How to reduce claim denials in your practice

Start with the denials you already have

Before changing anything, pull the denials from the last ninety days out of your practice management system or clearinghouse. Every electronic remittance (the 835 transaction) carries a claim adjustment reason code, or CARC, and often a remittance advice remark code, or RARC, that says why the payer paid less than billed. Those codes are the raw material. Group the denied lines by code, then by payer, then by billing provider, and attach the dollar value to each group.

The list is usually shorter than expected. A handful of codes account for most of the volume, and a different handful accounts for most of the dollars. High-volume, low-dollar denials eat staff time; low-volume, high-dollar denials are usually the surgical or infusion claims that a single missing authorization can sink. Decide which list you are attacking first, because the fix for each is different.

Where each reason code points

The code tells you which department owns the cause. That mapping is the whole point of the exercise, because a denial worked by the billing office and caused by the front desk will come back next month. Our denial codes guide goes through the common codes one by one; the short version is below.

• CO-16 (claim lacks information) and CO-4 (procedure inconsistent with modifier) usually point to registration or charge entry.
• CO-197 (precertification or authorization absent) and CO-27 (coverage terminated) point to the front desk and the eligibility workflow.
• CO-11 (diagnosis inconsistent with procedure), CO-50 (not deemed medically necessary) and CO-97 (bundled) point to documentation and coding.
• CO-29 (timely filing) and CO-18 (duplicate claim) point to the billing office itself.

Separate rejections, denials and underpayments

Three different things get lumped together under the word denial, and mixing them hides the real rate. A rejection was stopped at the clearinghouse or the payer’s front-end edits and never adjudicated; it can be corrected and resent the same day, and it should never sit in a queue. A denial was adjudicated and refused, and needs either a corrected claim or an appeal. An underpayment was adjudicated and paid, just at less than the contracted rate, and needs a contract check and a reconsideration request.

Count them separately. Your denial rate should be denied claims (or denied dollars) divided by claims adjudicated in the same period, with rejections excluded. If your system cannot tell the two apart, that is the first thing to fix, because a rejection rate that looks like a denial rate will send you chasing the wrong problem. According to the 2024 CAQH Index, about 12% of medical and dental claims were denied in 2023, so a practice that measures correctly has a rough industry yardstick to hold its own number against.

Fix the front end first

The largest share of avoidable denials is created before a claim exists. A wrong subscriber ID, an inactive plan, a missing referring provider NPI, a procedure that needed authorization and did not get it: none of these are billing errors in the usual sense, and none of them can be fixed by a better biller after the fact. They are fixed by changing what happens at scheduling and check-in.

Run a real-time eligibility check (the 270/271 transaction) for every scheduled visit, not just new patients, and run it again on the day of service for anything high-dollar. Verify demographics against the insurance card rather than the patient’s memory, and capture the plan name exactly, since many payers run several products with similar names and different claim addresses. Each of these steps takes seconds; each of them removes a category of denial you would otherwise pay someone to work.

Prior authorization: the denial you cannot fix afterward

CO-197 deserves its own workflow because it is the one front-end denial that almost never survives an appeal. If the payer required an authorization and none exists, the service is usually not payable and cannot be billed to the patient under most contracts. Build a short list of the services in your specialty that commonly require authorization, check it at scheduling, and make the authorization number and approved units required fields before the appointment is confirmed. The 2024 CAQH Index reports that providers spent about 24 minutes requesting an authorization by phone, fax or email against 16 minutes through a plan portal, so use the portal or the 278 transaction where the payer supports it. When the authorization is granted, record the units and the expiry date: an authorization for six visits does not cover the seventh, and one that expired in March does not cover April.

A final front-end check belongs to provider enrollment. Claims for a clinician who is not yet enrolled with a payer, or whose revalidation lapsed, reject or deny regardless of how clean the claim is. Keep an enrollment calendar per provider per payer and treat it as part of denial prevention rather than a credentialing chore.

Fix coding and documentation at the source

The second cluster of denials comes from the chart. Payers deny CO-11 when the diagnosis on the claim does not support the procedure, CO-50 when the service does not meet a coverage policy, and CO-97 or CO-4 when a bundled service is billed without a valid modifier or with the wrong one. Appealing these one at a time is slow and often fails; the durable fix is to change how the encounter is documented and coded.

Pull a small sample of the denied encounters and read the notes against the codes. Common findings are a diagnosis that was in the note but not on the claim, a modifier 25 or 59 appended by habit rather than because the documentation supports a separately identifiable service, and a service with a coverage determination the provider was unaware of. Feed each finding back to the specific provider with the specific chart. General reminders at a staff meeting change nothing; one provider looking at their own denied note changes behavior.

Work what still comes back, on a schedule

Even a well-run practice gets denials. The difference is what happens next. Denials need to be touched within a few days of the remittance posting, sorted by reason code and by deadline, and assigned to a named person. Every item should carry a next action and a date, not a note saying it was reviewed. Sorting purely by dollar value or age without reading the codes is how the same claim gets re-denied for the same reason.

Decide corrected claim versus appeal deliberately. Many denials are resolved faster with a corrected claim, and filing a formal appeal where a correction would do wastes the appeal window. Where an appeal is warranted, it should cite the payer’s own policy language and attach the documentation that addresses the stated reason. Track deadlines on both sides: the CMS Claims Processing Manual requires Medicare claims to be filed within one calendar year of the date of service, and the Medicare appeals process runs through five levels beginning with redetermination, each with its own clock. Commercial payers set their own limits, often shorter, in the provider contract.

How to reduce claim denials permanently: close the loop monthly

Working denials keeps cash moving. Reducing them requires a second, slower loop. Once a month, re-run the reason code report and compare it with the previous month. For each of the top codes, ask three questions: is the volume falling, has the upstream fix been made, and who owns it? A code that keeps appearing after the fix went in means the fix did not take, or the cause was somewhere else.

Track a small set of numbers and resist adding more. Write-offs deserve their own line because an untracked write-off is a denial that was quietly conceded. If a practice writes off timely-filing denials without anyone noticing, the denial rate looks better than the revenue does.

• Pull the reason code report on the same day each month so the periods are comparable.
• Give every top-five code a named owner in the department where it originates.
• Review write-offs by reason code alongside denials, not separately.
• Keep the payer dimension: a code rising with only one payer is usually a policy change, not a process failure.

Where an outside billing team fits

None of the above requires outsourcing. It requires someone to own the reason code report and the authority to change front-desk and documentation habits. Where a billing partner helps is in doing the daily denial work by code rather than by age, and in producing the monthly trend with volume and dollars attached. That is how DyBilling structures denial management: inside the client’s existing practice management system, with recurring codes traced back to the step that produced them and raised by a named account manager on the monthly review. Where a cause sits with front-desk registration, we say so rather than promise a number, because that fix belongs to your staff.