Some do and some don't. You may have to check with your provider to be sure. Some won't but will cover orthodontia that can be used in treating tmj. Also check your medical insurance - my splints were covered under my insurance with UHG. If they do not cover treatment under tmj ask if they cover orthotic treatment for myofacial or orofacial pain syndrome or cranial dissorders - they are quite similar in symptoms and treatment and for some reason will cover one but noth the other - some medical insurance cos just tend to shy away from the term TMJ since it implies "dental" problem only.