Per te EBIA ERISA Compliance for Health & Welfare Plans guidebook, mega-wrap or umbrella plan documents combining a variety of welfare plans (permitting one 5500 filing in lieu of several) are supposed to be adopted prospectively only. Does this mean the plan must be in place as of the first day of the plan year for which combined reporting will occur, or is it still prospective if adoption occurs anytime during that year, and is retroactive to the first day of the plan year?