This interim final rule describes revisions to the Form 5500 Annual Return/Report of Employee Benefit Plan and Form 5500-SF Annual Return/Report of Small Employee Benefit Plan (together "Form 5500 Annual Return/Report") to implement annual reporting changes for multiple-employer plans required by The Cooperative and Small Employer Charity Pension Flexibility Act (CSEC Act), enacted on April 7, 2014. The Form 5500 annual return/report is filed by employee benefit plans under the Employee Retirement Income Security Act of 1974 (ERISA) and sections 6047(e), 6057(b), 6058(a), and 6059 of the Internal Revenue Code (Code). The CSEC Act established additional annual reporting requirements for multiple-employer plans for plan years beginning after December 31, 2013, by adding new section 103(g) to Title I of ERISA. Specifically, the annual return/report of a multiple-employer plan must include a list of participating employers and a good faith estimate of the percentage of total contributions made by each participating employer during the plan year. This interim final rule also includes findings by the Department of Labor (Department) under the Administrative Procedure Act that good cause exists to adopt these revisions on an interim final basis without prior notice and public comments.