I have my own billing company. My appeal rate is probably around 95-97%. U&C reductions are my favorite as I will generate as many appeals necessary to get them to pay the full fee or close to it. I've also used ERISA law with group health plans and won appeals where the carrier tried to recoup overpayments from my clients when they should (by ERISA law) go after the patient for the payment. I worked for carriers for years never knowing what ERISA was because the carriers didn't want us to know because back then (and now) most billers and providers don't know or understand ERISA.
Case in point,on Thursday of last week we received a request for $3300 on claims from January to July of 2018 for a patient of one of my pediatric clients. it was UHC, the plan was group policy covered under ERISA, I sent letter back to them citing ERISA law and referred them to the patient. Their reasoning of the patient having other coverage (primary) was of no concern to us. So here you have what you may not consider an "appeal" but it was an adverse benefit determination but it was retroactive.
We had another OON surgical claim reduced from $4200 to $2600, I worked up U&C appeal, submitted operative report and we received check for another $500. I appealed again this time with a letter from the doctor, they sent us another $840 for total of $3940.. not bad
Believe me I completely understand your position. When I worked as a claims examiner I wouldn't know how to file an appeal the right way either, my mind was set, my job was to keep the insurance companies money for as long as I could. In fact I can still hear the ringing in my ears the essential phrase drilled into our brains "IF in doubt, knock it out". Translates to deny the claim let them appeal.
By all accounts you said it: "If nothing is denying, an appeal cannot be filed". keyword being "nothing". A claim reduction in benefits is a denial (adverse benefit determination) since "something" isn't paying.
