If I get a nose job is it possible to pass it off as for a medical reason rather than cosmetic, and would doctors support this?

You are asking a surgeon to lie for you.  If a surgeon will lie to your insurance company, that would not be a surgeon I would trust. At 21, you are an adult and are free to make your own decisions and do not need parental consent to undergo plastic surgery, even though it would be nice to have their support.

Hello, Although performing a cosmetic rhinoplasty and billing insurance for medical reasons is fraud and a crime for a surgeon, I don't believe that's what you're asking. You need the support of your parents, both financially and emotionally.  You wouldn't be a good candidate then. Any result you get will be analyzed and potentially critiqued negatively by your parents, and you in turn will become unhappy with the result. You should wait until home circumstances change. 

The only parts of a rhinoplasty that insurance will cover are functional ones... Like breathing. Any doctor who lies about this is committing fraud and is risking losing their license.

At the age of consent, you can choose to have a rhinoplasty if you wish.  This is your decision, and even if your parents don't support it, you can still opt for it.  This sounds like a purely cosmetic procedure so you would need to pay out of pocket.  If you really wish to proceed, begin disiplined saving for it so you can cover the cost.  Asking a doctor to try and get a cosmetic procedure covered by insurance is insurance fraud and can result in the doctor losing his/her license.  Good luck

 It is important to have another conversation with  your parents to tell them how this significantly affects  your esteem and self confidence, so that they can reconsider their decision. A psychologist and/or psychiatrist may be able to help intervene between you and your parents. There is no medical necessity for taking off a dorsal hump, since it is considered cosmetic. Patients must pay for this portion of the surgery themselves.

A cosmetic rhinoplasty can be combined with a septoplasty to address functional concerns with breathing. However, there is no medical reason for removing the bump by itself. 

Thank you for your question and Dr Nazarian appears to have hit the nail right on the head but try to get your parents to go with you to see a surgeon and perhaps the surgeon can explain how important it is for your self esteemDr Corbin

In insurance billing, one must adhere to strict guidelines as to the medical problem and the surgery needed to correct it.  That said many, not all rhinoplasty patients have a functional problem with the airway being blocked to some degree. It has to be be documentted that there exists a functional airway problem with septum, turbinates, polyps or valve problems. In any event any portion of the surgery that is cosmetic is not billed to the insurance company but paid by  and listed on the insurance form as being already paid.The functional portion can be billed, if you have a predetermination from your insurance company as a separate procedure.If a total cosmetic procedure is done and billed as 100% functional surgery, both you and the surgeon can be charged with insurance fraud.

Most insurance policies will contribute to the cost of correcting functional nasal problems but will not cover the expense of cosmetic changes.