For insurance to cover any part of a Tummy Tuck depends on your insurance company and your own policy.  You need to check with them, and get it in writing.

If you have an overhanging apron that causes medical problems, some insurance companies MAY allow for apronectomy (panniculectomy).  A panniculectomy is just an excision of the overhanging skin and fat.  It Does Not Allow For Repair of the Muscles and Does Not Allow For Repositioning Of The Belly Button.  THAT IS AN ABDOMINOPLASTY (TUMMY TUCK).

Therefore they may pay for the panniculectomy (anesthesia and hospital or facility cost), and YOU pay for the abdominoplasty portion, which includes the cosmetic result, the tightening of the muscles and repositioning of the belly button.  You need to check with your insurance company for exact details of what they will cover and what they do not.  Remember that some insurance may only pay for part of the cost of anesthesia and part of the hospital or facility. 

Your plastic surgeon may write a letter and send photographs to the insurance company for pre-authorization, but even with pre-authorization they may later deny payment.

Consult a board certified plastic surgeon for complete examination and recommendations, alternatives and risks involved.