This document contains final regulations under section 410(b) of the Internal Revenue Code. The final regulations permit, in certain circumstances, employees of a tax-exempt organization described in section 501(c)(3) to be excluded for the purpose of testing whether a section 401(k) plan (or a section 401(m) plan that is provided under the same general arrangement as the section 401(k) plan of the employer) meets the requirements for minimum coverage specified in section 410(b). These regulations affect tax-exempt employers described in section 501(c)(3), retirement plans sponsored by these employers, and participants in these plans.