above social security levels. These tier II taxes are based on the ratio of certain asset balances to the sum of benefit payments and administrative expenses. Revenues in excess of benefit payments are invested to provide additional trust fund income. The National Railroad Retirement Investment Trust manages and invests railroad retirement assets. Railroad retirement funds are invested in non-governmental assets, as well as in governmental securities. Additional trust fund income is derived from the financial interchange with the social security trust funds, revenues from federal income taxes on railroad retirement benefits, and appropriations from general treasury revenues provided after 1974 as part of a phase-out of certain vested dual benefits. Railroad Unemployment Insurance Act Under the Railroad Unemployment Insurance Act, unemployment insurance benefits are paid to railroad workers who are unemployed but ready, willing, and able to work and sickness benefits to railroad workers who are unable to work because of illness or injury. The RRB also operates a placement service to assist unemployed railroaders in securing employment. Benefit Year A new unemployment-sickness benefit year begins every July 1, with eligibility generally based on railroad service and earnings in the preceding calendar year. Up to 26 weeks of normal unemployment or sickness benefits are payable to an individual in a benefit year. Additional extended benefits are payable to persons with 10 or more years of service. Financing The railroad unemployment-sickness benefit program is financed by taxes on railroad employers under an experience-rating system. Each employer's payroll tax rate is determined annually by the RRB on the basis of benefit payments to the railroad's employees. Organization and functions The Railroad Retirement Board is headed by three members appointed by the President of the United States, with the advice and consent of the Senate. One member is appointed upon the recommendation of railroad employers, one is appointed upon the recommendation of railroad labor organizations and the third, who is the chairman, is appointed to represent the public interest. The Board Members' terms of office are five years and are scheduled to expire in different years. The President also appoints an Inspector General for the RRB. The primary function of the RRB is the determination and payment of benefits under the retirement-survivor and unemployment-sickness programs. To this end, the RRB employs field representatives to assist railroad personnel and their families in filing claims for benefits, examiners to adjudicate the claims, and information technology