Chiropractic billing
The Benefit Policy Manual puts it in one sentence: the term physician under Part B includes a chiropractor who meets the qualifying requirements, but only for treatment by means of manual manipulation of the spine to correct a subluxation. Everything else the profession does sits outside the benefit -- including the x-ray taken to demonstrate the subluxation, which is covered when a medical doctor orders it and not when a chiropractor does.
- Coverage is limited to manual manipulation of the spine to correct a subluxation
- No other service furnished by, or ordered by, a chiropractor is covered
- The AT modifier signals active treatment; a claim without it is treated as maintenance and denied
- The precise level of the subluxation must be specified to substantiate the claim
This is an educational guide to how billing works for chiropractic — its workflow, coding, and payer considerations. It is general information, not a statement that US Medical Billing serves this specialty, and not billing, coding, or legal advice.
What makes chiropractic billing distinct
Every other practitioner type Medicare recognizes is recognized for a scope of practice. Chiropractic is recognized for a procedure. The Benefit Policy Manual states that the term physician under Part B includes a chiropractor who meets the specified qualifying requirements, but only for treatment by means of manual manipulation of the spine to correct a subluxation. Coverage of chiropractic service is specifically limited to treatment by means of manual manipulation -- that is, by use of the hands. Everything the profession does that is not that is outside the benefit, not merely reimbursed differently.
The consequence that surprises people most is about tests. The manual states that no other diagnostic or therapeutic service furnished by a chiropractor or under the chiropractor's order is covered, and spells it out: if a chiropractor orders, takes, or interprets an x-ray or any other diagnostic test, the test can be used for claims-processing purposes, but Medicare coverage and payment are not available for it. The same manual then confirms that an x-ray taken to demonstrate a subluxation is a covered diagnostic test if ordered, taken and interpreted by a physician who is a doctor of medicine or osteopathy. The film is identical. Who ordered it decides whether it is payable.
Hand-held manual devices are permitted -- those where the thrust of the force of the device is controlled manually -- but the manual adds that no additional payment is available for the use of the device, and Medicare does not recognize an extra charge for the device itself. Since claims with dates of service on or after 1 January 2000, an x-ray is not required to demonstrate the subluxation, though a chiropractor may still choose to use one. Where an x-ray is used it must have been taken reasonably proximate to the start of the course of treatment, which the manual treats as no more than twelve months before or three months after it begins, with an allowance for chronic subluxation such as scoliosis.
The active-treatment distinction is enforced through a modifier whose absence is itself a statement. A chiropractor must place the AT modifier on a claim when providing active or corrective treatment for acute or chronic subluxation. The manual then states that the AT modifier must not be placed on the claim when maintenance therapy has been provided, and that claims without the AT modifier will be considered as maintenance therapy and denied. There is no neutral claim: attaching the modifier asserts active treatment, and omitting it concedes maintenance. The manual also cautions that the presence of the modifier does not in all instances mean the service is reasonable and necessary, and contractors may deny after medical review.
What separates the two is prognosis rather than technique. A condition is acute where a new injury is being treated and manipulation is expected to improve the condition or arrest its progression; chronic where significant improvement is not expected but continued therapy can be expected to result in some functional improvement. Once the clinical status has remained stable without expectation of additional objective clinical improvement, further manipulative treatment is maintenance therapy and is not covered. Maintenance therapy is defined broadly -- services that seek to prevent disease, promote health, prolong and enhance quality of life, or maintain or prevent deterioration of a chronic condition -- and that definition covers a great deal of what patients most want.
How chiropractic billing flows
A short cycle with a narrow benefit, in which most of the risk sits in one modifier and one line of the record.
Confirming the practitioner is on the contractor's file
Contractors maintain a reference file of chiropractors eligible for payment as physicians and pay only those on it, informed by the state agency through the CMS regional office. Eligibility is a precondition rather than a claim attribute.
Common operational challenges
The difficulties come from a benefit narrower than the practice around it, and a modifier that means something either way.
A practice larger than its benefit
Most of what a chiropractic clinic offers is outside Medicare's chiropractic benefit entirely. Running a covered service and a substantial non-covered service line side by side is the ordinary state of affairs, not an exception to manage.
A judgement that changes over a course of care
The same patient, the same technique and the same complaint can be active treatment in week one and maintenance in week ten. The transition is clinical, gradual, and has an immediate billing consequence.
Silence that is not neutral
A claim without the AT modifier is not an incomplete claim awaiting clarification. It is read as a statement that maintenance therapy was provided, and denied on that basis.
A test whose coverage depends on its order
An x-ray ordered by the chiropractor can still be used for claims-processing purposes while being unpayable. Practices reasonably assume a usable film is a billable one, and it is not.
Documentation and coding considerations
The notes below describe coverage conditions and documentation requirements from the Medicare manuals; they do not reproduce any code descriptions.
What the benefit actually covers
42 CFR 410.21(b)(1) provides that Part B pays only for a chiropractor's manual manipulation of the spine to correct a subluxation where the subluxation has resulted in a neuromusculoskeletal condition for which manual manipulation is appropriate treatment. Hand-held manual devices whose thrust is controlled manually may be used, but no additional payment is available for the device and no extra charge for it is recognized.
The exclusion of everything else
42 CFR 410.21(b)(2) states that Part B does not pay for X-rays or other diagnostic or therapeutic services furnished or ordered by a chiropractor. The manual adds that such a test may still be used for claims-processing purposes, without coverage or payment being available for the test itself.
The AT modifier, in both directions
It must be placed on the claim when providing active or corrective treatment for acute or chronic subluxation, and must not be placed where maintenance therapy was provided. Claims without it are considered maintenance therapy and denied. Its presence does not in all instances establish that the service was reasonable and necessary.
The level has to be named
The precise level of the subluxation must be specified by the chiropractor to substantiate a claim for manipulation of the spine, designated in relation to the part of the spine in which it is identified.
Where an advance notice is involved
Chiropractors who give a beneficiary an advance beneficiary notice follow the Claims Processing Manual's instructions and include the corresponding liability modifier on the claim -- the GA modifier, or in rare instances GZ.
Denial and rejection risks
One of these is automatic, and the rest are decided in the clinical note rather than on the claim.
A missing AT modifier
Not an omission to be corrected on resubmission so much as an assertion. The manual states that claims without the AT modifier will be considered as maintenance therapy and denied.
Active treatment that has quietly become maintenance
Once clinical status is stable without expectation of further objective improvement, continued manipulation is maintenance. A record that repeats the same findings visit after visit describes exactly that.
An unspecified level of subluxation
Without the precise level, the claim is not substantiated in the way the manual requires, whatever the manipulation actually addressed.
A chiropractor-ordered test billed as covered
The exclusion reaches services under the chiropractor's order, not only services they perform. Submitting the x-ray as an ordinary diagnostic claim asks for payment the benefit does not provide.
More than one treatment billed in a day
The manual addresses the intensive-care pattern of multiple daily visits directly: room or ward fees are not covered, and reimbursement is limited to not more than one treatment per day.
Payer-process considerations
Review of these claims is built to work differently from review of other Part B claims.
Reasonableness is judged on chiropractic principles
The manual instructs that judgments about the reasonableness of chiropractic treatment must be based on the application of chiropractic principles, recognizing the differences between chiropractic and traditional medicine, and permits contractors to use chiropractic consultation in reviewing claims.
Eligibility is held on a list
Contractors establish a reference file of chiropractors eligible for payment as physicians and pay only those on file, with information furnished through the CMS regional office from the state agency.
Payment can go to the beneficiary
Payment is based on the physician fee schedule and made to the beneficiary or, on assignment, to the chiropractor -- so the assignment decision determines who receives the money as well as what is collected at the desk.
Commercial plans and Medicare Advantage vary
The narrow benefit described here is Original Medicare's. Commercial plans and Medicare Advantage plans often cover a broader range of chiropractic services, apply visit limits, and may require authorization -- so the same clinic runs two quite different rulebooks.
Revenue-cycle checkpoints
The first three are the ones that decide whether a Medicare claim can be paid at all.
- Record the precise level of the subluxation, and how it was demonstrated, at every visit
- Make the active-versus-maintenance decision explicitly, and record the reasoning that supports it
- Apply the AT modifier only for active or corrective treatment, and withhold it deliberately for maintenance
- Keep non-covered services -- examinations, therapies, supplies, tests -- on a separate financial footing agreed in advance
- Do not submit chiropractor-ordered diagnostic tests as covered claims, even where the film is used to support the manipulation
- Issue the advance notice before a maintenance visit, and carry the corresponding liability modifier on the claim
- Bill no more than one treatment per day, and keep room or ward charges off the claim entirely
- Confirm the practitioner is on the contractor's eligible file before relying on Medicare payment
Related & connected
Services, tools, background reading and definitions that connect to the chiropractic revenue-cycle steps above.
Related services
- Coding supportA benefit where one modifier carries the whole active-versus-maintenance decision.
- Patient billing & supportRunning the substantial non-covered side of a practice openly rather than by surprise.
- Denial managementSeparating a denial that was a coding decision from one that was a clinical trajectory.
Calculators & tools
From the Knowledge Base
- The Advance Beneficiary NoticeThe instrument that makes a maintenance visit a planned patient charge rather than a dispute.
- Non-covered service denialWhat it means for a service to be outside a benefit rather than short of documentation.
- Billing, rendering and referring provider identifiersWhy who ordered a test is a claim fact, and here a coverage fact too.
- Medicare Part B billingThe framework this unusually narrow benefit sits inside.
Glossary
- ModifierHere, a two-character code whose absence is read as a positive statement about the service.
- Advance Beneficiary NoticeThe written notice that shifts financial responsibility before an expected non-covered service.
- Covered serviceThe category this benefit defines by a single procedure rather than by a scope of practice.
- Referring providerThe role that, for a chiropractor-ordered test, decides whether the test is payable.
Frequently asked questions
What does Medicare actually cover in chiropractic?
One thing. The Benefit Policy Manual states that the term physician under Part B includes a chiropractor who meets the specified qualifying requirements, but only for treatment by means of manual manipulation of the spine to correct a subluxation, and that coverage of chiropractic service is specifically limited to treatment by means of manual manipulation -- by use of the hands. Hand-held manual devices whose thrust is controlled manually may be used in performing it, but no additional payment is available for the device and Medicare does not recognize an extra charge for the device itself.
Why is an x-ray covered for one practitioner and not another?
Because the exclusion attaches to the order, not to the test. The manual states that no other diagnostic or therapeutic service furnished by a chiropractor or under the chiropractor's order is covered, and that where a chiropractor orders, takes or interprets an x-ray or other diagnostic test, the test can be used for claims-processing purposes but Medicare coverage and payment are not available for it. The same manual confirms that an x-ray taken to determine or demonstrate a subluxation is a covered diagnostic test when ordered, taken and interpreted by a physician who is a doctor of medicine or osteopathy. Since 1 January 2000 an x-ray has not been required to demonstrate the subluxation at all.
What does the AT modifier do?
It separates active treatment from maintenance, and it does so in both directions. A chiropractor must place the AT modifier on a claim when providing active or corrective treatment to treat acute or chronic subluxation. The manual then states that the modifier must not be placed on the claim when maintenance therapy has been provided, and that claims without the AT modifier will be considered as maintenance therapy and denied. So there is no silent claim -- an omission is read as a statement. The manual also notes that the presence of the modifier may not in all instances indicate the service is reasonable and necessary, and that contractors may deny after medical review.
When does treatment become maintenance therapy?
When further clinical improvement cannot reasonably be expected from continuing care and the treatment becomes supportive rather than corrective. The manual describes an acute condition as a new injury where manipulation is expected to improve the condition or arrest its progression, and a chronic condition as one not expected to significantly improve or resolve but where continued therapy can be expected to produce some functional improvement. Once clinical status has remained stable for a condition without expectation of additional objective clinical improvement, further manipulative treatment is maintenance therapy and is not covered. Maintenance therapy is defined to include services seeking to prevent disease, promote health, prolong and enhance quality of life, or maintain or prevent deterioration of a chronic condition.
How much treatment does Medicare expect?
The manual sets expectations rather than a hard limit, and one explicit cap. It says a chiropractor should be afforded the opportunity to effect improvement, or arrest or retard deterioration, within a reasonable and generally predictable period; that acute subluxation problems may require as many as three months of treatment while some require very little, with treatment often frequent at first and decreasing as improvement is obtained; and that a chronic spinal joint condition may require a longer treatment time but not a higher frequency. It then addresses the intensive-care pattern of multiple daily visits directly: room or ward fees are not covered, and reimbursement is limited to not more than one treatment per day.
Sources
Last reviewed August 1, 2026.
- Centers for Medicare & Medicaid Services (CMS)Medicare Benefit Policy Manual (Pub. 100-02), Chapter 15 §240 and subsections -- the definition of physician limited to manual manipulation of the spine to correct a subluxation; the verification of chiropractor qualifications on a contractor reference file; the limitation of coverage to manual means and the treatment of hand-held manual devices; the exclusion of every other service furnished by or ordered by a chiropractor and the contrast with a test ordered by a doctor of medicine or osteopathy; the definition of subluxation and the x-ray proximity rules; the acute, chronic and maintenance distinctions; the mandatory AT modifier and the rule that claims without it are considered maintenance therapy and denied; the advance beneficiary notice modifiers; the requirement to specify the precise level of subluxation; and the treatment parameters including the one-treatment-per-day limit and the exclusion of room or ward fees
- Office of the Federal Register / eCFR42 CFR 410.21 Limitations on services of a chiropractor -- paragraph (b)(1), that Medicare Part B pays only for a chiropractor's manual manipulation of the spine to correct a subluxation where the subluxation has resulted in a neuromusculoskeletal condition for which manual manipulation is appropriate treatment; and paragraph (b)(2), that Part B does not pay for X-rays or other diagnostic or therapeutic services furnished or ordered by a chiropractor. Paragraph (a) sets the qualification requirements a chiropractor must meet
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