What are my chances of approval for breast reduction?

You will find that coverage of the procedure varies widely from one insurance policy to the next. Many insurance companies will cover if you have 500 grams of excess breast tissue (about 1 lb) per side and rarely some may cover as low as 350 grams. However some companies may require a kilo or more depending on your height and weight.  
.  You will have the least problems if you are in good health and a nonsmoker.  I don't perform breast reduction until a patient has quit smoking for 6 weeks before surgery because smoking greatly increases the odds of complications with surgery.  I also require that patients get their BMI down to 35 and have their diabetes under good control because we have done studies that show this decreases the risk of complications with surgery or anesthesia.  
This being said, before you go forward with surgical procedures you may want to see your primary care physician to see if they have any other recommendations and such as therapy or medications. Many neck and back pain symptoms can be treated very successfully with strengthening of the spinal supporting musculature and this may be required by your insurance company.  This requires some time and effort but may provide a lifetime of benefit.  
Insurance companies frequently want to see a record of having been treated by nonsurgical methods for at least six months and not getting improvement with conservative treatments.  This usually means that you have tried diet and exercise, medications and possibly therapy or chiropractic and have not gotten adequate relief.  The next thing to do is get an exam with a board certified plastic surgeon with a good reputation. He should be able to perform an exam to tell exactly how much excess breast tissue you have.  Then the surgeon will write a letter to the insurance company and see if they will give approval for the surgery. The insurance company will send both you and your provider a letter with their decision within a few weeks in most cases.  Many patients are able to get insurance coverage for the procedure, but if you do not qualify many places offer a significant reduction in the price for out of pocket cases that are paid in advance.  Best of luck on your journey

At
5’4 and 270 lbs, your BMI is 46, which puts you at a high risk for surgery complications.  An alternative to consider is liposuction of
the breasts.  Your insurance company may
or may not authorize this procedure.Best Wishes,Gary Horndeski, M.D.