The AT modifier, active treatment and maintenance care
Medicare covers 98940, 98941 and 98942 when the patient is under active treatment, meaning there is a reasonable expectation that the condition will improve, or that continued care will arrest a deteriorating one. The AT modifier on the claim is the practice’s statement that the visit meets that standard. Once the patient has reached maximum improvement and care is keeping them where they are, the visit is maintenance, Medicare does not pay for it, and AT does not belong on the claim.
Maintenance visits billed to Medicare for a secondary plan’s denial go out without AT and with GA if the patient signed an Advance Beneficiary Notice. The GA is what makes the denial a patient balance rather than a contractual write-off. We check the treatment plan dates and the documented progress before assigning AT, because a review that finds AT on maintenance visits is a review that asks for money back.
Diagnosis coding and the initial-treatment date
Medicare requires a segmental and somatic dysfunction code from M99.01 through M99.05 as the primary diagnosis, one for each spinal region treated, with a secondary neuromusculoskeletal diagnosis supporting the need for care in that region. The number of regions the diagnoses cover has to match the code billed: a 98941 for three to four regions with a single M99 code is a CO-11 waiting to happen.
Item 14 of the claim has to carry the date of the initial treatment or the exacerbation that began the current episode, and Medicare uses it to judge how long the episode has been running. Initial and subsequent visit notes each have their own documentation elements, including the subluxation demonstrated by examination under the PART criteria. We verify that the regions, the diagnoses, the code level and the Item 14 date agree with one another on every Medicare claim before it goes.
What Medicare will not pay a chiropractor for
Everything a chiropractor does other than manual manipulation of the spine is excluded from Medicare coverage by statute: examinations, x-rays, therapeutic exercise, manual therapy, traction, electrical stimulation and supplies. They are never covered when a chiropractor performs them, and the patient is responsible for them. When they are billed to Medicare to obtain a denial for a secondary payer, they carry the GY modifier so the denial is clean and quick.
The practical problem is the front desk. A Medicare patient who receives an adjustment and fifteen minutes of therapeutic exercise owes for the exercise regardless of anything the claim says, and if that is not explained before the visit the practice ends up either absorbing it or arguing about it. We build the excluded services into the patient estimate so the conversation happens at scheduling.
Commercial plans, visit limits and the 97140 problem
Commercial chiropractic benefits usually come with an annual visit limit, often shared with physical and occupational therapy, and sometimes an authorization requirement after a set number of visits. Many plans delegate the benefit entirely to a chiropractic network manager such as American Specialty Health, which runs its own clinical review, its own tiering of providers and its own claim address. The patient’s card names the health plan; the payer that adjudicates the visit is the network.
Manual therapy, 97140, is bundled into chiropractic manipulation under NCCI unless it is performed on a separate region and billed with modifier 59, and the note has to name the region. An E/M on the same day as an adjustment pays only when a new problem or a significant change is evaluated and modifier 25 is supported. Billing 99213-25 on every visit is the fastest way a chiropractic practice gets flagged.
Chiropractic billing when half the practice is cash
Most chiropractic practices are a mix: insured patients, cash patients on a wellness plan, and personal injury patients whose bills are going to an auto carrier or an attorney. Each group has its own rules. Medicare requires that covered manipulation be billed to Medicare even for a non-participating provider, so a Medicare patient cannot simply be moved to the cash plan for covered visits. Personal injury claims go to the auto or liability carrier with the accident date and are not health plan claims at all; sent to the health plan, they return as CO-109.
We keep the three populations separate in your practice management system so that health plan claims, personal injury balances with lien documentation, and cash memberships are each tracked and reported on their own terms. The fee schedule stays consistent across them, which matters when a payer audits what cash patients were charged.
- Medicare, commercial, personal injury and cash tracked as separate populations
- ABN and GA workflow for maintenance care; GY for statutorily excluded services
- Lien and settlement follow-up on personal injury balances handled as its own A/R queue
Documentation that survives a review
Chiropractic claims are reviewed often, and the reviewers look at the same things each time: whether the treatment plan states goals, frequency and duration; whether progress toward those goals is measured with something objective rather than “patient reports feeling better”; whether the region count and diagnoses match the code; and whether the visit was active treatment or maintenance. We read notes against that list on a sample before denials arrive.
When a payer requests records, the response goes out with the specific policy language the payer applied, the treatment plan, and the notes for the dates in question, not the whole chart. Where a pattern of denials traces back to a documentation habit, the fix is a conversation with the clinician about the template.
