((a)) ** Authority, time, and criteria** Within one year after , a multiemployer plan may irrevocably elect, pursuant to procedures established by the corporation, that the plan shall not be treated as a multiemployer plan for any purpose under this chapter or the Internal Revenue Code of 1954, if for each of the last 3 plan years ending prior to the effective date of the Multiemployer Pension Plan Amendments Act of 1980—
((1)) the plan was not a multiemployer plan because the plan was not a plan described in and (as such provisions were in effect on the day before ); and
((2)) the plan had been identified as a plan that was not a multiemployer plan in substantially all its filings with the corporation, the Secretary of Labor and the Secretary of the Treasury.
((b)) ** Requirements** An election described in subsection (a) shall be effective only if—
((1)) the plan is amended to provide that it shall not be treated as a multiemployer plan for all purposes under this chapter and the Internal Revenue Code of 1954, and
((2)) written notice of the amendment is provided to the corporation within 60 days after the amendment is adopted.
((c)) ** Effective date** An election described in subsection (a) shall be treated as being effective as of .September 26, 19801980-09-26