No, they don't stay buried forever in a cemetery. There is usually a contract between the family of the deceased and the cemetery. Some cemeteries have perpetual care contracts, which means that they agree to maintain the property in perpetuity and that your loved one's gravesite will never be reused. Other cemeteries typically have contracts that last around 25 to 50 years. After that time, the family of the deceased will need to make arrangements to have the body either moved or cremated.