The U.S. Supreme Court case Duffy, Former Collector v. Mutual Benefit Life Insurance Company in 1926 revolved around the issue of taxation on life insurance policies issued by foreign corporations doing business within the United States. The plaintiff, a former tax collector named Duffy, argued that taxes should be levied on these policies under Section 219 of the Revenue Act of 1918 which imposed an excise tax on all premiums paid to foreign insurers for domestic risk coverage. However, Mutual Benefit Life Insurance Company contended that they were exempt from this taxation as their policyholders' contracts were made and executed outside U.S borders despite being enforced domestically. The Supreme Court ruled in favor of Mutual Benefit Life Insurance Company stating that while Congress had power to impose such a tax it did not express clear intent to do so with respect to insurance contracts made abroad but enforceable domestically within Section 219's language or context. Therefore, no taxes could be collected from these types of transactions unless explicitly stated by law.

In the dissenting opinion for Duffy v. Mutual Benefit Life Insurance Company, Justice Oliver Wendell Holmes Jr. argued that the majority's decision to allow a life insurance company to claim tax deductions on policyholder dividends was incorrect. He believed that these dividends were not true business expenses but rather a return of excess premiums to policyholders and thus should be considered taxable income under federal law. In his view, allowing such deductions would result in an unfair advantage for mutual benefit life insurance companies over other types of businesses which could not deduct similar payments made to their customers or shareholders from their taxable income.