In my professional interpretation, every entitity involved in the administration of an employee benefit plan has a high degree of fiduciary responsibility.
Tier I responsibility lies with the Plan Administrator. This is the role of whoever whoever is the lead stakeholder in charge of human ressources management. This position has full and final authority & accountability. Every other entity typically exercise a degree of plausble deniability.
Tier II responsibility lies with the selected broker. The broker of record is responsible for balancing the fiduciary needs of the lead stakeholder and the capabilities of the needs of the competitively selected carrier.
Tier III responsibility lies with the selected benefit(s) carrier. For marketplace competitive reasons, they will promise the best but have no accountability, consequences or for operational or administrative failures.
The tiers of consequence, concession and/or accountability are certainly prickly. Reliance on processes untouched by human minds is the prickly path to fiduciary failure.
Open Enrollment Rule # 1: Do all things necessary to honor participant elections.
Open Enrollment Rule #2: See Rule #1.
There are no other Open Enrollment Rules.