A chiropractic clinic treats a Medicare patient for low back pain over several weeks. The patient improves, then keeps coming in to maintain progress. The visits look the same in the schedule, but Medicare sees them very differently. Once care shifts from active treatment to maintenance, the billing approach has to change too.

This article explains how chiropractic coding works, what Medicare requires, and how clinics can avoid the most common claim problems.

Coding Chiropractic Manipulative Treatment

Chiropractic manipulative treatment (CMT) is reported with CPT codes based on the number of spinal regions treated:

• 98940 for one to two spinal regions

• 98941 for three to four spinal regions

• 98942 for five spinal regions

• 98943 for extraspinal regions, such as the extremities

The documentation for each visit should identify which regions were treated and why. Billing 98941 when the note only supports two regions is a common audit finding.

Diagnosis coding should support the regions treated. A claim for three or four regions generally needs diagnoses that relate to each region being manipulated.

What Medicare Covers and What It Does Not

Medicare's coverage of chiropractic services is narrow. Medicare Part B covers manual manipulation of the spine to correct a subluxation. That means:

• Only spinal CMT codes (98940 through 98942) are covered by Medicare

• Extraspinal manipulation (98943) is not covered by Medicare

• Examinations, X-rays ordered by the chiropractor, and therapy services are not covered when performed by the chiropractor

The subluxation must be documented, either through an X-ray or through a physical examination that meets Medicare's documentation requirements. Medicare also expects a treatment plan with goals and measures of progress.

Commercial plans and Medicaid programs often cover a broader range of chiropractic services, but many have visit limits, prior authorization requirements, or medical necessity criteria of their own. Verifying benefits before the first visit avoids surprises later. This piece on chiropractic billing with insurance verification covers the front-end side in more detail.

Active Treatment Versus Maintenance Care

This is where many chiropractic claims go wrong. Medicare covers active or corrective treatment, where there is a reasonable expectation of improvement in the patient's condition. Once the patient reaches maximum improvement and care is aimed at maintaining that level, Medicare considers the treatment maintenance therapy, which is not covered.

The AT modifier is required on Medicare claims for active treatment. Without it, the claim is treated as maintenance and denied.

When a patient continues treatment after moving into maintenance, the clinic should:

• Stop using the AT modifier

• Issue an Advance Beneficiary Notice before the service if the clinic expects Medicare to deny it

• Use the GA modifier when a valid ABN is on file

Documentation of progress, including objective measures and updated goals, is what supports continued use of the AT modifier. Notes that look identical visit after visit make it hard to show active improvement.

Documentation That Holds Up in Review

Chiropractic services are a frequent focus of medical reviews. Strong documentation typically includes:

• The initial visit, with history, examination, diagnosis, and treatment plan

• The specific subluxation and how it was identified

• Treatment goals with measurable outcomes

• Subsequent visits with subjective complaints, objective findings, the regions treated, and progress toward goals

• Re-evaluations at reasonable intervals to update the plan

Templates can help with consistency, but cloned notes that repeat the same findings every visit raise concerns. Each note should reflect what actually happened at that encounter.

Commercial Payer Considerations

Outside of Medicare, clinics should track each major payer's policies on:

• Annual visit limits for chiropractic care

• Whether E/M services on the same day as CMT require modifier 25

• Coverage for therapeutic exercises, manual therapy, and modalities

• Prior authorization after a set number of visits

Billing an E/M service with CMT on the same day is allowed when the E/M is significant and separately identifiable, such as an initial evaluation or a new problem. Routine pre-manipulation assessment is considered part of the CMT code.

Clinics that want help sorting out payer enrollment and coverage rules can learn more here about how outside teams handle that work.

Therapy Services and Modalities in Chiropractic Care

Many chiropractic clinics also provide therapeutic exercises, manual therapy, and modalities such as electrical stimulation or ultrasound. Commercial payers often cover these services, but billing them adds complexity.

Timed therapy codes generally require documentation of the minutes spent on each service. When manual therapy is billed on the same day as CMT, many payers require that it be performed on a different body region than the manipulation, with a modifier such as 59 or an X modifier to show the distinction. Payer policies differ, so clinics should confirm each plan's rules before adding these services to their routine billing.

Clear patient communication rounds out the process. Many patients do not realize that Medicare covers only part of chiropractic care or that their commercial plan limits visits each year. Explaining coverage at the first visit, and again when care shifts to maintenance, helps patients make informed decisions and reduces unpaid balances. A simple written summary of what the patient's plan covers can save the front desk many difficult conversations later in the treatment course.

The Takeaway

Chiropractic billing and coding come down to accurate region counts, careful separation of active and maintenance care, and documentation that shows progress. Clinics that understand Medicare's narrow coverage and track each commercial payer's limits can keep claims clean and patients informed about what their insurance will cover.