What is a ADA Code: An ADA code is normally a four digit number that identifies the exact dental service render. These ADA codes are the same for both the dentist and the insurance company. When shopping for dental insurance it is helpful if you already know your ADA codes for the dental services you are looking for. Say you know you need to have a filling, crown, root canal, etc, and you are trying to shop out insurance in order to make your needed dental care more affordable. Since there are many different ADA codes for fillings, crowns and root canals knowing which one you need will let you match up what you need when reviewing different dental insurance plan options. There by letting you pick a plan that can best fit your needs at the lowest cost to you.