Premiums are part of the cost of insurance not the entire cost. Sometimes there are co-pays that can be large. I know that the ACA comes in bronze/silver/gold varieties and I seem to remember reading somewhere that the premiums were the same and what was covered was the same among all the "metal" categories but the deductable/co-pay amounts were different. If you had bronze you had a bigger deductable or co-pay then silver or gold.