What Is CPT Code 98940?
CPT code 98940 is the chiropractic manipulative treatment (CMT) code used when a chiropractor performs spinal manipulation on one or two spinal regions during a single session. It is the lowest-tier CMT code in the 98940-98942 family and is selected based on the number of spinal regions treated, not the number of individual adjustments performed. The five recognized spinal regions for CMT billing are cervical, thoracic, lumbar, sacral, and pelvic.
- How it differs from 98941 and 98942: CPT 98940 covers one to two spinal regions. CPT 98941 covers three to four regions, and CPT 98942 covers all five. Billing the wrong tier based on the number of regions treated is the most common CMT coding error.
- Medicare AT modifier requirement: Every Medicare CMT claim for 98940 must include the AT modifier to indicate active corrective treatment rather than maintenance care. Claims submitted to Medicare without the AT modifier are denied automatically.
- 2026 reimbursement: Medicare reimburses CPT 98940 at approximately $28 nationally before geographic (GPCI) adjustment, based on the 2026 non-QP conversion factor of $33.4009. CMT RVUs for 2026 are slightly reduced, but the 3.26% increase in the conversion factor offsets the reduction, leaving reimbursement roughly flat compared to 2025.
What CPT Code 98940 Actually Covers
The American Medical Association (AMA) defines CPT 98940 as chiropractic manipulative treatment (CMT) involving one to two spinal regions. CMT is a hands-on manual therapy technique in which the chiropractor applies a controlled force to specific spinal joints to correct subluxation, restore joint mobility, reduce nerve interference, and improve neuromusculoskeletal function. For a complete reference of all chiropractic billing codes including the full CMT family, E/M codes, and therapeutic modalities, see our chiropractic CPT codes guide.
The code is selected based entirely on how many of the five recognized spinal regions the chiropractor treats during the visit. Those five regions are cervical, thoracic, lumbar, sacral, and pelvic. If the chiropractor adjusts the cervical and lumbar regions in a single session, that is two regions and the correct code is 98940. If the chiropractor adjusts only the lumbar region, that is one region and the code is still 98940.
One question we hear constantly from chiropractic practice managers is why their CMT claims get paid at the 98940 rate when they thought they billed for more regions. In our experience matching providers with billing partners, the issue is almost always documentation: the operative note does not clearly identify which specific spinal regions were treated, so the payer defaults to the lowest tier. The code selection must be supported by documentation that names the regions, not just the vertebral levels or the number of adjustments.
A critical distinction: 98940 covers only spinal manipulation. If the chiropractor also treats extraspinal regions (such as extremity joints), that is reported separately under CPT 98943. And if the chiropractor performs other therapeutic services during the same visit, such as electrical stimulation, therapeutic exercises, or manual therapy, those are billed under their own CPT codes in addition to 98940, subject to bundling rules and payer-specific policies.
How Does CPT 98940 Compare to 98941 and 98942?
The CMT code family is structured by the number of spinal regions treated, and the reimbursement increases with each tier. Selecting the correct code is straightforward in principle (count the regions) but causes problems in practice when documentation does not clearly support the tier billed. Here is how the three spinal CMT codes compare in 2026.
| CPT Code | Spinal Regions | Medicare Payment (approx.) | Common Use | AT Modifier Required (Medicare) |
|---|---|---|---|---|
| 98940 | 1 to 2 regions | ~$28 | Localized pain (e.g., cervical or lumbar only) | Yes |
| 98941 | 3 to 4 regions | ~$38 | Multi-region complaints (e.g., cervical + thoracic + lumbar) | Yes |
| 98942 | 5 regions | ~$47 | Full-spine adjustment | Yes |
| 98943 | Extraspinal (1 or more) | Varies by payer | Extremity joints (shoulder, knee, etc.) | No (not covered by Medicare) |
The 98941 allowed rate is approximately 35% higher than 98940, which is why the difference between billing one-to-two regions versus three-to-four regions has a real revenue impact across a high-volume chiropractic practice. That revenue gap is also why upcoding from 98940 to 98941 is one of the most common audit triggers in chiropractic billing. If the documentation only supports two regions, the claim must be filed as 98940 regardless of what the chiropractor intended to treat.
Across the billing companies we vet, the practices with the cleanest CMT billing are the ones whose providers document each spinal region by name in the SOAP note at the time of service, not retroactively. When the documentation says “cervical, thoracic, and lumbar adjustment,” 98941 is defensible. When it says “spinal manipulation x3,” the payer has no way to confirm the regions and may downcode to 98940.
What Is the AT Modifier and Why Does Medicare Require It?
The AT modifier (active treatment) is required on every Medicare chiropractic claim for CPT 98940, 98941, and 98942. It tells Medicare that the treatment is active and corrective, meaning the patient has not yet reached maximum therapeutic benefit and measurable improvement is still expected. Without the AT modifier, Medicare denies the claim automatically because the system reads it as maintenance care, which Medicare does not cover.
Medicare coverage for chiropractic services is limited to manual manipulation of the spine to correct a subluxation. That is the only chiropractic service Medicare Part B covers. Any other services the chiropractor provides during the same visit, including therapeutic exercises, electrical stimulation, ultrasound, or manual therapy, are not covered by Medicare even when they are medically appropriate. This means a Medicare chiropractic claim should typically contain only the CMT code (98940, 98941, or 98942) with the AT modifier and a subluxation diagnosis code.
The subluxation must be documented either by X-ray taken within a reasonable time frame or by specific physical examination findings that meet Medicare definition of subluxation. The documentation must describe asymmetry or misalignment, range of motion abnormality, tissue or tone changes, and the specific spinal segment affected. Vague notes such as “subluxation present” without objective findings do not meet Medicare requirements and leave the claim vulnerable on audit.
Providers often come to us after a pattern of Medicare CMT denials with no clear explanation. When we help them trace the issue, it is almost always one of three problems: the AT modifier was missing, the diagnosis code did not support subluxation, or the documentation did not contain objective findings to substantiate active treatment versus maintenance care. Each of these is preventable with the right claim-level review before submission.
CMT billing errors cost chiropractic practices in two ways: denied claims from missing modifiers or weak documentation, and audit exposure from upcoding that the chart notes cannot support. If your practice is losing revenue to avoidable CMT denials or you cannot keep up with payer-specific documentation rules, a specialized chiropractic billing partner fixes the problem at the source. Get matched with vetted chiropractic billing companies, free.
Documentation Requirements for CPT 98940
Documentation is what separates a clean 98940 claim from a denied one or an audit finding. Every CMT claim must be backed by a SOAP note that supports the medical necessity of the treatment, identifies the spinal regions treated, and shows measurable progress toward a treatment goal. Payers, especially Medicare, are increasingly using automated claim-review systems to flag documentation gaps, which means the days of vague chart notes surviving without scrutiny are over.
A compliant 98940 SOAP note should include the following elements. The subjective section documents the patient complaint, including location, severity, and any change since the last visit. The objective section records examination findings, including the specific spinal regions assessed, range of motion measurements, palpation findings, and any orthopedic or neurological test results that support subluxation. The assessment ties the findings to the diagnosis and states whether the patient is improving, stable, or worsening. The plan describes the treatment performed (naming the spinal regions adjusted), the response to treatment, and the plan for continued care including frequency and duration.
For Medicare specifically, the documentation must demonstrate that the treatment is active and corrective. This means showing measurable functional improvement visit over visit. If the notes show the same subjective complaints, the same objective findings, and the same treatment plan for weeks without change, the payer will reclassify the care as maintenance, which Medicare does not cover. Maintenance care is not a billing error in itself, but billing it to Medicare with an AT modifier is.
The biggest issue we see providers run into is documenting in templates that repeat the same language visit after visit. When every note reads identically, the payer concludes that the patient is not improving and the care is maintenance. The fix is not longer notes. It is notes that change meaningfully between visits, reflecting the actual clinical progression.
Common CPT 98940 Denials and How to Prevent Them
CMT denials follow a predictable pattern, and every one of them is preventable with the right pre-submission process. These are the denial reasons that surface most frequently across the chiropractic practices we work with.
- Missing AT modifier on Medicare claims. Medicare denies CMT claims automatically when the AT modifier is not appended. Fix: build the AT modifier into every Medicare CMT claim template so it is never omitted.
- Diagnosis code does not support subluxation. Medicare requires a subluxation diagnosis (M99.0x series) as the primary code on CMT claims. Filing with a symptom code such as M54.50 (low back pain) as the only diagnosis triggers a denial because it does not establish the subluxation that Medicare requires. Fix: always list the subluxation code as primary and the symptom code as secondary.
- Documentation does not support the number of regions billed. If the chart note does not name the specific spinal regions treated, the payer may downcode 98941 to 98940 or deny the claim entirely. Fix: document each region by name (cervical, thoracic, lumbar, sacral, pelvic) in the SOAP note.
- Treatment classified as maintenance care. When documentation shows no measurable improvement over consecutive visits, the payer reclassifies the care as maintenance, which Medicare does not cover. Fix: document functional progress at each visit and adjust the treatment plan when progress stalls.
- Billing CMT with non-covered services on a Medicare claim. Adding therapeutic modalities or exercises to a Medicare chiropractic claim results in denial of those line items and can delay processing of the CMT code. Fix: separate covered CMT services from non-covered services and use the appropriate modifiers or ABN (Advance Beneficiary Notice) when billing non-covered items.
- MPPR (Multiple Procedure Payment Reduction) not accounted for. When multiple therapy services are billed on the same date, the second and subsequent services are reduced by 50% on the practice expense component. This is not a denial but a payment reduction that catches practices off guard when they do not account for it in their expected reimbursement. Fix: understand the MPPR rules and set realistic collection expectations for multi-service visits.
Which ICD-10 Codes Support CPT 98940?
Every 98940 claim requires an ICD-10-CM diagnosis code that supports the medical necessity of chiropractic manipulative treatment. For Medicare, the primary diagnosis must be a subluxation code from the M99.0x series. For commercial payers, the primary diagnosis can be either a subluxation code or a symptom-based code depending on the payer contract, but subluxation documentation must still be present in the chart.
The most commonly paired ICD-10 codes with CPT 98940 include M99.01 (segmental and somatic dysfunction of cervical region), M99.02 (thoracic region), M99.03 (lumbar region), M99.04 (sacral region), and M99.05 (pelvic region). These codes identify the specific spinal region where the subluxation is documented and should match the regions treated. Secondary diagnosis codes such as M54.2 (cervicalgia), M54.50 through M54.59 (low back pain by laterality), M54.6 (pain in thoracic spine), and G89.29 (other chronic pain) can be added to support the clinical indication.
A coding detail worth confirming: M54.5 (low back pain) is a non-billable header code. It was subdivided into M54.50 (low back pain, unspecified), M54.51 (vertebrogenic low back pain), and M54.59 (other low back pain), and only those specific codes are valid on a claim. Practices still filing with M54.5 will receive automatic rejections. Verify your diagnosis code sets are current before submitting any claims.
In our experience matching providers with billing partners, the diagnosis code mismatch is one of the top three reasons for chiropractic claim denials. The most common error is listing the pain code as the primary diagnosis on a Medicare claim when the subluxation code should be primary. The second most common is using a non-specific M99.00 (segmental dysfunction, head region) when a more specific regional code such as M99.01 (cervical) is available and more appropriate.
Frequently Asked Questions
What is CPT code 98940?
CPT 98940 is the chiropractic manipulative treatment (CMT) code for spinal manipulation of one to two regions. It is the base-tier CMT code and is selected when the chiropractor adjusts one or two of the five recognized spinal regions: cervical, thoracic, lumbar, sacral, and pelvic.
What is the difference between CPT 98940, 98941, and 98942?
The codes are tiered by the number of spinal regions treated. CPT 98940 covers one to two regions, 98941 covers three to four regions, and 98942 covers all five regions. The reimbursement increases with each tier. The code selection is based on how many regions the documentation supports, not how many adjustments are performed.
Does Medicare cover CPT 98940?
Yes, but only for active corrective treatment of spinal subluxation. The AT modifier must be appended to every Medicare CMT claim. The primary diagnosis must be a subluxation code from the M99.0x series. Medicare does not cover maintenance care, extraspinal manipulation, or other chiropractic services such as therapeutic modalities.
What is the AT modifier in chiropractic billing?
The AT modifier indicates active treatment on Medicare chiropractic claims. It tells Medicare the patient has not reached maximum therapeutic benefit and measurable improvement is still expected. Without the AT modifier, Medicare denies the CMT claim automatically because it reads the service as maintenance care.
How much does Medicare pay for CPT 98940?
Medicare reimburses CPT 98940 at approximately $28 nationally before geographic adjustment, based on the 2026 non-QP conversion factor of $33.4009. The exact amount varies by locality because CMS applies Geographic Practice Cost Indices (GPCIs) that adjust for regional cost differences.
What documentation is required for CPT 98940?
A compliant SOAP note must identify the spinal regions treated by name, document the subluxation with objective findings (asymmetry, range of motion, tissue or tone changes), describe the patient complaint, and show measurable progress toward a treatment goal. For Medicare, the note must also support that the care is active and corrective, not maintenance.
Can CPT 98940 be billed with E/M codes?
It depends on the payer. Some commercial insurers allow a separate E/M code (such as 99213 or 99214) on the same date as CMT when the evaluation is separately identifiable and documented with modifier 25. Medicare generally does not cover chiropractic E/M services, so billing E/M alongside 98940 on a Medicare claim results in a denial of the E/M code.
What happens if I bill 98941 but only document two regions?
The payer will either downcode the claim to 98940 (paying the lower rate) or deny it for documentation insufficiency. Repeated upcoding from 98940 to 98941 without supporting documentation is also an audit trigger that can lead to recoupment and compliance review. Always match the code to the regions documented in the SOAP note.
Next Steps
- Need the full list of chiropractic billing codes? Our chiropractic CPT codes guide covers the complete CMT family, E/M codes, therapeutic modalities, and modifiers chiropractors use daily.
- Looking for a chiropractic billing partner? Read our guide on how to find the right chiropractic medical billing service for the criteria that matter most when evaluating partners.
- Ready to stop losing revenue on CMT billing errors? Get matched with vetted chiropractic billing companies that code manipulative treatment correctly and catch the denials before they age out.
Chiropractic manipulation is the core of your practice, and every coding error on a 98940 claim multiplies across your patient volume. Whether it is missing AT modifiers, weak subluxation documentation, or upcoding that your chart notes cannot defend, the right billing partner catches these before they become write-offs or audit findings. Chiropractor Billers has connected more than 2,000 providers across all 50 states, with over 15 years in medical billing and rates starting as low as 6%. Finding a match is 100% free for providers.
