Entity and doctrine specifics
Corporate practice application varies more here than in medicine. Some states apply a corporate practice doctrine to PT and chiropractic explicitly; others do not address them; others regulate through professional entity ownership rules alone. Isles Wellness, Inc. v. Progressive Northern Insurance Co., 703 N.W.2d 513 (Minn. 2005), applied corporate practice principles to chiropractic and physical therapy clinics, a reminder that the doctrine is not confined to medicine.1 Oregon’s SB 951 carves out PT and OT from its MSO restrictions, alongside dental and veterinary.2 Another case where the answer for these professions diverges from medicine within the same state.POPTS
Physician-owned physical therapy services (POPTS), a physician practice owning and operating a PT service, is restricted in some states through PT practice acts, and the American Physical Therapy Association has long advocated against it. Two distinct issues, often conflated:- State POPTS restrictions, whether a physician-owned entity may provide PT at all
- Federal Stark, physical therapy is a designated health service, so a physician referring to an entity in which they have a financial interest needs an exception, typically the in-office ancillary services exception with its supervision, location, and billing requirements
Medicare therapy specifics
Medicare has therapy-specific rules that generic billing setups handle badly: Plan of care certification. Therapy services require a plan of care established and periodically certified by a physician or non-physician practitioner. Missing or late certification is a common denial and a common audit finding. The KX modifier. Used to attest that services above the annual therapy threshold are medically necessary and supported by documentation. The therapy “cap” became a threshold with a medical review process rather than a hard limit, but the documentation obligation is real — appending KX without supporting documentation is an attestation you cannot back up.3 Multiple procedure payment reduction (MPPR). Payment is reduced for additional therapy units furnished in the same session. This is a contractual reduction, not a denial, and billers who don’t recognize it generate pointless appeals. The 8-minute rule. For time-based codes, the number of billable units is determined by total treatment minutes under CMS’s counting methodology. Get this wrong systematically and you have an overpayment across every affected claim. Therapy assistant modifiers. Services furnished in whole or substantial part by a PTA or OTA require modifiers and are subject to a payment differential. Therapy billing has more mechanical rules than most outpatient specialties, and they are the kind that produce systematic errors, the same mistake on every claim. That is exactly the shape that turns into a large overpayment finding. Audit your unit counting and modifier application early.High-volume billing operations
PT and chiropractic practices generate far more claims per clinician than most specialties: a patient may be seen two or three times a week for six weeks. Operational consequences:- Claim volume per clinician is high, so biller-to-clinician ratios differ from other specialties
- Small per-claim values mean a denial’s absolute value is low but the aggregate matters enormously
- Automation pays off faster here than anywhere else, eligibility, charge capture, scrubbing
- Visit authorization tracking is a core workflow: most payers authorize a limited number of visits, and exceeding the authorized count without a new authorization is a denial
- Plan-of-care expiration tracking is a second core workflow
Personal injury and attorney liens
The revenue stream that makes this vertical financially distinctive. A substantial share of PT and chiropractic revenue in some markets comes from patients injured in accidents, where payment comes from:- Auto insurance PIP (personal injury protection) in PIP states
- Third-party liability settlements, paid at case resolution
- Letters of protection or liens against a future settlement
PI revenue is not accounts receivable in the ordinary sense. It is a contingent claim on a future settlement, frequently reduced in negotiation, and it can age for years. Booking it at full billed charges materially overstates your financial position, which matters for your own management and enormously for any diligence process. Discount it based on your actual historical realization rate, and be prepared to show that rate. See How investors read MSO-PC financials.
Operationally, PI revenue also arrives as paper settlement checks, frequently made payable jointly to the practice and the patient or the attorney. Joint-payee endorsement is a workflow, not an afterthought. See Handle paper checks.
There are also ethical and legal constraints on relationships with referring attorneys — arrangements where an attorney refers patients and the practice reciprocates in some way can implicate state anti-kickback and fee-splitting statutes, and in some states specific restrictions on medical-legal referral relationships.
Launch pitfalls
- Assuming the medical CPOM answer applies to PT or chiropractic
- Missing POPTS restrictions where a physician group owns the PT service
- Missing Stark analysis on physician referrals to owned PT
- Systematic 8-minute rule errors
- Appending KX without supporting documentation
- Treating MPPR reductions as denials
- Missing visit authorization limits and plan-of-care expirations
- Booking PI revenue at billed charges
- Using a generic EHR that can’t track visit authorizations
- Attorney referral arrangements without checking state anti-kickback law
Sources
- Isles Wellness, Inc. v. Progressive Northern Insurance Co., 703 N.W.2d 513 (Minn. 2005).
- Or. S.B. 951 (2025), with carve-outs including PT/OT. Enrolled bill.
- CMS, Therapy Services. Confirm current threshold amounts and KX modifier requirements, they are updated annually.