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How to Appeal a Prior Authorization Not Obtained Denial

Service denied because prior authorization was not obtained. Appeal with retroactive authorization request or proof of emergency/urgency.

~65% typical appeal success rate
Codes CO-15

Why insurers issue Prior Authorization Not Obtained denials

Service denied because prior authorization was not obtained. Appeal with retroactive authorization request or proof of emergency/urgency. Recognizing the denial type is the first step — it determines which arguments and evidence will actually move the reviewer.

The appeal strategy that works

For Prior Authorization Not Obtained denials, the winning approach centers on retroactive auth: directly rebut the insurer's stated reason, then back it with the evidence reviewers respect.

The strongest supporting evidence for this denial type:

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CareCost Appeals classifies your denial, pulls the right evidence (real, verified clinical citations and the insurer's own policy where available), applies your state and federal appeal rights, and produces a ready-to-send letter — free.

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