Medicare’s approach to covering chiropractic services is highly specific and limited to services deemed medically necessary under Part B. This government health insurance program for people aged 65 or older and certain younger people with disabilities only covers a small fraction of the services a chiropractor may offer. To qualify for payment, the treatment must be corrective in nature and directly address a spinal joint condition that is causing a neuromusculoskeletal problem. This focus on medical necessity means that routine, preventative, or maintenance care is generally excluded from coverage.
Defining the Covered Chiropractic Service
Medicare coverage is restricted almost exclusively to the manual manipulation of the spine to correct a subluxation. This specific service is billed using one of three Current Procedural Terminology (CPT) codes: 98940 (one to two spinal regions), 98941 (three to four regions), or 98942 (five spinal regions). These codes represent the adjustment performed by hand or with a manual device to the spinal column. The number of regions treated must correspond directly to the regions documented as having a subluxation.
Medicare does not cover any other services a chiropractor might provide, even if they are part of a comprehensive treatment plan. This exclusion includes examinations, X-rays, and physical therapy modalities such as heat, cold, or electrical stimulation. When a chiropractor orders or performs these non-covered services, the patient is responsible for the cost. Non-spinal adjustments, coded as 98943, are also excluded from the Medicare chiropractic benefit.
Qualifying Medical Necessity Diagnosis Codes
Medicare covers chiropractic treatment only for a spinal subluxation, defined as a misalignment or functional abnormality of a joint. This subluxation must result in a neuromusculoskeletal condition requiring manipulative treatment. To bill for this service, the provider must use two distinct diagnosis codes from the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) system.
The primary diagnosis code must be from the M99.0x series, representing segmental and somatic dysfunction or subluxation. The “x” is replaced by a number indicating the specific region being treated (e.g., M99.01 for cervical or M99.03 for lumbar). This code must specify the precise level of the subluxation, whether by region or by listing the exact bones involved. This diagnosis serves as the medical justification for the spinal manipulation.
A secondary diagnosis code is also necessary to demonstrate medical necessity. This code must describe the patient’s neuromusculoskeletal condition, such as pain, radiculopathy, or a site-specific joint condition. Common secondary codes include those for acute low back pain (e.g., M54.5) or cervicalgia (M54.2), provided the diagnosis is coded to the highest level of specificity. The secondary code links the patient’s symptoms directly to the subluxation being treated.
Coverage Distinction Between Active and Maintenance Care
A significant factor determining continued coverage is the distinction between active treatment and maintenance therapy. Medicare only covers active treatment, which is defined as care intended to achieve a significant, measurable improvement in the patient’s condition or to arrest its progression. This phase of care is corrective and is applied to acute or chronic subluxations with a reasonable expectation of functional recovery. The frequency of visits should decrease as the patient’s condition improves.
Maintenance therapy, conversely, is not covered by Medicare and includes services that seek to prevent disease, promote health, or maintain a chronic condition that is no longer expected to improve. Once a patient reaches maximum therapeutic benefit, meaning no further objective clinical improvement is expected, any continued treatment is considered maintenance care. At this point, Medicare coverage ceases as the treatment transitions from corrective to supportive. Providers must document objective measures, such as increased range of motion or reduced pain scores, that justify the care as active treatment.
Administrative Requirements for Billing and Documentation
To receive payment, providers must adhere to specific administrative and documentation requirements when submitting claims to Medicare. For all covered spinal manipulation services (CPT codes 98940, 98941, 98942) that qualify as active treatment, the billing modifier “AT” must be appended to the claim. The “AT” modifier signifies that the treatment is active/corrective, which is a mandatory requirement for Medicare payment consideration. Without this modifier, the service is automatically considered maintenance therapy and denied.
When a service is expected to be denied (e.g., transitioning to maintenance care or providing a non-covered service like an examination), the provider must use an Advance Beneficiary Notice of Noncoverage (ABN). If the patient signs the ABN, agreeing to pay if Medicare denies the claim, the modifier “GA” is used. If the provider expects denial but failed to obtain a signed ABN, the modifier “GZ” must be used; this ensures the claim is denied and prevents the provider from billing the patient.
Initial documentation is crucial for establishing medical necessity and must include a detailed history of present illness (HPI), a physical examination, and a formal treatment plan. The treatment plan must outline the recommended duration and frequency of care, specific treatment goals, and objective measures to evaluate the patient’s progress. This comprehensive record must clearly support the subluxation diagnosis and the need for manipulation to avoid claim denials.