A Practice Note addressing how the Employee Retirement Income Security Act of 1974 (ERISA) completely preempts certain state claims that would otherwise duplicate, supplement, or supplant ERISA's civil enforcement provisions. A lawsuit may be completely preempted by ERISA (and be subject to removal) if it asserts a state-law cause of action to enforce the terms of an ERISA plan and that lawsuit conflicts with (or is duplicative of) the federal causes of action available under ERISA's civil enforcement provision.