Amends Rule XXI (Restrictions on Certain Bills) of the Rules of the House of Representatives to make it out of order to consider any bill, joint resolution, amendment, amendment between the chambers, or conference report that would: result in a reduction of guaranteed Old Age, Survivors and Disability Insurance benefits; increase either the early or full retirement age for such benefits; privatize Social Security; result in a reduction of guaranteed benefits for individuals entitled to, or enrolled for, Medicare benefits; or result in a reduction of benefits or eligibility for individuals enrolled in, or eligible to receive medical assistance through, a state Medicaid plan or waiver under Grants to States for Medical Assistance Programs. Allows a waiver or suspension of this rule only by an affirmative vote of two-thirds of the Members.