Chiropractic Billing Codes: CPT and ICD 10 Complete Guide
A clean chiropractic claim depends on getting two things right at the same time: the correct CPT code for the treatment performed and an ICD 10 diagnosis that supports why the treatment was medically necessary. Miss either piece and a payer has grounds to deny the claim, delay payment, or flag the practice for review. For a specialty where reimbursement often rides on a single manipulation code and a matching diagnosis pair, chiropractic billing codes are not a back office detail. They are the difference between steady cash flow and constant rework.
This guide walks through the CPT and ICD 10 codes that show up on nearly every chiropractic claim, how Medicare treats them differently from commercial payers, and where practices most often lose revenue to preventable coding mistakes.
Chiropractic billing codes are the CPT procedure codes and ICD 10 diagnosis codes used together to describe a visit on a claim form. CPT codes tell the payer what was done. ICD 10 codes tell the payer why it was done. Payers use that pairing to decide whether a service was medically necessary and whether it fits their coverage policy. When the codes are accurate and the documentation backs them up, claims tend to move through the system without friction. When they do not line up, the claim is far more likely to be denied, downcoded, or pulled for audit.
The core of chiropractic coding is the chiropractic manipulative treatment, or CMT, family of codes. These are Category I CPT codes maintained by the American Medical Association, and code selection depends entirely on how many spinal regions were treated during the visit, not on how many individual manipulations were performed.
| CPT Code | General Purpose | Billing Consideration |
|---|---|---|
| 98940 | CMT, spinal, 1 to 2 regions | Most common entry level CMT code |
| 98941 | CMT, spinal, 3 to 4 regions | Documentation must name each region treated |
| 98942 | CMT, spinal, 5 regions | All five spinal regions must be documented |
| 98943 | CMT, extraspinal, one or more regions | Medicare does not cover this code |
Only one CMT code from 98940 through 98942 should be reported per encounter. Practices sometimes also bill therapeutic codes such as 97110, 97140, or 97012 alongside CMT when the payer allows it, but coverage for these additional services varies widely and should always be confirmed with the specific plan.
CMS recognizes five spinal regions for CMT billing: cervical, thoracic, lumbar, sacral, and pelvic. The code chosen reflects the total number of distinct regions treated in that visit, regardless of how many adjustments were made within a region. Treating the cervical and lumbar regions is two regions, which supports 98940. Adding the thoracic region brings the count to three, which moves the claim to 98941. Documentation should name the specific regions treated rather than simply stating a region count, since a generic note is one of the more common reasons a payer questions a claim.
For Medicare, chiropractic claims require two diagnoses working together. The primary diagnosis identifies the spinal subluxation using codes M99.00 through M99.05, which describe segmental and somatic dysfunction by spinal region. The secondary diagnosis identifies the underlying neuromusculoskeletal condition, such as pain, radiculopathy, or a related musculoskeletal disorder, that explains why treatment was needed. The level of subluxation on the primary diagnosis must be supported by exam findings or imaging, and it should be coded to the highest level of specificity available.
| ICD 10 Code | Region | Note |
|---|---|---|
| M99.00 | Head region | Primary subluxation diagnosis |
| M99.01 | Cervical region | Primary subluxation diagnosis |
| M99.02 | Thoracic region | Primary subluxation diagnosis |
| M99.03 | Lumbar region | Primary subluxation diagnosis |
| M99.04 | Sacral region | Primary subluxation diagnosis |
| M99.05 | Pelvic region | Primary subluxation diagnosis |
Because coverage policies for chiropractic diagnosis coding can vary by payer and by Medicare Administrative Contractor, practices should treat any specific diagnosis list as a starting point and confirm current requirements against the applicable Local Coverage Determination before relying on it.
A CPT code without a supporting ICD 10 pairing rarely survives payer review. The number of spinal regions reflected in the CPT code should match the number of subluxation diagnoses submitted, and the secondary diagnosis should reflect the actual clinical reason for care, not a placeholder pain code. When a claim lists 98941 for three regions but only two subluxation diagnoses appear, that mismatch is exactly the kind of detail a payer system is built to catch.
Medicare only covers chiropractic manual manipulation of the spine, using CPT codes 98940 through 98942, when it is billed with the AT modifier to indicate active or corrective treatment. Claims for these codes submitted without the AT modifier are treated as not medically necessary. Once a patient reaches maximum therapeutic improvement for a condition, continued care is generally considered maintenance therapy, which Medicare does not reimburse, even with the AT modifier attached. Medicare does not cover CPT 98943 for extraspinal manipulation under the chiropractic benefit. Because chiropractic coverage rules are issued through Local Coverage Determinations, exact documentation expectations can differ somewhat by Medicare Administrative Contractor jurisdiction, so practices should verify current LCD guidance for their region.
Every subluxation diagnosis on a Medicare claim needs to be supported by physical exam findings or imaging that a reviewer could point to if the claim were audited. Notes should specify the exact regions treated, the clinical findings that justify treatment, and a plan of care with goals, since vague or templated notes are a frequent reason claims get pulled for further review.
- Billing 98942 when documentation only supports three or four regions
- Leaving off the AT modifier on Medicare CMT claims that involve active treatment
- Submitting a subluxation diagnosis that is not supported by exam findings
- Continuing to bill active care codes once a patient has reached maximum improvement
- Pairing a CPT code with a diagnosis count that does not match the regions treated
Quick Reference: Claim Review Checklist
- CPT code matches the documented number of spinal regions treated
- Primary diagnosis uses the correct M99.0x code for each region billed
- Secondary diagnosis reflects the actual underlying condition
- AT modifier is present on Medicare claims involving active treatment
- Documentation supports medical necessity, not ongoing maintenance care
- Payer specific rules have been checked for any therapy codes billed alongside CMT
A patient is treated for cervical and lumbar subluxation, so the visit is billed as 98940 with modifier AT. The documentation, however, only mentions cervical findings in detail and lists the lumbar region without exam support. On review, the payer questions the lumbar portion of the claim, since the second region billed is not clearly supported in the note. The fix is not a coding change, it is a documentation gap. This is a common scenario where accurate CPT selection alone is not enough. The clinical note has to carry the same level of detail as the billed code.
Most chiropractic denials trace back to a small set of recurring issues: a missing AT modifier, a subluxation diagnosis that outpaces the documentation, or a CPT code that does not match the regions actually described in the note. Building a habit of checking these three points before every submission prevents a large share of avoidable denials.
Reduce Denials Tied to Chiropractic Coding
Care RCM works with chiropractic practices on accurate CMT and spinal region coding, AT modifier compliance, visit limit and eligibility tracking, denial management, and SOAP note review to support medical necessity. If claim denials, AT modifier questions, or diagnosis pairing issues are creating rework for your team, our Chiropractic Billing Services are built specifically around these challenges.
Coding accuracy is only part of the picture. Payer specific rules, changing LCDs, visit limits, and eligibility checks all add administrative load on top of coding itself. Practices that are seeing rising denial rates, slow reimbursement, or staff time consumed by claim rework often benefit from specialized support rather than trying to keep every payer rule current in house.
Frequently Asked Questions
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CPT 98941, covering CMT for three to four spinal regions, is widely reported as the most frequently billed CMT code in chiropractic practices.
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Medicare requires the AT modifier on CPT codes 98940 through 98942 whenever the service represents active or corrective treatment. Without it, the claim is treated as not medically necessary.
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Medicare specifically requires a primary subluxation diagnosis paired with a secondary diagnosis describing the underlying condition. A CPT code alone does not establish medical necessity.
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No. Commercial payers and Medicaid programs can set their own diagnosis and documentation requirements, so rules should always be confirmed against the specific payer or Medicare Administrative Contractor.
Accurate chiropractic billing codes protect both patient care and practice revenue. Getting CPT and ICD 10 pairing right, applying the AT modifier correctly, and keeping documentation aligned with what is billed all reduce denials and speed up reimbursement. If your practice wants a closer look at how coding and documentation are affecting your claims, Care RCM’s Chiropractic Billing Services team can review your current process and identify where revenue may be slipping through.
Optimize Your Chiropractic Practice Revenue
Stop losing revenue to CMT coding errors, AT modifier issues, and subluxation claim denials. Our specialized chiropractic billing solutions maximize clean claim rates and streamline compliance. Contact our billing experts today and feel the difference in your cash flow.
Contact Us NowDisclaimer: Denial rates, performance benchmarks, and revenue improvement figures referenced in this guide reflect publicly available information, industry research, and Care RCM professional RCM experience as of June 2026. Individual practice outcomes vary based on payer mix, specialty volume, existing billing infrastructure, and claim complexity. All CPT code, modifier, and compliance guidance reflects current CMS and AMA standards. Chiropractic Billing Services references are intended as general guidance only; specific coding and bundling rules should be verified with a qualified billing specialist for your practice.