Our insurance allows changes only during the enrollment period unless certain life events occur - death, marraige, childbirth, adoption, etc. Dental and Vision require a two-year committment while health, life, etc. is one year. This is done for the same reasons Randy is mentioning. Remember, group health generally does not have lengthy preexisting condition clauses and often is the only option available for individuals with a history of serious illnesses. Without the enrollment periods, the cost of insurance would be higher.