guidelines as verified at the time of publication. Readers should consult a qualified CPA, tax attorney, or financial advisor before making any decisions related to the topics discussed in this article.