Before the implementation of the CTB regulations, the United States characterized foreign entities for tax purposes based on a resemblance test that considered the concurrence of four corporate features, including: limited liability; continuity of life; centralized management, and free transferability of interests (known as “Kintner test”).

—holding that an "association" under state law could also be treated as a corporation for purposes of the Code because the Code may be more expansive than categories enumerated under state law

These regulations, however, were only useful to the extent that an association or similar entity was not incorporated under state laws but was still taxed as a corporation.

その後, S 法人選択よりも LLC など他のパススルー課税が認められる法形式の事業体の選択が広がるなか, パススルー課税の選択が租税回避につながることがないようにとのことで, 連邦財務省は, 1960 年にキントナー規則 (Kintner Regulations

—the Ninth Circuit affirmed the trial court's finding that a group of doctors who were operating a clinic under "articles of association" should be taxed as a corporation under the

—the federal district court and the Ninth Circuit determined that an association of medical professionals that had more corporate than non-corporate characteristics was taxable as a corporation for federal tax purposes.

—state law partnership imbued with sufficient corporate characteristics to adopt corporate qualified retirement plan

Prior to 1962, however, a partner who performed services for his partnership was not considered an employee for the purposes of those provisions, with the results that the partnership was not entitled to a deduction and the partner was currently taxable on his proportionate share of contributions made for his benefit to the partnership's profit-sharing plan.

—several doctors who had practiced medicine as a partnership dissolved the partnership and established an unincorporated association.

"Michigan cannot, by its decisions and laws governing questions over which it has final say, also decide issues of federal tax law and thus hamper the effective enforcement of a valid federal tax levied against earned income