the Treasury and the Secretary of Labor (or such Secretaries' delegates) shall, in cooperation, modify the returns required under section 6058 of the Internal Revenue Code of 1986 and the reports required by section 104 of the Employee Retirement Income Security Act of 1974 ( 29 U.S.C. 1024 ) so that all members of a group of plans described in subsection (c) may file a single aggregated annual return or report satisfying the requirements of both such sections. (b) Administrative requirements In developing the consolidated return or report under subsection (a), the Secretary of the Treasury and the Secretary of Labor (or such Secretaries' delegates) may require such return or report to include any information regarding each plan in the group as such Secretaries (or delegates) determine is necessary or appropriate for the enforcement and administration of the Internal Revenue Code of 1986 and the Employee Retirement Income Security Act of 1974. (c) Plans described A group of plans is described in this subsection if all plans in the group— (1) are individual account plans or defined contribution plans (as defined in section 3(34) of the Employee Retirement Income Security Act of 1974 ( 29 U.S.C. 1002(34) ) or in section 414(i) of the Internal Revenue Code of 1986)