- Chiropractic billing centers on the chiropractic manipulative treatment (CMT) codes CPT 98940–98943, billed by the number of spinal regions treated.
- Medicare covers only manual manipulation of the spine to correct a subluxation — and only when it is active/corrective treatment, signaled by the AT modifier.
- Maintenance therapy is not covered by Medicare; billing it as active care (or omitting the AT modifier appropriately) is a top denial and audit trigger.
- Documentation must establish a subluxation, a treatment plan, and measurable functional improvement to support medical necessity.
What is chiropractic billing?
Chiropractic billing is the coding and claims workflow chiropractors use to get reimbursed for spinal manipulation and related services. The core of every chiropractic claim is the chiropractic manipulative treatment (CMT) family of CPT codes, which describe manual adjustment of the spine and, in one code, the extraspinal regions.
Because payer rules — especially Medicare's — are unusually narrow for chiropractic, clean claims depend on matching the right code to the regions treated, applying the correct modifier, and documenting medical necessity. For practices that would rather not manage this in-house, our chiropractic billing services handle it end to end.
The chiropractic CPT codes (98940–98943)
The four CMT codes are distinguished by how many spinal (and extraspinal) regions are manipulated in the session. The five spinal regions are cervical, thoracic, lumbar, sacral, and pelvic.
| CPT code | Description | Regions treated |
|---|---|---|
| 98940 | CMT, spinal | 1–2 regions |
| 98941 | CMT, spinal | 3–4 regions |
| 98942 | CMT, spinal | 5 regions |
| 98943 | CMT, extraspinal | 1+ extraspinal region (e.g., extremities, head, rib cage) |
Billing the higher-region code (e.g., 98942) without documentation supporting manipulation of all five regions is a frequent overcoding flag.
Medicare coverage rules for chiropractic
Medicare's chiropractic benefit is among the most restrictive in the program. Key rules:
- Medicare covers only manual manipulation of the spine to correct a subluxation — codes 98940, 98941, and 98942. The extraspinal code 98943 is statutorily non-covered by Medicare.
- Coverage applies only to active/corrective treatment, not maintenance. The AT (Active Treatment) modifier must be appended when the care is corrective.
- Services that chiropractors commonly perform but Medicare does not cover when furnished by a chiropractor include X-rays, exams, and therapy modalities — these are denied as outside the chiropractic benefit.
- A documented subluxation (by physical exam using the PART criteria, or by X-ray) is required to support the claim.
Key chiropractic modifiers
Modifiers tell Medicare and commercial payers how to interpret the CMT service. The most important:
| Modifier | When to use it |
|---|---|
| AT | Active/corrective treatment — required on covered CMT claims to Medicare. Omit it for maintenance care. |
| GA | A signed Advance Beneficiary Notice (ABN) is on file when a denial is expected (e.g., maintenance care). |
| GZ | A service expected to be denied but no ABN was obtained (not billable to patient). |
| GY | A statutorily non-covered service (e.g., 98943 to Medicare) — generates a denial for secondary payers. |
Documentation requirements
Every covered chiropractic visit must document medical necessity. Capture:
- The subluxation and the level(s) involved, identified by exam (PART: Pain/tenderness, Asymmetry, Range-of-motion change, Tissue/tone changes) or X-ray.
- The initial visit elements: history, the chief complaint, the mechanism of injury, and a treatment plan with measurable goals.
- The subsequent visit elements: progress, changes to the plan, and the patient's response.
- The regions treated, to justify the CMT code level (98940 vs. 98941 vs. 98942).
Top chiropractic billing denials and fixes
Most chiropractic denials are preventable. The numbered list below ranks the most common:
- Missing AT modifier on active care — Medicare denies as maintenance. Fix: append AT whenever care is corrective and documented.
- Billing maintenance as active treatment — audit and recoupment risk. Fix: collect an ABN and use GA when care becomes maintenance.
- CMT code level not supported — e.g., 98942 billed without five documented regions. Fix: code to the regions actually treated and documented.
- Non-covered services billed to Medicare — X-rays, exams, modalities by a chiropractor. Fix: use GY and bill the patient/secondary appropriately.
- Insufficient subluxation documentation. Fix: document PART findings or X-ray on every claim.
For deeper claim-quality strategy, see our guides to clean claims and denial management, plus how to track days in AR.
2026 reimbursement notes
CMT codes are paid under the Medicare Physician Fee Schedule and vary by locality, with 98941 (3–4 regions) typically the most-billed code. Because fee schedules and coverage policies update annually, confirm current-year values and your local MAC's policy before quoting reimbursement. Accurate region coding and disciplined AT-modifier use — not the per-visit rate — determine whether a chiropractic practice collects what it earns.
Frequently asked questions
The core chiropractic codes are the chiropractic manipulative treatment (CMT) codes: 98940 (1–2 spinal regions), 98941 (3–4 regions), 98942 (5 regions), and 98943 (extraspinal). The code is chosen by the number of regions manipulated and documented during the visit.
AT stands for Active Treatment. Medicare requires the AT modifier on covered chiropractic manipulation claims to indicate the care is active or corrective. Maintenance therapy is not covered and should not carry the AT modifier; misusing AT on maintenance visits is a common audit trigger.
Medicare covers only manual manipulation of the spine to correct a subluxation (CPT 98940–98942) when it is active, corrective treatment. It does not cover the extraspinal code 98943, maintenance therapy, or services like X-rays, exams, and therapy modalities when performed by a chiropractor.
Document the subluxation and levels involved (via PART exam criteria or X-ray), a treatment plan with measurable goals on the initial visit, progress and response on subsequent visits, and the regions treated to justify the CMT code level. This establishes medical necessity for payment.
The most common reasons are a missing AT modifier on active care, billing maintenance as active treatment, a CMT code level unsupported by documented regions, billing Medicare for non-covered services, and insufficient subluxation documentation. Most are preventable with correct coding and complete notes.