Chiropractic billing is built around a narrow but specific coding structure — spinal manipulation codes (98940-98942) selected by the number of regions treated, diagnosis codes that document subluxation or segmental dysfunction, and the AT modifier that Medicare requires for every active treatment claim.
The coding itself isn’t complex. The compliance requirements — especially for Medicare — are where most practices lose revenue through denials, downcoding, and audit exposure.
In this read, we’ll be exploring:
- CMT code selection by spinal region count
- The ICD-10 codes that support chiropractic claims
- Modifier logic for same-day E/M and manual therapy
- The five denial patterns that cost chiropractic practices the most
- Medicare’s narrow coverage rules and the AT modifier requirement
Which CPT codes do chiropractors bill?
Chiropractic procedure codes fall into two groups — CMT codes for spinal manipulation (selected by region count) and additional therapeutic/E/M codes that commercial payers may cover but Medicare generally doesn’t.
CMT codes
Code selection depends entirely on the number of spinal regions documented in the encounter note. CMS recognizes five spinal regions — cervical, thoracic, lumbar, sacral, and pelvic.
| CPT code | Spinal regions | Description |
| 98940 | 1-2 | CMT, spinal |
| 98941 | 3-4 | CMT, spinal |
| 98942 | 5 | CMT, spinal |
| 98943 | Extraspinal | CMT, extraspinal, 1 or more regions |
Only one CMT code from 98940-98942 is reported per encounter — these cannot be stacked. If the chiropractor adjusts cervical and lumbar, that’s two regions (98940). Cervical, thoracic, and lumbar is three regions (98941).
The region count must match the documentation. Billing 98942 when the note only describes two regions is upcoding — and it’s one of the most common audit findings in chiropractic billing.
Additional procedure codes
Commercial payers often cover therapeutic services that Medicare doesn’t cover under the chiropractic benefit.
| CPT code | Description | Medicare coverage |
| 97110 | Therapeutic exercises | Generally non-covered |
| 97140 | Manual therapy techniques | Generally non-covered |
| 97530 | Therapeutic activities | Generally non-covered |
| 97010 | Hot/cold pack application | Generally bundled, no separate payment |
| 99202-99215 | E/M office visits | Limited; modifier 25 required with CMT |
Which ICD-10 codes support chiropractic claims?
The M99.0x subluxation codes are the primary diagnosis family for chiropractic claims under CMS guidance, supported by musculoskeletal pain codes that document the clinical condition being treated.
Subluxation codes
The M99.0x family documents the subluxation that Medicare requires as a covered diagnosis.
| ICD-10-CM | Description |
| M99.01 | Segmental/somatic dysfunction, cervical |
| M99.02 | Segmental/somatic dysfunction, thoracic |
| M99.03 | Segmental/somatic dysfunction, lumbar |
| M99.04 | Segmental/somatic dysfunction, sacral |
| M99.05 | Segmental/somatic dysfunction, pelvic |
Common musculoskeletal codes
| ICD-10-CM | Description |
| M54.2 | Cervicalgia (neck pain) |
| M54.51 | Vertebrogenic low back pain |
| M54.6 | Pain in thoracic spine |
| M54.41 | Sciatica with lumbago, right side |
| M47.812 | Spondylosis without myelopathy, cervical |
| M47.816 | Spondylosis without myelopathy, lumbar |
Diagnosis specificity directly affects claim acceptance. Using M54.50 (unspecified low back pain) when findings support M54.51 (vertebrogenic) weakens the medical necessity argument. Payers increasingly reject unspecified codes when specific alternatives exist.
Quick Reference
Chiropractic Billing Cheat Sheet
What does Medicare actually cover for chiropractic?
Medicare’s chiropractic benefit is the most restrictive of any major payer. Getting this wrong is the number-one revenue problem for chiropractic practices with Medicare patients.
Covered services
Medicare covers only manual manipulation of the spine to correct a documented subluxation. The treatment must be active/corrective — meaning the goal is clinical improvement, not maintenance.
Non-covered services
The non-covered services include:
- Massage therapy
- Nutritional counseling and wellness adjustments
- X-rays ordered solely by the chiropractor in most circumstances
- Maintenance therapy (treatment to maintain function, not improve it)
- Physical therapy modalities when performed solely by chiropractors (97110, 97140)
The AT modifier
The AT modifier (Active Treatment) is required on every Medicare CMT claim. Claims without AT are processed as maintenance therapy and denied. Building AT into billing system defaults for Medicare patients prevents the single most common chiropractic denial.
ABN requirements
When a chiropractor expects Medicare won’t cover a service (maintenance care, non-covered modalities), an Advance Beneficiary Notice must be provided before treatment. Modifier GA (ABN on file) or GX (voluntary ABN) is appended to indicate the notice was issued.
Which modifier rules apply to chiropractic?
Chiropractic modifier errors cluster around two areas — the AT modifier on Medicare claims and modifier 59 on manual therapy billed alongside CMT. Both are frequently audited.
| Modifier | When to use it |
| AT | Every Medicare CMT claim (98940-98942) |
| 25 | E/M billed same day as CMT — must document a separately identifiable service |
| 59 / XS | Manual therapy (97140) billed with CMT at a different anatomical site |
| GA | Non-covered service where patient accepted financial responsibility via ABN |
| GY | Service Medicare never covers by law |
Modifier 59 on manual therapy alongside CMT is one of the most frequently audited chiropractic patterns.
The modifier is appropriate only when the manual therapy targets a different anatomical area and the documentation supports a distinct service.
Routine modifier 59 on every 97140 claim without supporting documentation creates audit exposure.
What documentation prevents chiropractic denials?
Every chiropractic encounter note must support both the clinical treatment and the billing code. When the note doesn’t match the code, the claim is denied or flagged for audit.
Initial visit
The first encounter must establish the clinical foundation.
- Functional limitations
- Chief complaint and history of present illness
- Examination findings (neurological and orthopedic tests)
- Subluxation identification with diagnosis (M99.01-M99.05)
- Treatment plan with goals and expected duration
- Spinal regions treated
Subsequent visits
Each follow-up must demonstrate active treatment progress.
- Regions adjusted
- Patient response to prior treatment
- Functional improvement or lack thereof
- Objective findings (ROM, palpation, orthopedic tests)
For Medicare, the documentation must show the patient is improving or that improvement is expected.
When improvement plateaus, treatment transitions to maintenance — and Medicare coverage ends. Continuing to bill Medicare after the plateau is a compliance violation that auditors specifically look for.
How do Medicare and commercial rules differ?
Medicare’s chiropractic benefit is far more restrictive than commercial coverage — different covered services, different modifier requirements, and different denial triggers. Practices must separate the two at the point of service, not at billing.
| Rule | Medicare | Commercial payers |
| CMT covered | Yes (subluxation only) | Yes (varies by plan) |
| Therapeutic exercises (97110) | Generally non-covered | Often covered |
| Manual therapy (97140) | Generally non-covered | Often covered |
| AT modifier required | Yes, every CMT claim | Usually not required |
| Maintenance therapy covered | No | Varies by plan |
A chiropractic billing workflow must separate Medicare patients from commercial patients at the point of service — not at the point of billing. The codes, modifiers, and covered services differ so substantially that using the same template for both guarantees denials on one or the other.
Denial Prevention
Top 5 Chiropractic Claim Denials
Your adjustments shouldn’t lose money at the billing desk
Most chiropractic denials trace back to the same handful of errors — missing AT modifiers, region-count mismatches, and maintenance therapy billed to Medicare.
MedHeave builds chiropractic billing controls directly into the claim workflow — AT modifier compliance, region-count validation against documentation, Medicare vs. commercial payer separation, and ABN tracking.
- Dedicated account managers with direct access
- Claims submitted within 24-48 hours of signed encounter notes
- Performance-based pricing (4-7% of collections) with no lock-in
- Denials addressed within 72 hours with payer-specific documentation
Contact us to see how structured chiropractic billing eliminates the denials your practice keeps repeating.
Frequently asked questions
Here are some commonly asked questions on this topic:
The primary chiropractic codes are 98940 (CMT, 1-2 spinal regions), 98941 (CMT, 3-4 regions), and 98942 (CMT, 5 regions). Code selection depends on the number of documented spinal regions treated — only one CMT code is reported per encounter. Additional codes include 98943 (extraspinal manipulation), 97110 (therapeutic exercises), 97140 (manual therapy), and E/M codes 99202-99215 for office visits billed with modifier 25 when performed same-day as CMT.
The primary diagnosis codes are M99.01-M99.05 (segmental and somatic dysfunction by spinal region), which document the subluxation that Medicare requires for coverage. Common supporting musculoskeletal codes include M54.2 (cervicalgia), M54.51 (vertebrogenic low back pain), M54.6 (thoracic spine pain), M47.x (spondylosis), and M54.41 (sciatica). Payers increasingly reject unspecified codes when more specific alternatives exist — always use the most specific code the clinical findings support.
Medicare covers only manual spinal manipulation to correct a documented subluxation, and only when the treatment is active/corrective rather than maintenance. The AT modifier is required on every CMT claim. Medicare generally does not cover therapeutic exercises, manual therapy modalities, massage, nutritional counseling, wellness adjustments, or X-rays ordered solely by the chiropractor. Non-covered services require an Advance Beneficiary Notice (ABN) before treatment, with modifier GA or GX appended to the claim.
The AT modifier indicates active/corrective treatment for subluxation. CMS requires it on every Medicare CMT claim (98940-AT, 98941-AT, 98942-AT). Claims submitted without AT are processed as maintenance therapy and automatically denied — making this the single most common Medicare denial in chiropractic billing. Building the AT modifier into billing system defaults for Medicare patients prevents the error entirely without relying on manual entry.
Active treatment aims to correct a condition and produce measurable clinical improvement. Maintenance therapy aims to maintain function or prevent deterioration after maximum therapeutic benefit is reached. Medicare covers active treatment but not maintenance. The difference must be documented in each encounter note — if improvement has plateaued and no further functional gains are expected, Medicare coverage ends. The chiropractor should issue an ABN and transition the patient to self-pay for continued care.
Yes, when the E/M service represents a significant, separately identifiable clinical encounter beyond the adjustment itself. Modifier 25 must be appended to the E/M code. The documentation must support a distinct clinical service — a separate problem evaluated, a new complaint assessed, or a significant re-evaluation conducted. Billing a routine adjustment visit as both CMT and E/M without separate documentation is a common audit trigger that CMS specifically reviews.
