Chiropractic Medicare billing
Chiropractic Medicare Billing: The Rules That Get Claims Denied
Medicare pays chiropractors for one thing, and denies almost everything else for a fixable reason. Here are the rules behind the denials, and how we catch them before your claims go out.
What’s covered
Medicare covers exactly one chiropractic service, and it’s narrower than most practices think.
Under the chiropractic benefit, Medicare Part B covers manual manipulation of the spine to correct a subluxation, and nothing else. It does not pay for the exam, the X-rays, the therapies, the supplies, or anything extraspinal. That single covered service is billed with three CPT codes, and every one of them lives or dies on documentation that proves the care is active, not maintenance.
Get the codes, the modifier, the dates, and the diagnosis order exactly right and the claim pays. Miss any one of them and Medicare denies it, usually with a code that tells you precisely what went wrong, if you know how to read it. Below is the rulebook, the way an experienced chiropractic biller reads it, and how our billing service catches each failure before the claim ever leaves your practice.
98940 / 98941 / 98942
- 98940: CMT, spinal, 1 to 2 regions
- 98941: CMT, spinal, 3 to 4 regions
- 98942: CMT, spinal, 5 regions
Payable only with the AT modifier and documentation that substantiates a subluxation.
98943 & everything else
- 98943: extraspinal CMT (head, extremities, ribs, abdomen)
- Exams & E/M, X-rays, and the X-ray reading
- Therapies (97110, 97140), supplies, supports
Statutorily excluded. Bill the patient, but use the right notice first (see ABN below).
The AT modifier
No AT modifier? Medicare reads your CMT as maintenance, and denies it.
The AT modifier (Active/Corrective Treatment) is the single most important element on a chiropractic Medicare claim. Append it to 98940, 98941, or 98942 to tell Medicare the manipulation is meant to improve the patient’s condition. Leave it off and the MAC treats the visit as maintenance care (which is never covered) and denies it as not medically necessary.
That denial comes back as CO-50: “non-covered services because this is not deemed a medical necessity by the payer.” It is one of the most common chiropractic Medicare denials, and one of the most avoidable. The flip side matters just as much: appending AT to a visit that is genuinely maintenance is a compliance violation that invites recoupment and audit. The AT modifier is not a checkbox to make claims pay. It is a clinical attestation, and it has to be true.
Where the line sits (active vs. maintenance) is a clinical decision the provider documents. Our job is to make sure the claim matches the documentation: AT on the visits the note supports as active care, and an honest patient bill on the rest. We never quietly add AT to make a denial disappear.
Denial codes
Chiropractic Medicare denial codes (CO-50, CO-16, CO-11): what each one is really telling you.
A denial code is a diagnosis. Each one points at a specific failure upstream, and once you can read them, the same handful of fixes clears the vast majority of chiropractic Medicare rejections.
Not medically necessary
Almost always the missing AT modifier. Medicare is treating the CMT as maintenance. Sometimes documentation that doesn’t show active care or measurable improvement.
Claim lacks information
Something required is missing, most often the initial treatment date in Item 14, or PART/X-ray documentation that substantiates the subluxation.
Dx inconsistent with procedure
The primary diagnosis or its pointer doesn’t support the spinal region billed: the subluxation code and the CMT region disagree.
None of these are mysteries. They’re the symptoms of four upstream rules, covered next: the initial treatment date, PART documentation, diagnosis order, and the AT modifier.
Initial Tx date
The date active care began belongs in Item 14, every time.
Medicare requires the date of the initial treatment, or the date of the exacerbation of an existing condition, on every active-care CMT claim. It goes in Item 14 of the CMS-1500 form (or its electronic equivalent in any EHR). This date anchors the episode of care and tells Medicare the manipulation is part of an active treatment plan with a beginning, not open-ended maintenance.
Leave it off and the claim is missing required information, and the whole thing bounces back as CO-16. It’s a clerical miss with a clinical-sounding denial, and it’s one of the easiest to prevent and the easiest to overlook in a busy practice.
The PART exam
PART is how you prove the subluxation is real.
A subluxation has to be demonstrated, not just stated. Medicare accepts either an X-ray or a physical exam to substantiate it, and the physical-exam standard is the PART framework. Document at least two of the four PART criteria, and at least one of the two must be Asymmetry or Range-of-motion. The note then needs the exact level of the subluxation and a plan of care with measurable goals.
2 of 4, and one must be A or R
Pain and tissue-tone findings alone don’t carry the claim; Medicare wants objective evidence of the misalignment or the lost motion. The note must also state the precise subluxation level and tie it to a plan of care with goals you can measure visit-to-visit.
Where an X-ray is used instead, its date has to support the episode. Too old or undated, and the documentation fails, surfacing as CO-16.
Diagnosis order
The subluxation is the primary diagnosis, and it has to match the region.
On a Medicare CMT claim the primary diagnosis must be the subluxation, coded in the M99.0x family (segmental and somatic dysfunction), and it must correspond to the spinal region you actually manipulated. The neuromusculoskeletal complaint that justifies the care (the M54.x back and neck pain codes, for example) is a supporting secondary diagnosis. It cannot stand alone as primary for CMT.
Then the diagnosis pointers have to line up: the CMT line points to the subluxation level that matches its region. When the primary diagnosis, the region, and the pointer disagree, Medicare returns CO-11: diagnosis inconsistent with the procedure. It’s a quiet error that a generalist biller, working from a template, misses constantly.
ABN & maintenance
When care becomes maintenance, the ABN is what protects the practice.
Active care eventually reaches a plateau. When the goal shifts from improving the condition to preventing deterioration (or holding the patient where they are), the care becomes maintenance, and Medicare won’t pay. That isn’t a billing problem; it’s a coverage line. The mistake is pretending it isn’t.
Before delivering maintenance CMT (or any non-covered service like extraspinal 98943), the practice should issue an Advance Beneficiary Notice of Noncoverage (ABN, form CMS-R-131). The ABN tells the patient Medicare is expected to deny the service and that they may be responsible for it, so they can decide to proceed and pay. Skip it, and you may be unable to bill the patient at all, and the cost lands on the practice.
The honest path: active care → billed to Medicare with AT and full documentation. Maintenance and non-covered services → ABN on file, then billed to the patient. Two clean tracks, never blurred. That’s how a practice stays both paid and compliant, and it’s exactly the line our coordinators help you hold.
Claim scrubbing
Every rule above is a scrub check, run before the claim is ever submitted.
A “clean claim” that wasn’t rejected can still be denied. We scrub each chiropractic Medicare claim against the exact failure points on this page: the AT modifier, the initial treatment date, PART and X-ray documentation, and the diagnosis order. That way it pays the first time instead of bouncing back weeks later.
And it’s consultative, not just defensive. The same review that prevents denials catches the money generalists miss: undercharged E/M visits, codes left off the claim, CPT lines priced below the fee schedule. Many of our clients run multi-specialty centers, so the same coordinator also bills the therapy (97110, 97140), massage, acupuncture, and nurse-practitioner visits under your roof, with the Medicare-specific rules applied correctly across all of them. It’s all one flat fee, laid out on our pricing page.
Proof
The expertise shows up in the collections.
“In practice over 30 years, I have never found a more professional, knowledgeable company. I have a dedicated person accessible at all times, and they’re compatible with my EHR so I have no extra steps.”
“ACB has been instrumental in cleaning up our accounts receivable, helping us transition between software, and staying on top of all our billing. Knowledgeable, and most importantly, effective.”
“I used to spend a lot of time calling insurance companies when claims weren’t paid. Now they’re part of my team, so I can focus on patient care. Highly recommend.”
FAQ
Chiropractic Medicare billing, answered.
The AT (Active/Corrective Treatment) modifier tells Medicare the spinal manipulation is intended to improve the patient’s condition, not just maintain it. Without AT on 98940, 98941, or 98942, Medicare treats the visit as maintenance care (which it never covers) and denies it as not medically necessary (CO-50). It should only be applied when the documentation genuinely supports active care; using it on a maintenance visit is a compliance violation.
No. The Medicare chiropractic benefit covers only manual manipulation of the spine to correct a subluxation: codes 98940, 98941, and 98942. Extraspinal manipulation (98943, for the head, extremities, ribs, and abdomen) is statutorily excluded. It can be billed to the patient, but you should issue an ABN first so the patient understands Medicare will not pay.
CO-16 means the claim is missing required information, separate from the AT issue. The most common cause on chiropractic claims is a missing initial treatment date in Item 14 of the CMS-1500 (the date active care began or the condition was exacerbated). It can also mean the PART exam findings or X-ray date that substantiate the subluxation aren’t documented. Both are things we verify on every claim before submission.
The subluxation must be the primary diagnosis, coded in the M99.0x family (segmental and somatic dysfunction) and matched to the spinal region treated. The pain or neuromusculoskeletal complaint (for example an M54.x code) is a supporting secondary diagnosis and cannot stand alone as primary for CMT. If the primary diagnosis, the region, and the diagnosis pointers don’t agree, Medicare returns CO-11.
Issue an Advance Beneficiary Notice of Noncoverage (ABN, form CMS-R-131) before delivering care Medicare is expected to deny: maintenance CMT and non-covered services like 98943. The ABN documents that the patient was told Medicare likely won’t pay and agreed to be responsible. Without it on file, you may be unable to bill the patient for that service, so the cost falls on the practice. We help you keep active care and maintenance care on two clean, compliant tracks.
Pricing
All of this, for 7% of net collections.
Medicare scrubbing, denials and appeals, the AT-and-documentation review on every CMT claim, your dedicated coordinator, and the consultative revenue work. It’s all included in one performance-based fee: 7% of net collections, or a $1,500/month minimum, whichever is greater. All-inclusive, month-to-month, no contract. See the full breakdown and run the numbers on our pricing page.
Official sources
Where these rules come from
Every Medicare rule on this page is drawn from these primary CMS sources. Coverage policy and documentation requirements change, so confirm the current rule before billing.
- CMS · Billing & Coding: Chiropractic Services (A56273)
- CMS · Local Coverage Determination: Chiropractic Services (L37254)
- Medicare.gov · Chiropractic services coverage
- CMS · Advance Beneficiary Notice of Noncoverage (ABN, Form CMS-R-131)
Billing rules also vary by state. See our state-by-state chiropractic billing guides. Each covers the local auto-injury, Workers’ Comp and Medicaid rules, cited to the governing statute.
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