Billing guide · Stop 03 of 05
Chiropractic denial codes, and what to do with each one.
Every denied line on your remittance carries a reason code. Some point to paperwork your office can fix today. Others point to a judgment only your provider can make. Sorting each one into the right pile decides who fixes it.
Read the group code first
A denial on your electronic remittance advice is a pair: a group code and a claim adjustment reason code, or CARC, such as CO-50. The group code says who carries the amount. CO means your practice does, and it is generally not billed to the patient; for a Medicare patient it never is. PR means the patient does. The reason code says why. Often a remittance advice remark code, or RARC, adds the detail you need to act on it. If those terms are new, start with how to read an ERA.
One check before you work any denial: make sure it is a denial. A claim the clearinghouse or payer refused before processing is a rejection, it never appears on the remittance, and it needs a different fix. The guide to rejected and denied claims explains the difference.
Two kinds of denial
Sort every denial into one of two piles before anyone touches it.
Administrative denials are paperwork: a wrong ID, a missing field, a missing authorization, a provider the payer has not finished enrolling. Your office can fix them without asking your provider anything.
Clinical denials question the care itself: was it necessary, were there too many visits, does the diagnosis support the service. The answer starts with what the signed note supports, and that call belongs to your provider.
Coding denials sit between the two. Your office can spot a missing modifier or a mismatched diagnosis. Whether the note supports a different code or modifier is your provider’s decision.
Administrative denials your office can fix
| Code | What the payer is saying | Common cause | Next step |
|---|---|---|---|
CO-16 | The claim lacks information or has a submission or billing error | A missing or invalid field: the initial treatment date, a rendering provider identifier, a subscriber detail | Read the remark code; payers must send one, and it names the problem. With Medicare’s MA130 the claim counts as unprocessable: send a new claim, because there are no appeal rights. |
OA-18 | Exact duplicate claim or service | A claim sent again as new instead of as a corrected claim, or resent while the first was still in process | Do not resend. Check the first claim’s status, and send changes as a corrected claim. |
CO-22 | Another payer may cover this under coordination of benefits | The payer’s records show other coverage that pays first | Confirm coverage order with the patient and the payer, bill the primary payer, then come back with its remittance. |
CO-27 | Expenses incurred after coverage ended | The patient’s plan ended before the visit | Ask the patient for current coverage. Verify eligibility before the next visit. |
CO-29 | The time limit for filing has expired | The claim reached the payer after the filing deadline, often after sitting rejected | Appeal only if you have proof of timely filing, such as an acceptance report dated inside the deadline. |
CO-109 | Not covered by this payer; send it to the correct payer | The plan routes claims elsewhere, such as a chiropractic benefit run by a separate specialty vendor | Find the right payer from the card or the eligibility response and file there. |
CO-197 | Precertification, notification or authorization was absent | The plan requires an authorization or a visit plan on file before visits, or after a set number of them | Ask whether the payer accepts a retroactive authorization. Add the requirement to your eligibility check. |
CO-B7 | The provider was not eligible to be paid for this service on this date | A new associate saw patients before their enrollment with the plan took effect | Confirm the enrollment effective date with the payer, then rebill the visits it covers. |
Coverage and plan limits
These denials say the plan does not pay for the service, or not for this many. The group code decides whether the patient owes it.
| Code | What the payer is saying | Common cause | Next step |
|---|---|---|---|
96 | Non-covered charge | A service the plan excludes, such as maintenance care or a therapy the plan does not cover | As PR-96, the patient owes it. As CO-96, your practice carries it unless your contract allows otherwise. |
204 | Not covered under the patient’s current benefit plan | The patient’s plan has no chiropractic benefit, or excludes this service | Same as 96: the group code decides. Check benefits before the first visit. |
119 | The benefit maximum for this period has been reached | The patient used the plan’s yearly visit allowance | Check remaining visits at every eligibility check, and tell the patient before the limit, not after. |
The guide to what the patient owes after insurance covers billing these amounts to the patient.
Coding and bundling denials
Your office finds these; your provider confirms what the note supports before anything changes.
| Code | What the payer is saying | Common cause | Next step |
|---|---|---|---|
CO-4 | The procedure code is inconsistent with the modifier used | A modifier that does not fit the code, or one the payer’s policy requires that is missing, such as the AT modifier for active treatment | If the note supports the right modifier, send a corrected claim with it. |
CO-11 | The diagnosis is inconsistent with the procedure | A CMT line whose diagnoses do not support the regions billed, such as a missing segmental dysfunction code for a region | Your provider confirms the diagnoses in the note; correct the claim to match. |
CO-97 | This service is included in the payment for another service | An office visit billed the same day as CMT without a separately identifiable reason documented | A modifier belongs on the visit only when the note documents a significant, separate evaluation. |
CO-236 | This code is not compatible with another code billed the same day under the National Correct Coding Initiative | Manual therapy billed on the same region as the adjustment | A modifier belongs on the line only when the note shows a different region. |
Clinical denials your provider owns
| Code | What the payer is saying | Common cause | Next step |
|---|---|---|---|
CO-50 | The payer does not consider the service medically necessary | The note does not show active treatment: no measurable goals, no progress, care that reads as maintenance | Your provider reviews the note. If it supports the care, appeal with the records. If it does not, accept the denial. |
CO-151 | The information submitted does not support this many services, or this frequency | More visits than the payer’s policy expects for the condition, without a documented reason | Send the treatment plan and progress notes if they justify the frequency. |
CO-167 | The diagnosis is not covered | A diagnosis the plan’s chiropractic policy does not accept as primary | Your provider confirms the diagnosis the note supports. |
One rule holds for every clinical denial: a signed note is never changed to win an appeal. Your provider decides what the note supports, and the appeal says what the note says.
Medicare and the AT modifier
Medicare pays for chiropractic manipulation only as active, corrective treatment of a subluxation, billed with CMT codes 98940, 98941 or 98942. Each CMT line for active treatment carries the AT modifier. Maintenance therapy is not considered medically reasonable or necessary. A line without the AT modifier is treated as maintenance and denied, and a line with it still needs a note that supports active treatment.
When your provider expects Medicare to deny a visit as maintenance, the patient can sign an Advance Beneficiary Notice before the visit, and the claim carries the GA modifier. If Medicare then denies the visit, the patient owes it. Without a valid notice, your practice carries the denial. Some commercial plans follow similar rules for active treatment; check each payer’s chiropractic policy.
Correct, reconsider or appeal
Once you know the reason, pick the route that fits it:
- Corrected claim. You billed it wrong: a missing modifier, a wrong diagnosis, a missing field. For commercial payers, send a replacement claim that cites the payer’s claim control number from the remittance; sent as a new claim, it earns a duplicate denial. Medicare Part B takes no replacement claims, so a clerical error there is fixed through a reopening.
- Reconsideration. You billed it right and the payer applied its rule wrong, such as an allowed amount below your contract rate. Many payers offer a first-level review before a formal appeal.
- Appeal. A formal request with records, usually for clinical denials. Each payer sets its appeal deadline in its provider manual or your contract. Put that date on the claim the day the denial arrives.
Track the pattern, not only the claim
A denial you fix once is a claim. The same denial from the same payer three times is a rule your claims do not follow yet. Once a month, count denials by payer and reason code. Each repeat earns a check before filing: verify remaining visits for the plan that keeps returning 119, confirm the authorization for the plan that keeps returning 197, check the modifier for the plan that keeps returning 4. Fewer denials come back when the check moves ahead of the claim.
How Claims Native works denials
We sort every denial into paperwork we fix ourselves and questions only your provider can answer. A clinical question goes to your provider once, with the note and the payer’s exact words; your provider decides what the note says. A person reviews every reconsideration, appeal and payer dispute before it goes out. Then we record what the payer needed, so the next claim goes out the way that payer wants it.
Sources
- X12, Claim Adjustment Reason Codes. X12 maintains the code list and updates it three times a year; check the current wording there.
- X12, Claim Adjustment Group Codes.
- X12, Remittance Advice Remark Codes.
- CMS, Medicare Benefit Policy Manual, Chapter 15, sections 30.5 and 240. Chiropractic coverage, maintenance therapy and the AT modifier.
- CMS, MLN Matters SE1601: Medicare coverage of chiropractic services.
- First Coast Service Options, Tips to prevent CARC B7.
- CMS, Health Care Payment and Remittance Advice. CO assigns responsibility to the provider; PR to the patient.