In two cases, agents with the Internal Revenue Service (IRS) were investigating taxpayers for possible violations of income-tax laws. The taxpayers (defendants) gave tax documents prepared by their accountants to their respective defense attorneys, C.D. Kasmir and Solomon Fisher. The attorneys were served summonses ordering them to produce those documents. Kasmir and Fisher opposed producing the documents based on their clients' privilege against self-incrimination under the Fifth Amendment and the attorney-client privilege. The district courts enforced the summonses, and the attorneys appealed. The United States Court of Appeals for the Third Circuit affirmed the enforcement of the summons in Fisher's case, but the United States Court of Appeals for the Fifth Circuit reversed in Kasmir's case. The United States Supreme Court granted certiorari.