The cost ranges from $3,000 to $6,000 depending on where you live, how complex your case is, and whether you are treated by a general dentist or an orthodontist. There are different "levels" of invisalign (Invisalign Full, Teen, Express 10, Express 5). Usually your dentist will decide which level under which you will fall. Additional charges may be incurred for replacing lost aligners (usually they will replace the first one for free), retainers, and refinements. A refinement is needed when the teeth are not tracking as expected or there is a need for mid-course correction. Depending on which level of invisalign you are in, the refinement may or may not be an additional charge.