"Prior to this change, it was relatively easy to correct errors in plan amendments -- as the IRS allowed sponsors to retroactively fine-tune their amendment language, and even adopt new retroactive amendments in certain cases, during the determination letter review process. This flexibility is now gone under the new system, and it will be more important than ever to adopt carefully drafted legally-required amendments on time. Otherwise, [EPCRS] will be the only alternative for fixing plan document errors retroactively."