Chiropractic coverage: Medicare vs. Medicare Advantage vs. commercial payers.
Three payer categories, three different chiropractic coverage rules — and a claim built for one of them frequently fails against another. Traditional Medicare covers exactly one service and enforces it with a modifier. Medicare Advantage inherits that same limitation but polices it with prior authorization instead. Commercial payers usually cover far more, but cap it a different way entirely. This guide lays out the three side by side, with the MAC-by-MAC source documents to confirm your own jurisdiction's Medicare rule directly.
Key takeaways
- Only Medicare fee-for-service enforces coverage through a modifier. AT (active) versus GA (maintenance, with ABN) is a Medicare-specific mechanism — Medicare Advantage and commercial payers don't run on the same switch.
- Medicare Advantage can't cover less than Medicare, but it can review more. The manipulation-only limitation carries forward; utilization review and visit-count caps are layered on top of it, plan by plan.
- Commercial payers usually cover more than Medicare — extraspinal manipulation, modalities, sometimes exams — but almost every plan replaces the open-ended benefit with a hard annual visit cap instead.
- Medicare LCDs are written per MAC, not nationally. "The article says" means nothing without naming the contractor and the document ID — six are listed below.
Traditional Medicare: manipulation only, enforced by modifier
Medicare Part B's chiropractic benefit is a statutory exclusion, not a coverage judgment call: it covers manual manipulation of the spine to correct a demonstrated subluxation, and nothing else a chiropractor performs. No exams, no x-rays, no extraspinal manipulation (98943), no modalities — all of it is outside the benefit regardless of medical necessity. That structure is covered in full in our complete chiropractic billing guide; what matters here is how Medicare enforces the one thing it does cover.
The enforcement mechanism is the AT modifier, and it's binary. AT certifies the treatment is active/corrective — reasonably expected to result in improvement, or necessary to establish a diagnostic baseline early in a course of care. The moment documentation stops supporting that (no further expected improvement in PART findings or function), the claim has to switch to GA, which certifies a signed, service-specific Advance Beneficiary Notice is on file and the expected denial should post as patient responsibility rather than a payer dispute. There's no middle ground and no downcode: a 98940–98942 line missing AT denies outright as CO-4, not at a reduced rate.
- PART findings show a measurable deficit and the plan expects improvement.
- Treatment is early in the course of care, establishing a diagnostic baseline.
- The note documents a trajectory — pain scale, ROM, or function trending toward the treatment goal.
- The record shows a plateau — no further expected improvement in PART findings or function.
- Care has become maintenance: sustaining the current status, not correcting it further.
- A signed, service-specific ABN is on file dated before the visit it covers.
Two failure modes sit on either side of this line. Billing AT after the note stops supporting active treatment is upcoding — the exact pattern a RAC audit is built to find, because it's checkable line by line against the documented trajectory. Billing GA without a properly executed ABN doesn't protect the practice either: the claim can still deny with the practice unable to collect from the patient, because the modifier's patient-liability shift depends entirely on the ABN actually existing and being valid, not on the modifier alone.
Medicare Advantage: same limitation, different enforcement
Medicare Advantage plans cannot cover less than traditional Medicare covers for the same benefit category, so the manipulation-only, active-versus-maintenance limitation carries forward into every MA chiropractic benefit. What changes is how it's policed. Instead of relying primarily on the AT/GA modifier distinction claim by claim, MA plans administer coverage through their own utilization review process and, increasingly, prior authorization — a parallel gate that doesn't care whether the modifier on the claim is technically correct.
UnitedHealthcare's Medicare Advantage prior-authorization expansion is the clearest live example: chiropractic and outpatient therapy delivered in multidisciplinary offices and outpatient hospital settings now requires prior auth once a new plan of care exceeds 6 visits or 8 weeks, whichever comes first. A claim for visit 7 can be coded perfectly — correct CMT code, correct region count, correct AT modifier, complete PART documentation — and still deny if the extended plan of care wasn't submitted and cleared in advance. That's a workflow failure, not a coding failure, and it needs a workflow fix, not a coding fix. The full visit-count mechanics, the exemptions, and the standard MA annual visit-cap ranges by plan design are in our chiropractic prior authorization guide.
Beyond UHC's specific policy, MA plans broadly set their own annual chiropractic visit limits on top of the underlying Medicare coverage rule — commonly reported in the 20-to-30-visit range, though some plans authorize more, or effectively unlimited visits, when medical necessity is clearly documented throughout. This varies materially by carrier and even by product line within the same carrier. Verify the specific plan's visit cap and prior-auth trigger during eligibility and benefits verification, before the first visit, not after a claim denies mid-course.
Commercial payers: broader coverage, different caps
Commercial payers are the outlier in a useful direction: most cover CMT without importing Medicare's active-versus-maintenance distinction at all, and many cover extraspinal manipulation, exams, and some modalities that Medicare statutorily excludes. That's real, meaningful upside for a cash-and-commercial-mixed practice. But the tradeoff is structural, not incidental — nearly every commercial plan replaces Medicare's open-ended-but-modifier-gated benefit with a fixed annual visit count instead, and that cap applies regardless of whether the documentation would satisfy Medicare's active-treatment standard.
Modifier requirements diverge just as much. Commercial payers do not use Medicare's AT/GA/GY/GZ set as a rule, and assuming they do because the CPT codes are identical is a common, avoidable error. Where a commercial payer does require a modifier — distinguishing CMT from a same-day E/M, or unbundling 97140 from CMT under its own bundling logic — it's typically the standard 25 or 59/XS framework, not a chiropractic-specific set. The practical implication: don't build one modifier rule engine that applies AT/GA logic across the whole payer mix. Segment scrubber rules by payer category, not just by CPT code.
| Dimension | Traditional Medicare | Medicare Advantage | Commercial |
|---|---|---|---|
| What's covered | Manual spinal manipulation only — statutory exclusion of everything else | Same statutory floor as Medicare, administered at plan level | Usually broader — CMT plus extraspinal/modalities on many plans |
| Active vs. maintenance | Enforced via AT/GA on every claim line | Underlying rule applies; enforced via UR/prior auth more than modifier alone | Generally not imported as a distinct concept |
| Visit limits | No fixed cap — gated by documented medical necessity instead | Plan-set, commonly 20–30/year; some unlimited with documentation | Plan-set, varies by employer group and product |
| Prior authorization | Not required for CMT itself | Increasingly required past an initial visit window (see UHC policy above) | Payer- and plan-specific; verify per plan |
| Required modifiers | AT (active) or GA (maintenance, ABN on file); GY for excluded services; GZ signals no ABN | Same Medicare set for the covered benefit, plus plan-specific documentation for UR | Rarely AT/GA; standard 25 and 59/XS where applicable |
| Coverage source document | MAC-specific LCD/article — see table below | Plan's own coverage policy, layered on the Medicare floor | Plan certificate of coverage / provider manual |
Find your MAC's current chiropractic article
Medicare coverage documentation for chiropractic services is written and maintained per Medicare Administrative Contractor, not nationally, so "the LCD says" is only useful once you name the contractor. Six documents are active or recently retired as of this build, confirmed directly against the CMS Medicare Coverage Database.
| Document | Type | MAC | Effective date | Status |
|---|---|---|---|---|
A56273 | Article | WPS Insurance Corporation | 08/28/2025 | Active |
A56455 | Article | CGS Administrators | 01/29/2026 | Active |
L37254 | LCD (companion) | CGS Administrators | 01/29/2026 | Active |
A56616 | Article | Palmetto GBA | 12/19/2024 | Active |
L37387 | LCD (companion) | Palmetto GBA | 12/19/2024 | Active |
A57889 | Article | Wellpoint Federal | 04/01/2026 | Active — replaces Novitas & First Coast below |
A58345 | Article | Novitas Solutions | — | Retired 11/13/2025 |
A58412 | Article | First Coast Service Options | — | Retired 11/13/2025 |
Every active article uses the same core PART/AT framework, but covered-diagnosis specificity and update cadence differ by contractor, and an article can retire and route its jurisdiction to a different MAC entirely — exactly what happened when Novitas and First Coast both retired 11/13/2025 and their jurisdictions moved to Wellpoint Federal's new article, A57889. If your scrubber rules, order sets, or staff training materials still cite A58345 or A58412, you're working from a retired document; pull A57889 directly. Identify your practice's specific MAC first, then retrieve that MAC's current document by ID from the CMS Medicare Coverage Database rather than a cached copy or a search-engine snippet, since these get replaced without much notice.
Tag every patient's coverage category (traditional Medicare, MA carrier and plan, or commercial payer) at intake, and route the modifier and visit-cap logic off that tag rather than off the CPT code alone. A single "chiropractic billing rule" that assumes Medicare's AT/GA framework applies everywhere is the fastest way to misfile a commercial claim or miss an MA prior-auth trigger.
Not sure your payer mix is coded to the right coverage rules?
We'll map your chiropractic claims against the correct Medicare, Medicare Advantage, and commercial coverage logic for each payer, and show where the mismatch is costing you.
Frequently asked questions
Does Medicare Advantage have to follow Medicare's chiropractic coverage limits?
Yes for the underlying benefit — an MA plan cannot cover less than traditional Medicare covers, so the manipulation-only, active-versus-maintenance limitation carries forward. But MA plans administer that limitation through their own utilization review and prior-authorization processes rather than the AT/GA modifier framework alone, and most plans layer an annual visit cap on top, commonly in the 20-to-30-visit range depending on plan design. Confirm the specific plan's rules before treatment begins, not after a denial.
Do commercial payers require the AT modifier?
Rarely, and never assume they do just because the CPT codes match Medicare's. Most commercial payers cover CMT without importing Medicare's active-versus-maintenance distinction or its AT/GA/GY/GZ modifier set at all; they typically use their own visit caps and, where a modifier is required, their own payer-specific rules. Check the specific plan's provider manual or call for benefits before billing AT on a commercial claim on the assumption that it's universal — it isn't.
How do I find my MAC's current chiropractic coverage article?
Identify which Medicare Administrative Contractor holds your state's Part B jurisdiction, then pull that MAC's specific chiropractic billing and coding article by document ID from the CMS Medicare Coverage Database — not a cached PDF or a generic search result, since these get replaced. As of this build, active documents include WPS (A56273), CGS (A56455 and companion LCD L37254), Palmetto GBA (A56616 and companion LCD L37387), and Wellpoint Federal (A57889, which replaced Novitas's and First Coast's retired articles).
Verify before billing. CPT is a registered trademark of the American Medical Association; codes here are paraphrased, not reproduced from the CPT Professional edition. CPT, HCPCS and ICD-10 codes, coverage policy, and bundling edits change, including annual code-set updates. This page reflects standard industry practice and is provided for general education — it is not a substitute for your own compliance review, your current payer contracts, or the current-year code sets. Confirm requirements against your specific payer mix before submitting claims.