Ask a billing team why a claim got denied and the answer is usually specific: wrong code, missing documentation, authorization lapsed. Zoom out across a full denial pattern, and a different picture shows up, one where the root cause, the payer’s own incentives, and the exact code on the remittance all tell a piece of the same story.
- Most denials trace back to a small number of root causes repeating across claims, not a unique problem each time.
- Payers have a real incentive to deny first and ask questions later — a denial that gets appealed and overturned still bought the payer time on that dollar amount.
- The denial code itself is usually two codes, not one — a CARC stating the category and a RARC adding the specific reason, and most billing teams only read half of it.
- Fixing denials at the root cause level prevents far more than appealing them one at a time ever will.
Each view below answers a different question about the same denial. Behavioral health denial management that reads only one of them keeps solving individual claims instead of the pattern producing them.
Start with the pattern underneath individual denials. Root cause analysis covers why a handful of recurring issues, not a unique problem on every claim, usually explain most of a facility’s denial volume.
That’s good news operationally. A small number of root causes means a small number of fixes can prevent a large share of future denials, instead of appealing the same underlying problem claim by claim indefinitely. The arithmetic favours prevention for a second reason: budget 30 to 60 days for a first-level appeal decision, another 30 to 60 for second level, and 30 to 45 for external independent review, so a denial fought all the way through can outlast the quarter it belongs to.
Reviewing a pattern of denials to identify the small number of recurring, systemic issues behind them, rather than treating each denial as an isolated event requiring its own investigation.
Root causes don’t happen in a vacuum. How payers manufacture denials covers the incentive structure behind it: a payer that denies first and asks questions only if appealed keeps that dollar amount longer, whether or not the denial holds up.
This isn’t a conspiracy theory. KFF’s own research on claims denials documents how often initial denials get appealed and overturned, evidence that a meaningful share of first-pass denials weren’t well-founded to begin with. The cheapest denial is still the one that never gets filed, which puts catching routing errors before submission ahead of any appeal strategy.
Treating each denial as a one-off to appeal misses what the pattern is actually saying. The same root cause producing repeat denials, combined with a payer’s incentive to deny first, means every denial carries information about both the billing process and the payer’s own behavior. Reading only the appeal outcome throws that information away.
Reading that information requires reading the actual code. The CARC/RARC denial code taxonomy covers why a remittance advice carries two codes working together, not one, and why most billing teams miss half the signal by only reading the category code.
A CARC alone says a claim was adjusted for a general reason. The paired RARC says specifically why. Diagnosing a denial pattern accurately, and telling root cause from payer behavior, usually requires both codes read together, not just one.
Root cause, incentive structure, and code-level detail are three views of the same denial pattern. Treating denial management as a system that reads all three, instead of appealing claims one at a time, is what actually reduces future denial volume.
Does every denial have its own unique cause?
No. Most denial volume traces back to a small number of recurring root causes, which means fixing those causes prevents far more future denials than appealing each one individually.
Do payers actually benefit from denying claims that get overturned on appeal?
Yes, in terms of timing. A denial that gets appealed and later overturned still let the payer hold that dollar amount longer than if it had been approved on the first pass.
Is a CARC code enough to understand why a claim was denied?
Not on its own. A CARC states the general category of adjustment; the paired RARC adds the specific reason. Reading only the CARC misses half the actual explanation.
What's the most effective way to reduce denial volume long-term?
Addressing root causes across a pattern of denials, rather than appealing each denial individually, since a small number of systemic fixes typically prevents a large share of future denials.
- Root cause analysis across denial patterns, not one-off appeals
- CARC and RARC read together to diagnose denials accurately
