The in-office ancillary services exception lets a physician refer a patient for designated health services, imaging, physical therapy, clinical laboratory testing, performed inside the physician's own practice, without the referral becoming prohibited under the Stark Law, the federal self-referral statute at 42 U.S.C. 1395nn. Physician practices rely on it to keep ancillary services in-house. Stark Law carries strict liability: a referral either satisfies every element of an exception or it does not. A practice that gets one prong wrong makes a prohibited referral, not a paperwork error, and every claim billed on it is an overpayment.
The Supervision Requirement
The supervision prong, at 42 CFR 411.355(b)(1), controls who may furnish the service. It has to be performed personally by the referring physician, by another physician in the same group practice, or by staff the referring physician or another group physician supervises under Medicare's own supervision rules for that service. A covering physician who is not actually a member of the group, or a technician supervised by someone who has left the practice, breaks this prong even when the paperwork still lists the group's name.
The Location Requirement: Same Building or Centralized Building
The location prong, at 42 CFR 411.355(b)(2), gives a group practice two paths. The same building test is satisfied when the office is open at least 35 hours a week with at least 30 hours of physician services, or open at least 8 hours a week with at least 6 hours of physician services and either the patient's own pattern of care is with the group or the referring physician is present when the service is ordered. “Same building” is defined at 42 CFR 411.351 as a structure or structures sharing a single U.S. Postal Service street address, excluding parking lots and loading docks. The alternative, a centralized building, is space the group owns or leases full-time for at least six months and uses exclusively for its own designated health services. A satellite suite shared with another practice, or leased only part-time, fails the centralized-building test.
The Billing Requirement
The billing prong, at 42 CFR 411.355(b)(3), ties the claim to who did the work. It has to be billed by the physician who performed or supervised the service, by the group under its own billing number, by an entity the physician or group wholly owns, or by a qualifying independent billing agent. A claim billed under a different group's number, or an arrangement that does not match who actually supervised the service, fails this prong regardless of the supervision and location facts.
Where Group Practices Lose the Exception
Before the three prongs matter, the practice has to qualify as a group practice under 42 CFR 411.352: a single legal entity, substantially the full range of each physician's services delivered through shared space and staff, and at least 75 percent of each member's patient care billed through the group. A practice paying physicians in a way that functions as a referral-sharing arrangement, rather than a genuine group, loses the exception before the supervision, location, or billing facts are ever reached. One way the location prong fails as a practice grows: an ancillary suite gets added without confirming it meets the same-building hours test or qualifies as a centralized building, and the gap goes undetected until an audit tests it. Because Stark Law is strict liability, a location failure voids the exception for every referral that relied on it.
A Stark Law violation does not require intent. One referral that fails a single prong of the in-office ancillary services exception is a prohibited referral, and every claim built on it is an overpayment.
Why Early Legal Counsel Is Critical
It is critical that physician practices promptly retain experienced healthcare defense counsel upon receiving a civil investigative demand, a grand jury subpoena, an audit notice, or other government inquiry touching self-referral compliance. Early legal intervention can protect the practice's rights, ensure appropriate responses to government requests, avoid inadvertent admissions, preserve relevant defenses, and allow counsel to communicate with investigators on the practice's behalf. Delaying legal representation can significantly affect the outcome of a matter and expose the practice to unnecessary risk.
How Health Law Alliance Can Help
Health Law Alliance defends physician practices and group practices in Stark Law, anti-kickback statute, and False Claims Act matters, including self-referral exposure from a failed in-office ancillary services exception. These exposures surface through claims-data analytics that match referral patterns to billing before a subpoena arrives, the detection method our analysis of data analytics in federal healthcare fraud cases describes. Our healthcare fraud defense attorneys handle these matters from the first government inquiry through resolution.
Health Law Alliance's attorneys have overseen 2,000+ audits and handled 5,000+ matters, with 25+ years of experience.
If a government inquiry has raised questions about your practice's in-office ancillary services arrangement, contact Health Law Alliance's healthcare fraud defense attorneys for a free, confidential consultation.
