Famous Tax Court Cases That Shaped U.S. Tax Law

The tax rules Americans live under were shaped less by statute alone than by a series of court fights over specific dollar amounts on specific returns. The famous tax court cases that shaped US tax law defined what counts as income, who owes tax on it, which expenses are deductible, when a clever transaction is really a sham, how illegal money is treated, and how gifts and estates are valued. Most reached the Supreme Court. All of them still ripple through every filing season.

What Counts as Taxable Income

The Internal Revenue Code defines gross income as broadly as possible: all income from whatever source derived.¹ Three cases show how far that language reaches.

Glenshaw Glass and the Modern Definition of Income

Glenshaw Glass received punitive damages in a fraud and antitrust settlement and left the money off its tax return, arguing that punitive damages weren’t the kind of “income” Congress meant to tax. The Supreme Court disagreed in 1955 and produced a three-part test that still governs. Taxable income is any gain that represents a clear increase in wealth, that the taxpayer has actually received, and that the taxpayer controls freely. Punitive damages checked every box. So do prize money, gambling winnings, and virtually every other financial benefit that lands in your hands, unless the Code contains a specific exclusion.

Kirby Lumber and Cancelled Debt

In 1931, Kirby Lumber issued bonds at face value, then repurchased some of them on the open market for less than it had received. The Supreme Court held that the difference was taxable income because the company freed up assets that had previously been tied to the debt obligation.² The principle, known as discharge-of-indebtedness income, reaches anyone who settles a debt for less than the balance owed. If a credit card company forgives $5,000 of your balance, that $5,000 is generally taxable in the year of forgiveness.

Cesarini and Found Property

A couple in Ohio bought a used piano and years later discovered $4,467 in cash hidden inside. A federal court ruled the money was taxable in the year they found it, applying the Treasury regulation that treats treasure trove as gross income in the year the finder takes undisputed possession.³ Found property of any kind, whether cash in a piano or a valuable painting at a yard sale, must be reported as income when discovered.

Who Owes Tax on Income

Taxpayers have long tried to shift income to family members in lower brackets. The Supreme Court shut that door early, and the rule it laid down still blocks most income-splitting arrangements.

Lucas v. Earl and the Fruit-and-Tree Rule

Guy Earl, a California attorney, had an agreement with his wife that they would split all their earnings equally. He reported only half his salary. The Supreme Court ruled in 1930 that income is taxed to the person who earns it, regardless of any arrangement to redirect it. Justice Holmes wrote that the tax could not be escaped by “anticipatory arrangements and contracts however skilfully devised” to keep the salary from vesting in the person who earned it.⁴ The metaphor stuck: you can’t attribute the fruit to a different tree from the one on which it grew.

Helvering v. Horst and Investment Income

Ten years later, the Court extended the rule to investment income. Horst owned negotiable bonds and, before the interest coupons came due, detached them and gave them to his son. The son collected the interest. The Supreme Court held that the power to dispose of income is the equivalent of owning it.⁵ By directing the interest to someone else, Horst enjoyed the economic benefit and owed the tax. The same logic applies if you earn a consulting fee and tell the client to pay your daughter instead. You still owe the tax.

Business Expenses vs. Personal Spending

The Code allows a deduction for ordinary and necessary business expenses,⁶ but flatly prohibits deductions for personal spending.⁷ Two cases mark the boundaries.

Pevsner and Work Clothes

A boutique manager was required to wear expensive Yves Saint Laurent clothing on the job to project the store’s image. She said she never wore the clothes outside of work and deducted their cost. The Fifth Circuit denied the deduction, applying an objective test: clothing is deductible only if it is required for the job, is not suitable for everyday wear, and is not actually worn as everyday clothing.⁸ Designer clothing is perfectly wearable off the clock, so the taxpayer’s personal choice not to wear it didn’t matter. Scrubs, hard hats, and theatrical costumes pass this test. A nice blazer does not.

Flowers and Your Tax Home

Travel expenses are deductible only when you travel away from your “tax home” on business. Your tax home is generally the area where your principal place of business is located, not necessarily where your house sits. The Supreme Court in Commissioner v. Flowers established a three-part test: travel expenses must be ordinary and necessary, incurred in pursuit of business, and incurred while away from the taxpayer’s tax home. If you choose to live two hours from the office, your daily commute isn’t deductible travel, no matter how expensive.

Sham Transactions and Economic Substance

Some of the most consequential cases involve the IRS looking past the paperwork to ask whether a transaction had any real purpose beyond dodging taxes. Two Supreme Court decisions built the framework, and Congress eventually wrote their logic into the Code.

Gregory v. Helvering and Business Purpose

In 1935, the Court considered a corporate reorganization that satisfied every statutory requirement but had no business purpose beyond reducing taxes. The taxpayer created a new corporation, transferred appreciated stock into it, dissolved the new corporation, and distributed the stock to herself, all to turn what should have been dividend income into a lower-taxed capital gain. The Court disregarded the entire transaction, holding that a reorganization must be more than “a disguise for concealing its real character.”⁹ Following the letter of the law wasn’t enough. The transaction had to be “the thing which the statute intended.”

Knetsch and Manufactured Interest Deductions

In Knetsch v. United States, a taxpayer borrowed millions from an insurance company to buy annuity savings bonds from the same company, then deducted the interest payments. Each year he borrowed slightly more than the previous year’s interest, generating enormous deductions while pocketing only a tiny net increase in cash value. The Supreme Court found the arrangement had “no commercial economic substance” and existed only to manufacture deductions.¹⁰ The interest deductions were disallowed because the underlying debt was a sham.

The Doctrine in the Code Today

These judicial principles are now written into the tax code. A transaction has economic substance only if it meaningfully changes the taxpayer’s economic position apart from tax effects, and the taxpayer has a real business purpose for entering into it.¹¹ Failing that two-part test triggers a 20% accuracy-related penalty on any resulting underpayment, or 40% if the taxpayer didn’t disclose the transaction.¹²

Illegal Income and Criminal Evasion

The IRS doesn’t care whether income is legal. What matters is whether the taxpayer received it and controlled it. This area also draws the line between failing to pay and actively cheating.

James v. United States and Embezzled Funds

A union official embezzled money and argued it wasn’t taxable because he owed an obligation to return it. The Supreme Court rejected that in 1961, ruling that embezzled funds are taxable in the year the embezzler takes control of them.¹³ The key was dominion and control: he spent the money as his own with no consensual repayment arrangement. The same rule reaches theft, fraud proceeds, and bribes. Repayment later produces a deduction in the year of repayment, but the income must still be reported when received.

Spies v. United States and What Makes Evasion a Felony

Simply failing to file or pay is a misdemeanor. Felony tax evasion requires an affirmative act designed to mislead the IRS. In Spies v. United States, the Supreme Court listed examples of conduct that elevates the offense to a felony, including keeping a double set of books, creating false invoices, destroying records, hiding assets, and concealing sources of income.¹⁴ Felony evasion carries up to five years in prison and fines up to $100,000 for individuals or $500,000 for corporations.¹⁵

Tellier and Criminal Defense Fees

Legal fees paid to defend against criminal charges connected to your business are deductible. In Commissioner v. Tellier, a securities dealer was convicted of fraud related to his business. The IRS conceded that the fees met the statutory test for business expenses but disallowed them on public policy grounds. The Supreme Court reversed, holding that the income tax is a tax on net income, not a penalty for wrongdoing.¹⁶ The deduction applies regardless of whether the defense succeeds.

Gifts, Trusts, and Estate Valuation

The Code excludes gifts from the recipient’s gross income,¹⁷ but disputes over what qualifies as a gift and how to value transferred property have produced some of the most important decisions in tax law.

Duberstein and the Meaning of a Gift

Duberstein ran a business and provided valuable customer referrals to an associate. The associate sent him a Cadillac as a thank-you and deducted it as a business expense. Duberstein called it a gift. The Supreme Court held that a tax-free gift must come from “detached and disinterested generosity” or from feelings like affection, respect, or charity.¹⁸ The critical question is the transferor’s real reason. If the transfer is motivated by a sense of obligation or an expectation of future business benefit, it’s compensation. The Cadillac was compensation. Employer “gifts” to employees, tips, and holiday payments from clients tend to fall on the taxable side of this line.

Crummey and Gifts Into Trust

The annual gift tax exclusion, $19,000 per recipient for 2026, only applies to gifts of a “present interest,” meaning the recipient must have an immediate right to use or enjoy the property.¹⁹ Most gifts made into a trust are considered future interests. The Ninth Circuit’s decision in Crummey v. Commissioner created a workaround estate planners use constantly: giving each beneficiary a temporary right to withdraw their share of a gift shortly after it’s made. As long as the withdrawal right is legally enforceable and the beneficiary is notified, the gift qualifies for the annual exclusion, even if everyone understands the beneficiary won’t withdraw the money. These “Crummey powers” appear in most irrevocable life insurance trusts.

Connelly and Life-Insurance-Funded Buybacks

The most recent landmark came in 2024. Two brothers owned all the shares of a building supply company, with an agreement that the corporation would buy back a deceased brother’s shares. The company held $3.5 million in life insurance on each brother to fund the buyout. When one brother died, the estate valued his shares at $3 million, arguing the insurance proceeds were offset by the company’s obligation to use them for the redemption. The IRS assessed the company’s total value at $6.86 million and calculated the deceased brother’s shares at $5.3 million.

The Supreme Court sided with the IRS, holding that the corporation’s obligation to redeem the shares did not reduce their value.²⁰ Life insurance proceeds are a corporate asset a willing buyer would factor into the company’s worth, and the redemption obligation doesn’t offset that value because the transaction is circular. The company pays the estate with its own assets, reducing its value by the same amount. Corporate-owned life insurance intended to fund a stock buyback now increases the taxable estate, the opposite of what many plans were designed to accomplish. Business owners with buy-sell agreements funded this way should revisit them.

Penalties and How Long the IRS Has

The cases above set what the law requires. Getting it wrong carries consequences that range from a percentage penalty to prison, and the IRS has more time than most people realize.

When an underpayment results from carelessness or disregard of IRS rules, the standard penalty is 20% of the underpaid amount.¹² The IRS normally has three years from the date a return is filed to assess additional tax. But if the return is fraudulent or part of a deliberate attempt to evade taxes, there is no time limit at all. The IRS can audit a fraudulent return decades later and assess the full amount owed plus penalties.²¹

1
Office of the Law Revision Counsel. 26 USC 61 Gross Income Defined
2
Justia U.S. Supreme Court Center. United States v. Kirby Lumber Co., 284 U.S. 1 (1931)
3
Justia Law. Cesarini v. United States, 296 F. Supp. 3 (N.D. Ohio 1969)
4
Justia U.S. Supreme Court Center. Lucas v. Earl, 281 U.S. 111 (1930)
5
Justia U.S. Supreme Court Center. Helvering v. Horst, 311 U.S. 112 (1940)
6
Office of the Law Revision Counsel. 26 USC 162 Trade or Business Expenses
7
Office of the Law Revision Counsel. 26 U.S. Code 262 – Personal, Living, and Family Expenses
8
Justia. Pevsner v. Commissioner, 628 F.2d 467 (5th Cir. 1980)
9
Justia U.S. Supreme Court Center. Gregory v. Helvering, 293 U.S. 465 (1935)
10
Justia U.S. Supreme Court Center. Knetsch v. United States, 364 U.S. 361 (1960)
11
Office of the Law Revision Counsel. 26 U.S. Code 7701 – Definitions – Section: Clarification of Economic Substance Doctrine
12
Office of the Law Revision Counsel. 26 U.S. Code 6662 – Imposition of Accuracy-Related Penalty on Underpayments
13
Justia U.S. Supreme Court Center. James v. United States, 366 U.S. 213 (1961)
14
Justia U.S. Supreme Court Center. Spies v. United States, 317 U.S. 492 (1943)
15
Office of the Law Revision Counsel. 26 USC 7201 Attempt to Evade or Defeat Tax
16
Justia U.S. Supreme Court Center. Commissioner v. Tellier, 383 U.S. 687 (1966)
17
Office of the Law Revision Counsel. 26 U.S. Code 102 – Gifts and Inheritances
18
Justia U.S. Supreme Court Center. Commissioner v. Duberstein, 363 U.S. 278 (1960)
19
IRS. IRS Releases Tax Inflation Adjustments for Tax Year 2026
20
Justia U.S. Supreme Court Center. Connelly v. United States, 602 U.S. (2024)
21
IRS. Overview of Statute of Limitations on the Assessment of Tax