Guide
Medicare chiropractic billing is small enough to learn completely and dangerous enough to punish guessing. This is the whole system: what is covered, the modifiers, the ABN, the maintenance boundary, and the documentation that survives review, with the actual CMS manual citations, written by a practicing DC whose office bills it daily.
One service: manual manipulation of the spine to correct a subluxation. In CPT terms, 98940, 98941, or 98942. That is the entire covered benefit, defined in the Medicare Benefit Policy Manual, Chapter 15, section 240. Everything else a chiropractic office does for a Medicare patient, the exam, X-rays, therapies, extraspinal manipulation, supplies, is statutorily excluded from payment when a chiropractor furnishes it. Not denied for bad paperwork; excluded, permanently, regardless of documentation.
Two practice consequences follow. First, excluded services are billable to the patient, and with proper notice the patient knows the price before the visit rather than after. Second, a Medicare remittance denying your exam line is not a problem to fix; it is the system working as designed, and rebilling it only ages your AR.
Coverage requires a subluxation, demonstrated either by X-ray or by physical examination under the PART framework: Pain, Asymmetry, Range of motion abnormality, and Tissue or tone changes, with at least two of the four documented, one of which must be asymmetry or range of motion. The claim's diagnoses must carry the subluxation, and the regions billed must correspond to the regions where it was found. A three region adjustment supported by one region of findings is how CO-11 diagnosis denials and worse are born.
Medicare pays for active treatment: care that is reasonably expected to improve the patient's condition or function. When further clinical improvement cannot reasonably be expected, care is maintenance, and Medicare does not cover it. The AT modifier on a CMT line is your attestation that the visit was active treatment. It is not a billing habit; it is a signed statement, and it is the exact line the OIG audits.
The HHS Office of Inspector General reported that chiropractic services carry the highest improper payment rate among Medicare Part B services, that past OIG work found 40 to 47 percent of paid chiropractic claims were for maintenance therapy, that $76 million in 2013 chiropractic payments were questionable, and that $21 million was paid on claims lacking a Medicare covered primary diagnosis. This is why the AT modifier and the maintenance boundary deserve a written office policy, not tribal knowledge.
The transition is the skill. When a patient plateaus, the honest sequence is: the maintenance conversation, an ABN signed before the next visit, the GA modifier replacing AT on the claim, and the patient paying your cash rate. The claim still goes to Medicare with GA, Medicare denies it as expected, and the denial cleanly transfers responsibility to the patient who agreed to it in advance.
Reviewers read for a treatment plan with measurable goals, subluxation findings per region billed, visit notes that evolve as the patient changes, re-exams at sensible intervals demonstrating the improvement AT attests to, and a defensible endpoint where active care concluded or converted to maintenance. The anti-pattern is the cloned note: identical findings and identical region counts for months, which reads as a template, and templates billed as active treatment are how the 40 to 47 percent statistic happened.
| Timely filing | One calendar year from the date of service (Claims Processing Manual, Chapter 1, section 70) |
| 98943 extraspinal | Excluded; billable to the patient with proper notice |
| X-rays | Not payable when a chiropractor orders or furnishes them, though a subluxation may be demonstrated by X-ray taken elsewhere |
| Therapies (97110, 97140, etc.) | Excluded from chiropractor payment; the patient responsibility path requires notice |
| Medicare Advantage | Plan rules vary; many mirror original Medicare's chiropractic limits, some add prior auth. Verify per plan |
Maintenance care warnings before signing, ABN capture built into the workflow with the GA modifier applied when one is on file, AT enforced on active care claims, re-exam gates, and a denial worklist that routes Medicare maintenance denials to the cash conversion path instead of a rebill loop. The guardrails exist because our own practice bills Medicare every day under these exact rules.
General information for billing teams, not legal or compliance advice for any individual claim. CMS manuals and your Medicare Administrative Contractor's policies control.