Is a person who has discretionary responsibility in the administration of an ERISA plan a fiduciary?

Persons who perform purely administrative functions within a framework of policies, interpretations, rules, practices and procedures made by other persons are not fiduciaries. However, discretionary authority or discretionary responsibility in the administration of a plan will make a person a fiduciary. For example, a plan administrator and named fiduciary successfully pressed a fiduciary breach claim against an insurance company that managed a self-insured health plan. When an insurance company administers claims for a welfare plan and has authority to grant or deny the claims, the company is an ERISA "fiduciary." A party that undertakes to act as plan administrator will be treated as such even if that role is reserved for another entity.