An "HSA" or "health savings account" is an account, funded by an individual or his or her employer, designed to help pay for an individual's medical expenses below the individual's health insurance deductible. Eligibility for an HSA is restricted to individuals who belong to a high deductible health plan and who are not enrolled in Medicare or listed as dependents on another person's tax returns. There is a maximum yearly contribution to an HSA, and funds deposited are tax deductible, and they are placed in certain investments, which grow tax free. Withdrawals from the account made for the purpose of qualified medical expenses are not taxed.