This document contains a final regulation under Title I of the Employee Retirement Income Security Act (ERISA) that establishes additional criteria under ERISA section 3(5) for determining when employers may join together in a group or association of employers that will be treated as the "employer" sponsor of a single multiple- employer "employee welfare benefit plan" and "group health plan," as those terms are defined in Title I of ERISA. By establishing a more flexible "commonality of interest" test for the employer members than the Department of Labor (DOL or Department) had adopted in sub- regulatory interpretive rulings under ERISA section 3(5), and otherwise removing undue restrictions on the establishment and maintenance of Association Health Plans (AHPs) under ERISA, the regulation facilitates the adoption and administration of AHPs and expands access to affordable health coverage, especially for employees of small employers and certain self-employed individuals. At the same time, the regulation continues to distinguish employment-based plans, the focal point of Title I of ERISA, from commercial insurance programs and other service provider arrangements. The final rule also sets out the criteria that would permit, solely for purposes of Title I of ERISA, certain working owners of an incorporated or unincorporated trade or business, including partners in a partnership, without any common law employees, to qualify as employers for purposes of participating in a bona fide group or association of employers sponsoring an AHP and also to be treated as employees with respect to a trade, business or partnership for purposes of being covered by the AHP. The regulation would affect AHPs, bona fide groups or associations of employers sponsoring such plans, participants and beneficiaries with health coverage under an AHP, health insurance issuers, and purchasers of health insurance not purchased through AHPs.