Multiemployer defined benefit plans are required to provide a summary report to each union and employer contributing to the plan within 30 days of the due date of Form 5500, including extensions. This report must include certain information that multiemployer pension plans are also now required to report on Form 5500, such as employers contributing more than 5% of total contributions; information on amortization extensions and the plan's funded status; the number of participants with no contributing employer; the number of contributing employers; and the number of employers that withdrew during the plan year and related withdrawal liability.

For plan years ending December 31, 2010, the deadline for providing the summary plan information is August 30, 2011. However, if the filing deadline for a plan's Form 5500 is extended, the deadline to provide the summary plan information is also extended by two months.