What is the difference between a rejection and a denial?

A rejection never entered adjudication — the clearinghouse or payer bounced it for a format or eligibility error, and you can correct and resubmit it. A denial was adjudicated and refused, so it needs a corrected claim or a formal appeal within the payer's deadline.

How long do I have to appeal a denied claim?

Commercial payers commonly allow 90 to 180 days from the remittance date, Medicare allows 120 days for a redetermination, and some plans allow as little as 60. The remittance advice states the window; calendar it the day the denial posts.

Which denials should I work first?

Sort by recoverable dollars and by deadline, not by age. High-value denials with a clear fix and a closing appeal window come first; low-dollar denials with systemic causes belong in a process fix, not in the appeal queue.

What denial rate is acceptable?

Under 5% on first-pass submissions is a realistic target for most specialties. Anything above 10% usually points at front-end eligibility and authorization failures rather than coding.

Do appeal letters actually work?

Yes, when they cite the specific policy or contract language and attach the documentation the payer named. Generic 'please reconsider' letters overturn very little; policy-cited appeals with clinical notes overturn a large share of medical necessity denials.

Denials

Claim Denial Management: Find the Cause, Fix the Process

Work the denial in front of you, then stop it from coming back.

Denials are not a billing problem. They are a diagnostic signal that something upstream — registration, authorization, documentation, coding, or contract interpretation — produced a claim the payer would not pay. Working a denial gets you paid once. Reading the pattern behind fifty denials gets you paid every time after that.

The industry average sits somewhere between 5 and 12 percent of claims denied on first submission, and roughly two thirds of those denials are recoverable. The problem is that most practices never recover them: the work is manual, the deadlines are short, and appeals compete with the daily queue of new claims.

This section separates the two jobs. The first is tactical — identify the denial from its CARC and RARC codes, decide whether it needs a correction or an appeal, and file within the payer's window. The second is structural: categorize denials by cause rather than by code, find the three that generate most of the dollar value, and change the process that produces them.

You will also find prior authorization here. It is technically a pre-service requirement rather than a denial, but authorization failures are one of the largest denial categories in 2026 and practices search for both together, so we keep them side by side.

Explore this section

Denial Management
Triage, root-cause categories, and the workflow that prevents repeats.
Appeals
Levels of appeal, deadlines, evidence, and letters that get overturned.

Frequently asked questions

What is the difference between a rejection and a denial?: A rejection never entered adjudication — the clearinghouse or payer bounced it for a format or eligibility error, and you can correct and resubmit it. A denial was adjudicated and refused, so it needs a corrected claim or a formal appeal within the payer's deadline.
How long do I have to appeal a denied claim?: Commercial payers commonly allow 90 to 180 days from the remittance date, Medicare allows 120 days for a redetermination, and some plans allow as little as 60. The remittance advice states the window; calendar it the day the denial posts.
Which denials should I work first?: Sort by recoverable dollars and by deadline, not by age. High-value denials with a clear fix and a closing appeal window come first; low-dollar denials with systemic causes belong in a process fix, not in the appeal queue.
What denial rate is acceptable?: Under 5% on first-pass submissions is a realistic target for most specialties. Anything above 10% usually points at front-end eligibility and authorization failures rather than coding.
Do appeal letters actually work?: Yes, when they cite the specific policy or contract language and attach the documentation the payer named. Generic 'please reconsider' letters overturn very little; policy-cited appeals with clinical notes overturn a large share of medical necessity denials.

More on denials and appeals

Denial code breakdowns, appeal letter structure, and root-cause patterns, published as we work through the code set.

Browse denial codes