Disability is by definition the worker's inability to work and earn income. Disability benefits guarantee workers some income security during periods in which they may not be able to work owing to poor health or other causes. Accordingly, disability is one of the most important benefits an employer can offer to an employee because it provides income in those circumstances when workers' compensation is either unavailable or insufficient. Short-term disability coverage is required by law in several states; therefore, employers should check their states' requirements. Disability benefits are subject to requirements of the Employee Retirement Income Security Act, including the requirement that a summary plan description be furnished to employees.