Chiropractic Medical Billing Company: Medicare Rules, Modifier Traps, and What Your Billing Partner Must Get Right

By Medtransic | February 14, 2026 | 15 min read | Updated: February 15, 2026

Quick Summary: Chiropractic billing is one of the most denial-prone specialties in medicine. Medicare only covers spinal manipulation for subluxation, the AT modifier is required on every CMT claim, and improper modifier use causes 31% of chiropractic claim denials. Here's what makes chiro billing different and how to choose a billing company that actually knows the rules.

If you run a chiropractic practice and your billing feels like a constant battle with insurance companies, it's not your imagination. Chiropractic is one of the most heavily scrutinized and denial-prone specialties in all of healthcare. Medicare covers almost nothing you do — only spinal manipulation for documented subluxation, and only when it qualifies as active treatment. Every other service you provide to a Medicare patient is non-covered by default.

On top of that, one missing modifier can turn a payable claim into an automatic denial. Improper modifier use alone accounts for 31% of chiropractic claim denials. And the line between "active treatment" and "maintenance care" — a distinction that determines whether Medicare pays or doesn't — is one of the most audited gray areas in medical billing.

This is why hiring a general medical billing company to handle your chiropractic claims is a recipe for lost revenue. Chiropractic billing has rules that don't exist anywhere else in medicine, and the margin for error is razor-thin. This guide breaks down exactly what makes chiropractic billing different, where practices lose the most money, and what to demand from any billing company that wants to handle your claims.

Why Chiropractic Billing Is One of the Most Denial-Prone Specialties

Most medical specialties operate under a relatively straightforward billing model: you perform a service, you code it, you submit the claim, and — assuming the coding is correct and the patient has coverage — you get paid. Chiropractic doesn't work that way.

The core problem is that Medicare, the largest payer for many practices, has drawn an extremely narrow coverage box around chiropractic services. Medicare will only pay for manual manipulation of the spine to correct a vertebral subluxation. That's it. Not extraspinal adjustments. Not X-rays. Not massage therapy. Not therapeutic exercises. Not evaluations or re-evaluations. None of the ancillary services — including the rehabilitative care that physical therapy billing handles under its own set of rules — that make up a significant portion of what chiropractors actually do in a typical patient encounter.

Every claim that falls outside that narrow box has to be handled differently — billed with specific non-covered modifiers, supported by an Advance Beneficiary Notice (ABN), or directed to the patient for payment. A billing team that doesn't understand these boundaries will either submit claims that get denied, fail to collect from patients for non-covered services, or — worst case — bill Medicare for services it doesn't cover, which creates audit and compliance exposure.

Commercial payers add another layer of complexity. Unlike Medicare, many commercial plans do cover services beyond spinal manipulation — but their coverage rules, visit limits, pre-authorization requirements, and modifier preferences vary wildly, much like the payer-specific challenges seen in pain management billing. A billing company handling chiropractic claims has to navigate Medicare's strict limitations AND each commercial payer's unique rulebook simultaneously.

Then there's the multi-payer reality unique to chiropractic: a significant portion of chiropractic patients come through auto accident (personal injury), workers' compensation, or attorneys' liens — each of which has its own billing procedures, fee schedules, and payment timelines that bear no resemblance to standard insurance billing. If your billing company can't handle PI and workers' comp alongside commercial and Medicare claims, they can't fully manage a chiropractic practice's revenue cycle.

Medicare Chiropractic Rules: What's Covered, What's Not, and Why It Matters

Understanding Medicare's chiropractic coverage rules is non-negotiable for any billing company that handles chiro claims. These rules are strict, specific, and heavily audited.

What Medicare Covers

Medicare Part B covers chiropractic manipulative treatment (CMT) — and only CMT — when it is performed to correct a vertebral subluxation. The subluxation must be documented by X-ray taken within 12 months prior to or 3 months after the start of treatment, or by a physical examination that includes at least two of the four P-A-R-T components.

The P-A-R-T exam is a documentation framework specific to chiropractic Medicare billing. It stands for Pain/tenderness, Asymmetry/misalignment, Range of motion abnormality, and Tissue/tone changes. At least two of these four findings must be documented, and at least one of the two must be either Asymmetry or Range of motion. Without this documentation, the subluxation is not considered established for Medicare purposes, and the claim will be denied.

What Medicare Does NOT Cover

This is the list that trips up every general billing company that tries to handle chiropractic claims. When provided by a chiropractor, Medicare does not cover:

• X-rays and diagnostic imaging (even if used to document the subluxation)
• Evaluations and re-evaluations (E/M codes 99202–99215)
• Extraspinal manipulation (CPT 98943)
• Therapeutic exercises, manual therapy, neuromuscular re-education (97110, 97140, 97112)
• Modalities — electrical stimulation, ultrasound, hot/cold packs
• Massage therapy (97124)
• Acupuncture, nutritional counseling, and other ancillary services

Every one of these services must be billed with a GY modifier (indicating it is a statutory exclusion from Medicare coverage) or handled through an ABN process where the patient agrees to pay. A billing company that submits these services to Medicare without the proper modifier is creating a compliance problem — and when those claims get paid by mistake, the money will be recouped with interest on audit.

The Three CMT Codes Medicare Recognizes

Selecting the correct CMT code depends on how many spinal regions were treated and documented. Billing a 98941 when the documentation only supports two regions is upcoding. Billing a 98940 when four regions were treated and documented is leaving money behind. Your billing team needs to verify the code against the clinical note before every submission.

The AT Modifier: The Single Most Important Rule in Chiropractic Billing

The AT (Active Treatment) modifier is required on every Medicare claim for spinal manipulation — CPT codes 98940, 98941, and 98942. Without it, Medicare will automatically deny the claim as not medically necessary. No exceptions. No workaround.

The AT modifier tells Medicare that the manipulation being billed is active, corrective treatment for an acute or chronic subluxation — not maintenance care. It's a simple two-character modifier, but its absence is one of the single most common reasons chiropractic Medicare claims are denied.

Your billing company needs to understand not just that the AT modifier is required, but when it's appropriate and when it's not. That distinction requires reviewing the treatment notes — not just the superbill — to verify the patient is still in an active treatment phase with documented functional improvement.

Active Treatment vs. Maintenance Care: Where 64% of Overpayments Happen

The active vs. maintenance distinction is the highest-risk area in chiropractic billing. Medicare defines active treatment as care where there is a reasonable expectation of functional improvement — the patient is getting measurably better. Maintenance care is treatment designed to prevent regression or maintain the patient's current status. Medicare covers the former. It does not cover the latter.

The challenge is that the line between active and maintenance care isn't always obvious in practice. A patient with chronic back pain may show improvement over 8 visits, plateau for 4 visits, then improve again. At what point does active care become maintenance? The answer depends on the documentation — and that's exactly what Medicare auditors look at.

The 12-Visit Re-Evaluation Rule

Medicare requires a clinical reassessment at least every 12 visits or every 30 days, whichever comes first. This re-evaluation must document measurable progress — CMS guidance suggests at least 15% improvement in objective findings — and include revised treatment goals. Without this documented reassessment, claims beyond the 12th visit face an extremely high denial risk. CMS data indicates 78% of visits denied beyond 12 visits for insufficient documentation of ongoing medical necessity.

A specialized chiropractic billing company tracks each patient's visit count and flags the 12-visit threshold before it's crossed — giving you time to perform the re-evaluation and document the progress that supports continued billing with the AT modifier. A general billing company doesn't track this because it's a rule that doesn't exist in other specialties.

When to Transition to ABN Billing

When a patient has reached maximum therapeutic benefit and care transitions to maintenance, the practice should stop billing Medicare with the AT modifier. Instead, the patient should sign an Advance Beneficiary Notice (ABN) acknowledging that continued care is not covered by Medicare and that they accept financial responsibility. The claim is then submitted with the GA modifier (indicating an ABN is on file) so the patient can use the denial for secondary insurance purposes if applicable.

Failing to make this transition — continuing to bill with the AT modifier after the patient has plateaued — is the primary cause of chiropractic Medicare audits and recoupment actions. A billing company that doesn't monitor treatment progression and prompt you to make this switch is putting your practice at risk.

Modifier Pitfalls That Cause 31% of Chiropractic Claim Denials

Beyond the AT modifier, chiropractic billing requires a set of modifiers that don't apply to most other specialties. Using them incorrectly — or forgetting them entirely — is responsible for nearly a third of all chiropractic claim denials.

The CCI (Correct Coding Initiative) edits are particularly aggressive with chiropractic claims. Medicare's bundling rules require that manual therapy (97140), massage (97124), and neuromuscular re-education (97112) must be performed on a separate anatomic region from the CMT — and modifier 59 or XS must be appended to prove it. If the documentation doesn't support a distinct anatomic site, the modifier shouldn't be used — and if it's used without support, it triggers fraud flags.

A specialized chiropractic billing company knows every one of these modifiers, when each is required, and — critically — when each should NOT be used. A general billing company will either miss modifiers that should be there or apply them incorrectly, both of which cost you money or create compliance exposure.

The Top 5 Chiropractic Billing Denials and How to Prevent Them

1. Missing or incorrect AT modifier (31% of denials): This is the most common denial in chiropractic billing. Every Medicare CMT claim needs the AT modifier. Your billing company should verify its presence on every claim before submission — and verify that the documentation supports active treatment status.
2. Insufficient subluxation documentation (19% of denials): The subluxation must be the primary diagnosis (M99.xx codes), supported by either imaging or a P-A-R-T exam with at least two findings including Asymmetry or Range of motion. If the documentation is thin, the claim gets denied.
3. Wrong primary diagnosis (17% of denials): The subluxation code (M99.xx) must be listed as the primary diagnosis on every CMT claim. Listing a symptom code like back pain (M54.5) as primary — even if it's the patient's chief complaint — will result in a denial. The subluxation is the condition Medicare covers; the symptom is secondary.
4. Timely filing violations (9% of denials): Medicare requires claims to be submitted within 12 months of the date of service. While that sounds like plenty of time, practices with billing backlogs or companies transitioning between billing providers often miss this deadline. The fix is simple: submit within 30 days of service as standard practice.
5. No re-evaluation documentation beyond 12 visits: As discussed above, Medicare expects documented reassessment with measurable progress at least every 12 visits. Claims submitted after the 12th visit without a re-evaluation note face a 78% denial rate. Your billing company should track visit counts by patient and flag this threshold proactively.

What a Chiropractic Billing Company Should Actually Handle

A comprehensive chiropractic billing service covers the entire revenue cycle — not just claim submission. Here's what the scope should include:

• Insurance verification and benefits check: Confirming coverage, visit limits, pre-authorization requirements, and whether the patient's plan covers services beyond spinal manipulation before the visit.
• Coding review and modifier assignment: Verifying that CMT codes match the regions documented, AT modifiers are applied appropriately, GY modifiers are on all non-covered Medicare services, and CCI edits won't bundle services incorrectly.
• Claim submission within 24–48 hours: Clean claims submitted quickly with all required modifiers and documentation attached.
• Payment posting and EOB reconciliation: Posting payments, comparing amounts against contracted rates, and flagging underpayments for follow-up.
• Denial management and appeals: Identifying the root cause of every denial, correcting errors, resubmitting within payer deadlines, and formally appealing when appropriate.
• 12-visit threshold tracking: Monitoring each patient's visit count against the re-evaluation requirement and alerting you before the deadline.
• ABN management: Prompting you when a patient is approaching maintenance care status so you can obtain a signed ABN before the transition.
• Workers' comp and personal injury billing: Handling auto accident, workers' comp, and attorney lien claims with the correct fee schedules, forms, and follow-up cadences unique to each payer type.
• Patient billing and collections: Generating statements for patient responsibility balances, managing payment inquiries, and coordinating payment plans when needed.
• Reporting and analytics: Regular reports on clean claim rate, denial rate by reason code, average days in AR, collection ratio, and payer-specific performance.
• Credentialing and payer enrollment: Managing Medicare and commercial payer enrollment, keeping credentials current, and handling re-credentialing.

How to Choose a Chiropractic Medical Billing Company

The chiropractic billing market includes dozens of companies that list "chiropractic" on their website without the depth to back it up. Here's how to test whether a billing company actually knows chiropractic billing — or just claims to.

Ask them to explain the AT modifier and when it should NOT be used. This is the fastest litmus test. If they can't clearly articulate that the AT modifier is required on every Medicare CMT claim, that it certifies active treatment status, and that using it on maintenance care creates audit exposure — they don't know chiropractic billing well enough to handle your claims.

Ask how they track the 12-visit re-evaluation threshold. You want a system-level answer: do they track each patient's visit count and alert you before the 12th visit? Do they flag claims that go out after the 12th visit without a corresponding re-evaluation note? If this isn't built into their workflow, you'll accumulate denials.

Ask about their experience with workers' comp and personal injury billing. A significant portion of chiropractic revenue comes from auto accidents and work injuries. These cases involve different forms, fee schedules, authorization processes, and payment timelines than standard insurance. If a billing company can only handle commercial and Medicare claims, they're leaving a major revenue stream unmanaged.

Ask for their chiropractic-specific denial rate. A blended denial rate across all specialties is meaningless. You need to know how their chiropractic clients are performing. A competent chiro billing operation keeps denial rates under 5%.

Ask about software compatibility. Chiropractic practices use specialized EHR and practice management systems — ChiroTouch, ECLIPSE, Genesis, ChiroFusion, Jane, Platinum, and others. Your billing company needs to either integrate with your system or have an efficient data import process. A mismatch creates manual work and errors.

Ask about contract terms. Month-to-month with 30-day notice is the standard for companies that retain clients through results. Long-term contracts with termination penalties suggest they rely on the lock-in, not their performance.

How Much Does Outsourcing Chiropractic Billing Cost?

Chiropractic billing companies typically use one of three pricing models. Here's what to expect and what to watch out for with each.

Regardless of pricing model, the cost of outsourcing is typically offset by improved collection rates, fewer denials, faster reimbursement, and recovered revenue from claims that were previously written off. Most chiropractic practices that move from in-house or general billing to a specialized chiropractic billing partner see a 15% to 30% increase in collections within the first 90 days.

What Results Should You Expect?

A competent chiropractic billing company should deliver measurable results within 60 to 90 days. Here are the benchmarks to hold them to.

• >95% Clean Claim Rate - First-pass acceptance
• <5% Denial Rate - Industry-leading
• <30 days Average Days in AR - Fast turnaround
• >96% Net Collection Ratio - Maximum revenue

Clean claim rate above 95% means claims are submitted with correct CMT codes, appropriate modifiers, proper diagnosis sequencing (subluxation primary), and all required documentation on the first pass.

Denial rate below 5% confirms the team is applying the AT modifier correctly, managing the active vs. maintenance distinction, and catching documentation gaps before submission.

Average days in AR under 30 indicates the billing team is submitting claims quickly, following up on unpaid claims on a structured cadence, and resolving denials within payer appeal deadlines. ACOM Health, one of the better-known chiropractic billing companies, advertises an average of 16 days from date of service to payment — which is an excellent benchmark for insurance collections.

Net collection ratio above 96% means that after contractual adjustments, you're collecting at least 96 cents of every dollar you're owed. Top-performing chiropractic billing operations push this above 98%.

A 15% to 30% increase in collections is typical when a chiropractic practice transitions from general billing to a specialized partner. This comes from fewer denials, recovered underpayments, proper modifier use, improved coding accuracy, and faster claim turnaround.