Affordable Care Act premiums are going up next year. But you can find a cheaper one if you shop around. Premiums for the most popular plans under the affordable care act are slated to rise an average of about 5.2 percent. But many more insurers are offering plans for 2015. That means there is a wider selection, and likely more cheaper offers to choose from. You have until December 15 to decide, otherwise you will be automatically re-enrolled in your old plan.