Claim Denial Management: How to Reduce, Work and Appeal Denials

A denial is a message from a payer. Sometimes the message is “you made a mistake,” sometimes it is “we disagree,” and sometimes it is “we need more information.” Practices that treat denials as bad luck keep getting them. Practices that read them as feedback slowly get fewer of them.

Our earlier article on common medical billing mistakes covers what causes denials at the front end. This one is about what to do once a denial has landed: how to read it, how to decide what to fight, and how to build a routine so the same ones do not keep coming back.

Rejections versus denials

The difference matters because the fix is different.

• Rejections never made it into the payer’s adjudication system. The clearinghouse or the payer’s front-end edits caught a problem such as a missing field, an invalid ID or a bad format. Fix the data and resubmit. There is usually no appeal because there was no decision.
• Denials were processed and the payer decided not to pay all or part of the claim. These need a corrected claim or a formal appeal, and they come with deadlines.

How to read a remittance

Every adjustment on an electronic remittance (835) or EOB has three parts that tell you what happened:

• Group code. CO (contractual obligation) usually means the practice cannot bill the patient for that amount. PR (patient responsibility) means the amount belongs to the patient, as a deductible, copay or coinsurance. OA (other adjustment) and PI (payer initiated reduction) are used in other cases.
• CARC (Claim Adjustment Reason Code). A standard code for why the amount was adjusted.
• RARC (Remittance Advice Remark Code). An optional extra code that adds detail, for example the specific piece of information that is missing.

A few CARCs show up constantly. These meanings come from the code lists that the X12 committee maintains, and CMS publishes the RARC list for Medicare:

CARC	Typical meaning	Where the fix usually starts
CO-16	Claim or service lacks information needed for adjudication	Read the RARC. Add the missing item and resubmit
CO-18	Exact duplicate claim or service	Check whether the original was paid before doing anything else
CO-29	The time limit for filing has expired	Look for proof of timely filing before the deadline
CO-50	Not deemed a medical necessity by the payer	Check the diagnosis link and documentation, then appeal if supported
CO-97	Payment is included in the allowance for another service	Check bundling edits and modifiers
CO-197	Precertification or authorization absent	Look for a retro-authorization route, or appeal with proof
PR-1, PR-2, PR-3	Deductible, coinsurance, copay	Not an error. Bill the patient

Descriptions vary slightly in the official wording and payers apply them differently, so always read the code list and the payer’s own policy before acting on a code.

A triage method that works

You will never have time to chase every denial equally, so sort them.

1. Deadline first. Record each payer’s appeal window the day you set up the account. For traditional Medicare, the first level of appeal (a redetermination by the Medicare Administrative Contractor) must generally be requested within 120 days of receiving the initial determination. Commercial plans typically set their own windows, often 60 to 180 days, so read your contracts.
2. Value second. Within the same deadline band, work the bigger balances first.
3. Fixability third. Quick corrections (a missing modifier, a wrong date) go out the same day. Appeals that need clinical documentation get scheduled.
4. Write off last, and on purpose. Some denials are legitimate. Record why, so the pattern is visible.

Writing an appeal that gets read

An appeal is a short, specific document, not a complaint. The reviewer is working through a stack, so make the case easy:

• State the claim identifiers, date of service, code and the denial reason in the first lines.
• Say precisely why the denial is wrong, and cite the payer’s own policy or the contract clause if you can.
• Attach only what proves the point: the relevant part of the note, the authorization number, the proof of timely filing, the corrected claim.
• Keep a copy and the submission date. If the first-level appeal fails and you still believe you are right, ask what the next level is and what its deadline is.

Fix the cause, not just the claim

This is the step that separates practices whose denial rate falls from those whose rate stays flat. Every time a denial is resolved, record the cause in a short, consistent list, such as eligibility, authorization, coding, documentation, timely filing, payer error or patient information. Review the totals each month, by payer.

The pattern is usually obvious within a couple of months. If one payer keeps denying a particular code for medical necessity, the fix may be in the note template. If authorization denials cluster around one service, the front desk probably does not have a list of what needs approval. If “patient not eligible” is common, eligibility checks are not happening before the visit. That last one is exactly what our eligibility verification work prevents.

A weekly rhythm

• Daily: work rejections and quick corrections so nothing sits.
• Weekly: review new denials, triage by deadline and value, send appeals and log causes.
• Monthly: review denial rate and top reasons by payer, and decide which one process change would remove the most denials.
• Quarterly: check for underpayments against contracted rates, and look at which payers deny more than their peers.

What to measure

Track the denial rate (claims denied divided by claims submitted), the appeal success rate (appeals that recover payment divided by appeals filed) and the average days to resolve a denial. A falling denial rate with a flat appeal rate usually means the front end is improving. A flat denial rate with a high appeal success rate means you are winning fights that you should not have to have.

If you would rather not run this yourself, our denial management service covers it from reading the code to fixing the cause, and our A/R follow-up keeps unpaid claims from aging in the background.

Corrected claim, reconsideration or formal appeal?

These three terms get mixed up, and choosing the wrong route wastes weeks. A corrected claim (usually a replacement claim with the right frequency code) fixes an error on the claim itself, such as a wrong code, modifier or date. A reconsideration or first-level review asks the payer to look again, often with extra documentation, when the data was right but the decision was not. A formal appeal follows the payer’s written process and deadlines, and usually has more than one level.

Always check the payer’s instructions for which route applies to a given denial reason. Sending a corrected claim when the payer wants an appeal, or the other way round, is a common reason a good case gets closed as untimely.