@savvyme1
Not sure how old you are but Medicare covers surgery to remove skin cancers.

You can always challenge why your insurance company did not pay. If they approved the surgery they know there are costs fo close the incsion.

Now if insurance refuses try to contact the insurance department of your medical provider. Many times they will reduce the costs and or set up payment plan.

Does your insurance company had what the call assignments or approved charged for medical treatments. Even is don't cover something usually have a approved costs medical provider can charge. Also did your medical provider accept assignments from your insurance company. If so they should have provided you the insurance costs.

If me would first file appeal with insurance company to cover the charge as for any surgery there will be incision closing costs. Second did the insurance company advise the medical facility prior to surgery they would not cover incision closing? If you were not told would not be covered prior by your insurance company you have a good appeal.

If all fails contact the medical provider's insurance deparment and advise your insurance did cover the procedure and you were told it did to then find out after surgery done that insurance did not cover the inscision closing.
Good Luck