If you are enrolled in an ACA-compliant plan, you will have 6 months from the time you received notice that your claim was denied to file an internal appeal. The Explanation of Benefits form that you get from your plan must provide you with information on how to file an internal appeal and request an external review. If your plan is fully insured, you can get help filing an appeal from your state's Department of Insurance. Your state may have a program specifically to help with appeals. If you have a self-funded plan and have questions or need help, contact the Department of Labor. (HealthCare.Gov, Internal Appeals).