If you become disabled but are too young to qualify for regular retirement, you may have the right to apply for disability retirement benefits. To be found eligible for disability retirement under the Federal Employees Retirement System (FERS), you must show that you have become so disabled that you can no longer render useful and efficient service in your position and that your disability is expected to last at least one year. The general rule in disability retirement cases is that your medical evidence must show how your condition affects your ability to perform specific job duties and requirements. See Tanious v. Office of Personnel Management, 34 M.S.P.R. 107, 111 (1987). Typically, your own subjective evidence of disability is not entitled to weight if it is not corroborated by competent medical evidence.