Four types of health insurance plans that are differentiated based on the average percentage of health-care expenses that will be paid by the plan. Under the Patient Protection and Affordable Care Act (ACA), the U.S. health reform enacted March 23, 2010, health insurance plans are offered in four actuarial levels: Bronze, Silver, Gold and Platinum. The level defines the amount of expenses each type of plan covers. The higher the actuarial value (i.e. Gold and Platinum), the more the plan will pay, on average, toward health-care expenses; the lower the actuarial value (Bronze and Silver), the less the plan will pay.