Insurance Coverage for Septoplasty

You are approaching it the wrong way.
Your first question should be, 'What do I want?' Better breathing, better looking nose, or both.
Septoplasty is easy and any ENT surgeon can do it for you. You should be able to find someone in your network.
Rhinoplasty is a whole different ball game. You want it done once and done right. Trying to save some money you might end up with a poor result. If money is an issue you should only get septoplasty and save money for a rhinoplasty down the road.
I see that you are new york. The best guy in my opinion to do a rhinoplasty in NY is Dr. Norman Pastorek.
Goodluck and regards

Many patients want both a functional correction of their nose as well as a cosmetic correction.  The functional portions of the case, such as septoplasty, are typically covered by insurance.  Each insurance plan is unique, so insurance plan benefits can be determined before the procedure to see what your anticipated coverage would be.  

A rhinoplasty is not covered by insurance and the cost is dependent on the surgeon's fee.

You need to contact your insurance carrier. They will give you the names of "in network" surgeons that will cover your surgery. If your nose was broken while you were under this same insurance, the cosmetic portion might be covered as it was caused by trauma, unless it has to be corrected within a certain time frame. If you have different insurance from when the injury happened, you need to find out if you have a "pre-existing" clause. Again, contact your insurance carrier as they will be able to give you referrals to help you find a surgeon, and tell you what your specific policy does and does not cover.

Health insurance should cover both Septoplasty and rhinoplasty in your case, as the deformity was caused by trauma.  Having said that, unfortunately many insurance companies try to get out of paying legitimate claims, and having a surgeon that would also be a good advocate on your behalf  with the insurance company would help.

Typically a skilled surgeon should be able to properly execute both rhinoplasty and Septoplasty at the same time.  Make sure you interview 2-3 surgeons, find out about their experience with your type of deformity and expected outcome both functionally and aesthetically.

A good rhinoplasty surgeon, whether they are an ENT or Plastic Surgeon, will be more than capable enough to do both a septoplasty and a cosmetic rhinoplasty.
However, insurance will only pay for the septoplasty portion of the operation.

Septoplasty is a surgery performed to correct a deviated (or crooked) septum. The septum is the piece of cartilage that separates one side of the nose from the other. Normally, the septum is straight. When it is crooked, it is termed a deviated septum. A deviated septum can block the nasal passage and contribute to symptoms of nasal obstruction.
A septoplasty does not change the shape of the nose and is therefore considered a functional procedure as opposed to a cosmetic procedure. As such, it is a procedure (as well as facility fees and anesthesia costs) that insurance should pay for. Verification of benefits and prior authorization before surgery should be obtained. For patients without insurance, the surgeon's fee for a septoplasty can range between $1000 and $2000.
A septoplasty is frequently performed at the same time as the rhinoplasty. Your best bet is choosing one surgeon to perform both procedures. Even though the rhinoplasty portion of your surgery will be considered cosmetic, the functional component will be covered by your insurance and may decrease your out of pocket expense.