Pension Accountability Act This bill amends the Employee Retirement Income Security Act of 1974 (ERISA) and the Internal Revenue Code to revise rules for voting on the suspension of pension benefits under multiemployer plans in endangered or critical status. The bill changes the voting procedure for suspending plan benefits to provide that a suspension shall go into effect unless a majority of plan participants and beneficiaries who cast a vote (currently, a majority of all plan participants and beneficiaries) reject the suspension. The bill also eliminates the authority of the Department of the Treasury, in the case of systemically important plans, to override a vote of plan participants to reject a suspension. A plan is systemically important if projected financial assistance to the plan will exceed $1 billion if suspensions are not implemented.