How to Bill Medicare as a Chiropractor (Without Losing Your Mind or Your Money)

Let's be honest: Medicare billing isn't exactly the reason you went to chiropractic school. You got into this to help people move better, feel better, and live better — not to become a coding specialist with a side hustle in bureaucratic paperwork.

And yet, here we are.

The good news? Billing Medicare as a chiropractor isn't rocket science — it just requires knowing the rules of the game. Get it right, and you'll have a steady, reliable revenue stream. Get it wrong, and you're looking at denials, write-offs, and some very unhappy patients.

So let's get into it. Here's everything you and your team need to know.

1. Use the Right CPT Code (There Are Only Three — Easy Win)

Medicare doesn't cover every chiropractic service under the sun. In fact, when it comes to covered services, they keep it pretty tight. There are exactly three CPT codes you need to know:

98940: Chiropractic manipulative treatment (CMT); spinal, one to two regions
98941: CMT; spinal, three to four regions
98942: CMT; spinal, five regions

That's it. Think of them as small, medium, and large — the number of spinal regions treated determines which one you use. No guessing, no gray areas. Just make sure the code matches what actually happened in the treatment room.

2. Attach the Right Modifiers (Because Context Is Everything)

Modifiers are how you tell Medicare the story behind the claim. Think of them as the footnotes that keep you out of trouble. Here are the key ones for chiropractic:

AT (Active/Corrective Treatment) — This one's non-negotiable. If you're billing for active treatment, the AT modifier needs to be on the claim. No AT modifier = Medicare assumes it's maintenance care = denial. Don't skip this one.
GA (Waiver of Liability Statement on File) — Use this when you have an Advance Beneficiary Notice (ABN) on file and you suspect Medicare may not cover the service. It tells Medicare: "We did the right thing, warned the patient, and have the paperwork to prove it." If the claim gets denied, Medicare will automatically assign liability to the patient — meaning you can still collect. Smart move.
GY (Non-Covered Service — Intentional) — This one's for when you know a service isn't covered and you just need the denial in writing. It tells Medicare: "We know this isn't covered. We just need the paperwork." Great for patients who need documentation for a secondary insurance.

3. Document Like Your Reimbursement Depends on It (Because It Does)

Here's a truth that never gets old: if it isn't documented, it didn't happen — at least as far as Medicare is concerned. Solid documentation is what stands between you and a costly medical review.

Make sure your records include:

Chief complaint and all treated areas. If a patient comes in for cervical neck pain, you can only bill for the regions you actually treated and that are supported by their complaints. Treating additional regions without documented justification? That's a fast track to a denial.
Clear documentation of all treatment provided. No vague notes. Be specific about what you did and why.
Regular OATS assessments. These ongoing assessments show Medicare that treatment is producing measurable progress — which is exactly what they want to see to keep approving claims.
A detailed treatment plan with goals. Where is this patient headed? What are you trying to achieve, and by when? Medicare likes a roadmap.
- Correct completion of Boxes 14 and 15 on the HCFA form. Box 14 = Date of onset of current symptoms + qualifier 431
- Box 15 = Initial treatment date (the first time you treated this patient for their current injury/symptoms) + qualifier 454

It sounds like a lot, but once your team has a solid documentation rhythm, it becomes second nature.

4. Submit Claims on Time (365 Days — Don't Push Your Luck)

Medicare gives you 365 days from the date of service to submit a claim. Miss that window, and there's no wiggle room — you must write off the balance, and you cannot bill the patient. That's money gone forever.

Set up reminders, audit your aging report regularly, and treat that 365-day deadline like it owes you rent — because it kind of does.

Know Your Enrollment Type (This One Really Matters)

Not all Medicare providers are created equal. Your enrollment status dictates how you bill, what you can charge, and how payments flow. Here's the breakdown:

Participating Provider You've agreed to always accept assignment. That means you accept Medicare's approved amount as payment in full and only collect the deductible and coinsurance from the patient. In exchange, you get direct reimbursement and slightly higher approved amounts than non-participating providers. Reliable, predictable, and straightforward.

Non-Participating Provider You accept Medicare but haven't agreed to take assignment on every claim — you decide case-by-case. You can charge up to 15% above Medicare's approved amount (the "limiting charge"), but here's the catch: that puts patients on the hook for up to 35% of the approved amount (20% coinsurance + 15% limiting charge). You still must submit the claim, but if you don't accept assignment on a given claim, Medicare sends payment directly to the patient.

Opt-Out Provider You've formally opted out of Medicare entirely. You can set your own rates, but you must have a signed private contract with each Medicare patient confirming they understand Medicare won't reimburse them for your services. No claim submission required — but no Medicare reimbursement either.

Not sure which category you fall into? Check your enrollment status before submitting claims. Billing under the wrong status can create compliance headaches you really don't want.

The Bottom Line

Billing Medicare as a chiropractor comes down to four things: the right codes, the right modifiers, airtight documentation, and timely submission. Nail those, and you'll be in good shape.

That said, this guide is meant to be a starting point — not a substitute for expert guidance. Medicare rules evolve, edge cases happen, and sometimes you just need someone who does this every day. That's where we come in.

If you'd rather hand this off to a team that lives and breathes chiropractic billing, we'd love to chat. Schedule a free discovery with us here