Governmental plans are exempt from PBGC coverage under the ERISA. Opinion letter 96-3 gives guidelines from the ERISA section (4021)(b)(2) for determining if an organization is a government employer.
Does a non-governmental 457(b) plan require a plan document?
Yes. A non-governmental 457(b) does require a written plan document. Unfortunately, there are no IRS pre-approved plan documents for non-governmental 457(b) plans. Nova 401(k) Associates provides plan documents.