Understanding the Impact of Claim Denials on Practice Revenue: A Comprehensive Analysis

Why Do Chiropractic Claims Get Denied?

If you’re running an independent chiropractic practice, you already know the answer to a question every practice manager asks: why do chiropractic claims get denied? The answer is not random. Chiropractic claims get denied for three root causes that appear again and again in your A/R aging report. The first is documentation that fails to establish medical necessity. The second is the maintenance versus active care distinction that payers use to reclassify covered treatment as non-covered. The third is coding errors tied to spinal region counts and modifier application. Each of these denial patterns is preventable. Understanding why chiropractic claims get denied—and what specific documentation or coding gap triggered each one—is the only path to stopping the cycle.

The Financial Reality Chiropractic Practices Are Living With

Across the U.S. healthcare system, initial claim denial rates reached 11.81% of claim value in 2024, up from 10.15% in 2020, According to benchmarking data from Kodiak Solutions reported by the Healthcare Financial Management Association.. Medical necessity denials specifically increased year over year in 2024. Chiropractic practices, which operate at the intersection of Medicare scrutiny and commercial payer tightening, carry denial risk that most specialty billing guides fail to explain with the precision the specialty demands.

The Office of Inspector General (OIG) has documented that chiropractic services have historically carried the highest improper payment rate in Medicare fee-for-service, ranging from 43.9% to 54.1% between 2010 and 2015, with overpayments primarily driven by billing active treatment codes for what Medicare classifies as maintenance care. That pattern has drawn sustained audit pressure on chiropractic practices, and the documentation bar has not gotten lower.

What that means for an independent chiropractic practice is straightforward. The difference between a practice that collects consistently and one that watches its accounts receivable age past ninety days is almost never clinical quality. It is documentation precision, modifier discipline, and payer intelligence applied before the claim leaves the practice.

The Seven Reasons Why Chiropractic Claims Get Denied

1. Medical Necessity Denials: Why Claims Get Denied Most Often

Medical necessity denials are the single largest revenue threat in chiropractic billing. They occur when the documentation on file fails to establish a direct, specific link between the patient’s diagnosis, the clinical findings at that visit, and the treatment being billed.

For Medicare, the standard is codified. Under CMS LCD L37387 and the Medicare Benefit Policy Manual Chapter 15 Section 240, chiropractic coverage is restricted to the treatment of subluxation of the spine by means of manual manipulation. The subluxation must be documented either by x-ray or by physical examination using the PART system. PART stands for Pain and tenderness, Asymmetry or misalignment, Range of motion abnormality, and Tissue tone changes. CMS requires that at least two of the four PART components be documented, and that at least one of those two falls under asymmetry or range of motion. Documenting only “patient reports pain” without an objective finding does not satisfy the standard. CMS’s own billing article states explicitly that a statement of “pain” alone is insufficient to substantiate a claim for spinal manipulation.

The PART system is not optional. It is the evidentiary framework Medicare uses to determine whether subluxation existed at the time of treatment. When PART documentation is absent or vague, there is no subluxation on record. Without subluxation on record, there is no covered service.

Commercial payers, including UnitedHealthcare and Aetna, have been tightening their own medical necessity criteria for chiropractic, particularly for higher-level CMT codes. Documentation that would pass a cursory review two years ago is increasingly triggering automated flags and medical review requests.

What audit-ready medical necessity documentation requires at every visit:

The primary diagnosis must be a spinal subluxation coded from the M99 family, such as M99.01 for cervical, M99.02 for thoracic, M99.03 for lumbar, or M99.04 for sacral. The subluxation must be documented with at least two PART elements, one of which is asymmetry or range of motion. Specific vertebral levels must be named, not just regions. Writing “cervical” does not meet the standard. Writing “C5” does. Secondary diagnoses supporting the neuromusculoskeletal condition, such as M54.2 for cervicalgia or M54.5 for low back pain, should be included and must align with the primary subluxation finding.

On each subsequent visit, CMS requires documentation of a review of the chief complaint and any changes since the last visit, a physical examination of the spine region involved, the provider’s assessment of any change in the patient’s condition, and an evaluation of how effective the treatment has been. Treatment notes that read as templated repetitions of the initial visit without any functional change documentation are a consistent audit trigger.

2. Why Claims Get Denied: Active Treatment Versus Maintenance Care

This is where Medicare exerts its most consequential leverage over chiropractic practices, and it is where the most financially damaging denials and recoupments originate.

Medicare covers chiropractic manipulation exclusively for active or corrective treatment. The Medicare Benefit Policy Manual defines active treatment as care where the manipulation is expected to result in improvement in or arrest of progression of the patient’s condition. When the clinical status has remained stable, without expectation of additional objective clinical improvement, CMS defines further treatment as maintenance therapy. Maintenance therapy is not covered under Medicare. It has never been covered.

Excerpt: A claim submitted without the AT modifier is treated by Medicare as maintenance care by default and denied. There is no appeal pathway for that specific failure.

The mechanism that separates these two categories at the claim level is the AT modifier. CMS requires that the AT modifier be appended to every chiropractic manipulation code, meaning 98940, 98941, and 98942, when billing Medicare for active treatment. A claim submitted for these codes without the AT modifier is treated by Medicare as maintenance care by default and denied. There is no appeal pathway for that specific failure because the modifier’s absence is read as the provider’s own attestation that the service is not active treatment.

The inverse failure is equally serious. Using the AT modifier when the clinical record does not support active treatment status is the documentation mismatch that drives audit recoupment. The OIG has cited this pattern repeatedly in chiropractic audits going back to its 2018 portfolio, which flagged chiropractic as carrying the highest improper payment rate in Medicare fee-for-service.

The chronic subluxation category under CMS’s own policy adds complexity. CMS does allow coverage for chronic subluxation when continued manipulation can be expected to result in some functional improvement, even if the condition will not fully resolve. But functional improvement must be documented. It must be measurable. Vague clinical impressions do not satisfy the standard. Practices that document improvement only at the initial visit and then carry forward template notes without demonstrating ongoing functional change are creating the evidentiary gap that payers exploit to reclassify ongoing care as maintenance.

What the documentation must show to protect active treatment status:

At each visit, objective findings must demonstrate change, either improvement in range of motion measurements compared to the prior visit, improvement on a standardized outcome measure such as the Oswestry Disability Index or the Neck Disability Index, or documented functional status changes tied to activities of daily living. Progress notes that show measurable improvement at visit three, stabilize, and then plateau without a documented acute exacerbation are the chart pattern that precedes reclassification.

When care genuinely transitions to maintenance, the correct compliance path is to stop billing Medicare for the manipulation, issue an Advance Beneficiary Notice before continuing treatment, and apply the GA modifier to the claim. The ABN is discussed in detail in section six below.

3. CMT Code Errors: Why Chiropractic Claims Get Denied for Region Count Mismatches

CPT codes 98940, 98941, and 98942 define the chiropractic manipulative treatment codes covered under Medicare and recognized by commercial payers. Their selection is determined entirely by the number of spinal regions treated at that visit. CMS recognizes five spinal regions: cervical, thoracic, lumbar, sacral, and pelvic.

98940 covers manipulation of one to two spinal regions. 98941 covers three to four regions. 98942 covers all five regions.

Key phrase: The billed CMT code must match the number of documented regions. A mismatch triggers automatic payer rejection.

The most common CMT coding error is a mismatch between the code billed and the number of regions documented in the clinical note. Payer algorithms flag this at the claim level before a human reviewer sees the chart. If 98941 is billed but the SOAP note documents adjustment to two regions, the system identifies an overcoding discrepancy. If 98940 is billed when four regions were treated, the practice has undercoded and left revenue on the table.

The documentation requirement is specific: the SOAP note must name the regions treated, and the specific vertebral levels within those regions must be identified. “Adjusted lumbar spine” does not establish which region was treated with the precision CMS requires. “Adjusted L3 and L4, lumbar region” does.

Medicare does not cover 98943, the extraspinal manipulation code, for chiropractic services. Chiropractors are limited to 98940, 98941, and 98942 under Medicare. Claims billed with 98943 to Medicare are denied.

4. The AT Modifier: Why This One Missing Element Gets Claims Denied?

This deserves its own section because the AT modifier functions differently from most billing modifiers. It is not supplemental information. It is the provider’s attestation that the treatment being billed is active and medically necessary.

CMS Billing Article A56616 states the standard directly: for Medicare purposes, a chiropractor must place an AT modifier on a claim when providing active or corrective treatment to treat acute or chronic subluxation. Claims submitted for CPT codes 98940, 98941, or 98942 without an AT modifier will be considered maintenance therapy and denied.

CMS also makes clear that the presence of the AT modifier does not automatically guarantee payment. Contractors may deny on medical review if the underlying documentation does not support active treatment status. Applying the modifier to a claim with inadequate PART documentation or with a chart that shows a clinical plateau does not protect the claim. It simply ensures the claim proceeds to medical review rather than auto-denying.

The AT modifier is not applicable to Medicare Advantage claims under the same automatic rules. Medicare Advantage plans maintain their own prior authorization and documentation requirements, which vary by plan and may differ materially from traditional Medicare rules. UnitedHealthcare’s Medicare Advantage plans, for instance, implemented new prior authorization requirements for chiropractic services in multidisciplinary and outpatient settings effective September 1, 2024, requiring authorization beyond six visits over eight weeks.

5. Prior Authorization Lapses: Why Claims Get Denied After Approval Changes?

Prior authorization requirements for chiropractic have been expanding across commercial and Medicare Advantage plans. UnitedHealthcare, through its Optum subsidiary, implemented prior authorization requirements for chiropractic manipulative therapy under Medicare Advantage plans nationally, effective September 1, 2024, excluding initial evaluations and services delivered in the home. Under this policy, the first six visits within eight weeks meeting coverage criteria became immediately approvable, with requests beyond that volume requiring medical necessity review.

Blue Cross Blue Shield of North Carolina implemented prior authorization requirements for physical therapy codes under its fully insured plans effective late 2024, processed through the Carelon portal.

These policy changes create denial exposure in two specific patterns. The first is billing before confirming the current authorization status for an established patient, given that authorization requirements can change mid-plan year without direct notification to the provider. The second is exceeding approved visit counts without requesting a concurrent review or extension before the authorization limit is reached.

Key phrase: A valid prior authorization does not guarantee payment if the diagnosis, visit frequency, or rendering provider NPI drifts outside the original approval terms.

A valid prior authorization does not guarantee payment if the treating provider’s NPI, the diagnosis, or the visit frequency drifts outside the terms of the original approval. Payer systems cross-reference claims against authorization records at submission. Discrepancies between what was authorized and what was billed generate automatic denials.

Eligibility verification that captures plan-specific chiropractic benefits, including visit limits, authorization requirements, and in-network status for the specific rendering provider, must occur before every episode of care, not only at initial enrollment.

6. ABN Failures: Why Compliance Gaps Get Claims Denied?

The Advance Beneficiary Notice of Non-coverage, Form CMS-R-131, is the required instrument when a Medicare-participating provider expects Medicare to deny a service that would otherwise be covered. For chiropractic practices, the two most common triggers for mandatory ABN issuance are when the provider believes the patient has reached maximum therapeutic benefit and treatment is transitioning to maintenance, and when the number of visits is approaching a threshold that Medicare or its contractors may use as a screening benchmark.

The compliance rule is direct: the ABN must be issued before the service is provided, not after the denial arrives. A retroactive ABN does not satisfy the requirement and does not shift financial liability to the patient.

Without a properly executed ABN, when Medicare denies the claim for maintenance care, the provider cannot bill the patient and absorbs the full charge. With a properly executed ABN, the patient makes an informed choice: Option 1 allows the provider to bill Medicare even with an anticipated denial, and the patient agrees to pay if Medicare does not. Option 2 asks Medicare not to be billed, with the patient paying directly. Option 3 means the patient declines the service.

The GA modifier must be appended to the claim when an ABN has been signed and the service is being billed to Medicare. The GX modifier applies when a voluntary ABN is issued for services that exceed frequency limits or where the provider is transitioning care proactively.

Excerpt: CMS released an updated ABN form (CMS-R-131) with a compliance deadline of May 12, 2026. Practices using the previous form do not meet current CMS requirements.

CMS released an updated ABN form (CMS-R-131) with a compliance deadline of May 12, 2026. Practices that have not updated their form templates to the current version as of that date are using a form that does not meet CMS requirements.

ABN use is not permitted for Medicare Advantage plans. Medicare Advantage has its own non-coverage notice requirements, and issuing a standard ABN for a Medicare Advantage beneficiary does not satisfy those requirements.

7. Bundling Errors: Why Claims Get Denied When Multiple Services Are Billed?

When chiropractic services are billed alongside other musculoskeletal or physical medicine procedures on the same date of service, National Correct Coding Initiative (NCCI) edits govern which code combinations are payable. CMS explicitly states that chiropractic practices treating patients should refer to NCCI and OPPS requirements before billing.

Modifier 59 indicates a distinct procedural service performed on the same date that would otherwise be bundled. Its correct application requires that the procedure represent a different session, different site, or different injury than the primary service. Using Modifier 59 as a blanket override on bundling edits without clinical documentation to support the distinction is a compliance risk that generates audit flags and can result in post-payment recoupment.

The most common chiropractic bundling scenario involves billing manipulation codes alongside physical medicine therapeutic services such as 97110 (therapeutic exercise) or 97140 (manual therapy). These are not automatically bundled, but when billed together, each service must have its own SOAP note justification tied to specific functional goals, not a generic “adjustment and exercises” notation. Documenting “therapeutic exercise to improve lumbar stability” is sufficient. Documenting “exercises performed” is not.

What Audit-Ready Chiropractic Documentation Looks Like?

The difference between a practice that survives Medicare and payer audits and one that receives recoupment demands is not the quality of care delivered. It is whether the clinical record, as written, tells the story that justifies the code billed.

Audit-ready chiropractic documentation contains the following elements at every visit:

The primary subluxation diagnosis with the specific vertebral level affected, not just the spinal region. The PART findings with at least two components documented, one of which is asymmetry or range of motion. A comparison to the prior visit’s objective findings, showing whether the condition has changed. The spinal regions treated, named by region and vertebral level, which must match the CMT code billed. The AT modifier applied when the treatment qualifies as active or corrective. Functional outcome measures that provide a quantifiable benchmark for improvement over the episode of care.

Progress notes do not need to be lengthy. They need to be specific. The question every chiropractic SOAP note must answer is: why is this visit medically necessary today? The answer must be in the objective findings, not in the subjective complaint section, and it must be different enough from the prior visit to demonstrate that the patient has not reached a plateau.

How to Appeal a Chiropractic Medical Necessity Denial?

When a chiropractic claim is denied for medical necessity, the appeal window and process depend on the payer. For Medicare, the first level of appeal is a redetermination, which must be filed within 120 days of the date on the initial denial notice. For commercial payers, appeal windows typically range from 60 to 180 days from the denial date, and missing the window forfeits the right to appeal.

The appeal package for a medical necessity denial must include the complete clinical documentation for the denied encounter, including the full SOAP note with PART findings, the treatment plan, any functional outcome measures on file, and a narrative that specifically addresses the denial reason cited in the Explanation of Benefits. A generic appeal letter that restates the diagnosis without addressing the payer’s stated reason for denial rarely succeeds.

Peer-to-peer review is available from most commercial payers and Medicare Administrative Contractors when a clinical determination drives the denial. Requesting a peer-to-peer call with the reviewing clinician is most effective when the denial cites clinical criteria that the treating provider’s documentation does address but that may not have been read in full. Peer-to-peer requests should be made promptly after the denial, typically within five to fourteen business days depending on the payer, before the standard appeal clock starts running.

Systemic denial patterns, where the same denial reason appears across multiple patients and the same payer, are not appeal problems. They are root cause problems. Resubmitting individual claims without addressing the documentation or coding pattern that generated the denials creates a cycle of rework without changing the outcome rate.

Why Chiropractic Practices Lose Revenue They Have Already Earned?

The denials described in this article are not random. Payer systems are engineered to identify specific documentation deficiencies, coding mismatches, and modifier failures before payment is released. The AT modifier missing from a Medicare claim does not trigger a human review. It triggers an automatic denial. A CMT code where the billed region count does not match the documented region count does not result in a question to the provider. It results in a rejected or denied claim.

Excerpt: Independent chiropractic practices are treating patients at clinical skill levels that their billing infrastructure does not consistently protect.

Independent chiropractic practices are treating patients at clinical skill levels that their billing infrastructure does not consistently protect. The gap between what a practice earns in the treatment room and what it collects from payers is not a reflection of the care provided. It is a reflection of whether the revenue cycle behind that care is built for chiropractic-specific payer rules or for generic claim processing.

How WeBill Health Defends Chiropractic Revenue Before a Denial Reaches You?

WeBill Health operates as an embedded revenue defense unit for independent and specialty chiropractic practices, not as a billing vendor that processes claims and waits to see what payers do. The distinction matters because the denials described in this article are not problems that originate at the appeal stage. They originate at the documentation stage, the coding stage, and the submission stage.

WeBill’s Denial Defense 2.0 uses payer behavior intelligence, including real-time scrubbing against Medicare, UnitedHealthcare, BCBS, and 500 or more payer rulesets, to identify AT modifier failures, CMT region mismatches, PART documentation gaps, and authorization discrepancies before a claim is submitted. The 98% clean claim rate and 48-hour submission guarantee are not positioning statements. They are operational metrics that result from catching the patterns this article describes at the pre-submission stage rather than the appeal stage.

Every chiropractic practice WeBill Health partners with has direct access to a dedicated US-based billing manager who understands the specialty’s specific denial landscape. There are no call centers, no ticket queues, and no black-box reporting. Weekly velocity reports give practice owners real-time A/R aging visibility and a clear line of sight into which payers are creating friction and why.

WeBill’s revenue share alignment model ties WeBill’s financial outcome directly to the practice’s collections performance. When a chiropractic practice loses revenue to preventable denials, so does WeBill Health. That structural alignment is the foundation of how WeBill approaches every claim.

Practices currently experiencing denial rates above industry benchmarks, carrying A/R aging beyond 60 days, or absorbing recoupment demands from Medicare or commercial payers can request a Revenue Health Audit. The audit identifies the specific denial categories driving the leakage, the coding patterns generating audit exposure, and the documentation gaps that need to be closed. It is a forensic review of where earned revenue is being lost and a concrete path to recovering it.

Chiropractic practices that have been burned by billing vendors who process claims without defending them deserve a partner whose livelihood depends on the same outcome as theirs. That is what WeBill Health is built to be.

WeBill Health is a specialty-focused Revenue Cycle Management and revenue defense company headquartered in Mountlake Terrace, Washington, serving independent and specialty practices nationally. To request a Revenue Health Audit for your chiropractic practice, visit webillhealth.com.

Why Chiropractic Claims Get Denied: Frequently Asked Questions

What is the PART system and why does Medicare require it?

The PART system is Medicare’s evidentiary standard for documenting spinal subluxation in chiropractic claims. PART stands for Pain and tenderness, Asymmetry or misalignment, Range of motion abnormality, and Tissue tone changes. CMS requires at least two PART components to be documented at every visit, with at least one being asymmetry or range of motion. If PART documentation is absent or vague, Medicare will deny the claim because there is no documented subluxation on record.

Can I bill Medicare for chiropractic care without the AT modifier?

No. CMS requires the AT modifier on all chiropractic manipulation codes (98940, 98941, 98942) when billing for active or corrective treatment. A claim submitted without the AT modifier is automatically treated as maintenance care by Medicare and denied. There is no appeal pathway for modifier omissions because the absence of the AT modifier is read as the provider’s own statement that the service is not active treatment.

What is the difference between active treatment and maintenance care in chiropractic?

Medicare defines active treatment as care where manipulation is expected to result in improvement or arrest of progression of the patient’s condition. Maintenance therapy is ongoing care for a stable condition with no expectation of additional objective clinical improvement. Maintenance care is never covered by Medicare. The distinction is determined by the objective findings in your clinical record, not by the number of visits or the patient’s preference.

How many regions can I bill on a single chiropractic visit?

CMS recognizes five spinal regions: cervical, thoracic, lumbar, sacral, and pelvic. You can bill 98940 for one to two regions, 98941 for three to four regions, and 98942 for all five regions. The number of regions you bill must match the regions documented in your SOAP note, or the claim will be flagged for overcoding or undercoding.

What should I do when a patient reaches maximum therapeutic benefit?

When a patient has reached maximum therapeutic benefit and treatment is transitioning to maintenance care, you must issue a properly executed Advance Beneficiary Notice (ABN, Form CMS-R-131) before the next service is provided. The ABN must be issued before the service, not after a denial. Once the ABN is signed, you append the GA modifier to the claim if billing Medicare, and the patient makes an informed choice about whether to continue and pay out of pocket.

How do I know if my prior authorization is still valid?

Prior authorization requirements and visit limits can change during a plan year without direct notification to your office. Verify current authorization status before every episode of care, not only at initial enrollment. Check for changes in visit limits, authorization requirements, and in-network status for your specific NPI. A claim billed outside the authorization terms will be denied even if a prior authorization is on file.

What makes the difference between a claim that gets paid and one that gets denied?

Documentation precision. Payer systems are engineered to identify specific documentation deficiencies, coding mismatches, and modifier failures before payment is released. The AT modifier missing from a claim triggers automatic denial. A CMT code that does not match documented regions triggers automatic rejection. Objective findings that show functional improvement or change distinguish active treatment from maintenance. The gap between paid and denied claims is almost never clinical quality. It is whether your SOAP notes give payers what they require to pay.

Is there a compliance deadline for updating my ABN form?

Yes. CMS released an updated ABN form (CMS-R-131) with a compliance deadline of May 12, 2026. Practices using the previous ABN form version do not meet current CMS requirements. If you are still using an older form, you must update your templates immediately.

What is the most common chiropractic coding error?

The most common error is a mismatch between the CMT code billed and the number of spinal regions documented in the clinical note. If 98941 is billed but only two regions are documented, the claim flags for overcoding. If 98940 is billed when four regions were treated, revenue is left on the table and the claim may flag for undercoding. Payer algorithms catch this discrepancy at the claim level before submission.

How do I bundle chiropractic services with physical medicine codes on the same date?

When billing manipulation codes with physical medicine services such as 97110 or 97140, each service must have its own SOAP note justification tied to specific functional goals. The bundling rules are not the issue. The documentation clarity is. Documenting “therapeutic exercise to improve lumbar stability” is sufficient and distinct. Documenting “exercises performed” is not and will trigger bundling denials.

What should a peer-to-peer review focus on?

A peer-to-peer review is most effective when the denial cites clinical criteria that your documentation actually addresses but may not have been fully read or understood. Request the peer-to-peer call promptly after the denial, typically within five to fourteen business days depending on the payer. Have your complete SOAP note, PART findings, and functional outcome measures available to discuss directly with the reviewing clinician.

How can I prevent medical necessity denials?

Every chiropractic SOAP note must answer one question with precision: why is this visit medically necessary today? The answer must be in objective findings, not subjective complaint. Compare your current visit findings to the prior visit to show whether the patient’s condition has changed. Document specific vertebral levels, not just regions. Include PART components with at least one being asymmetry or range of motion. Use standardized outcome measures like the Oswestry or Neck Disability Index to quantify improvement. These elements together create audit-ready documentation that satisfies payer requirements before a claim is submitted.