It lives in the insurer's system
The rules are applied when a claim arrives, which is weeks after the moment when producing the missing document would have taken thirty seconds.
Each insurer has a list. Which procedures need pre-authorisation, which need a referral, which codes pair with which treatments. That list is not secret and not disputed.
The rules are applied when a claim arrives, which is weeks after the moment when producing the missing document would have taken thirty seconds.
A referral letter that was easy to obtain during the admission is very hard to obtain six weeks after discharge.
Correction and resubmission restarts the queue, and a claim can go around three times over a document nobody disputes.
Staff were paid, supplies consumed, and the receivable sits. That cost reaches patients eventually.
The useful thing is your actual rejection reasons and how long a round trip takes.