Stark Law (Physician Self-Referral): Compliance Basics for Designated Health Services

The federal Physician Self-Referral Law — commonly called the Stark Law after its primary sponsor — at 42 USC § 1395nn prohibits a physician from referring Medicare patients for designated health services (DHS) to an entity with which the physician (or an immediate family member) has a financial relationship, unless an exception applies. Implementing regulations sit at 42 CFR §§ 411.350-411.357. Stark is strict liability — intent does not enter the analysis. Documentation does.

What the law actually prohibits

The Stark prohibition has three working parts: a referral, a designated health service, and a financial relationship.

Designated health services are defined at 42 CFR § 411.351 and listed at 42 CFR § 411.351 (definition of DHS). The categories:

• Clinical laboratory services
• Physical therapy services
• Occupational therapy services
• Outpatient speech-language pathology services
• Radiology and certain other imaging services
• Radiation therapy services and supplies
• Durable medical equipment and supplies
• Parenteral and enteral nutrients, equipment, and supplies
• Prosthetics, orthotics, and prosthetic devices and supplies
• Home health services
• Outpatient prescription drugs
• Inpatient and outpatient hospital services

If a service is not on the DHS list, Stark does not reach it.

Financial relationship is defined to include both ownership/investment interests and compensation arrangements. Both direct and indirect relationships count. The indirect-compensation-arrangement analysis at 42 CFR § 411.354(c) is the technically most demanding element and where complex group-practice and joint-venture structures most often falter.

Referral is defined broadly at 42 CFR § 411.351 to include the request by a physician for the item or service, the establishment of a plan of care that includes the service, or the certification or recertification of need for the service. A physician ordering a lab test in the EHR is a referral.

Two structural consequences:

• Strict liability. A documentation defect, a missed signature, or an expired arrangement renders the underlying claims non-payable regardless of how the underlying clinical care was delivered or whether anyone intended to violate the statute.
• Per-claim exposure. Each non-payable claim is a separate exposure with its own refund, CMP, and FCA-by-recklessness analysis.

Exceptions and how they actually function

The Stark exceptions are at 42 CFR §§ 411.355 through 411.357. They are categorized into ownership-interest exceptions, compensation-arrangement exceptions, and exceptions applicable to both. Unlike AKS safe harbors, Stark exceptions are not voluntary — fitting an exception is the only way an otherwise-prohibited arrangement is permissible. Failure to fit any exception means the prohibition applies and the referral is non-compliant.

Exceptions most relevant to medical practices:

• In-office ancillary services at 42 CFR § 411.355(b). The cornerstone exception for group practices delivering DHS in-office (lab, imaging, PT). Three element groups: who performs (referring physician, group-practice physician, or supervised individual), where performed (same building or centralized building of the group practice), and who bills (referring physician, group, or wholly-owned entity).
• Physician services at 42 CFR § 411.355(a). Services personally performed or supervised by another group physician.
• Employment at 42 CFR § 411.357(c). Bona fide employment relationships with productivity-based compensation tied to the employee's personally-performed services.
• Personal service arrangements at 42 CFR § 411.357(d). Written, signed, one-year minimum, FMV, scope-defined.
• Rental of office space and equipment at 42 CFR §§ 411.357(a) and (b). Written lease, set rent at FMV, one-year minimum, commercial reasonableness.
• Bona fide investment in publicly-traded securities and mutual funds at 42 CFR § 411.356(a).
• Value-based arrangements at 42 CFR § 411.357(aa)–(cc). Added by the December 2020 Stark final rule.
• Limited remuneration to a physician at 42 CFR § 411.357(z). New 2020 exception covering up to a defined annual aggregate ($5,000-range, inflation-adjusted).

The group-practice definition at 42 CFR § 411.352 is itself a technical structure with its own elements: single legal entity, two or more physicians, full range of services through joint use of facilities and equipment, substantially-all-services test (75% threshold), unified business standard, and centralized decision-making. Many "groups" that operate informally as such fail one or more group-practice elements when examined.

How enforcement actually works

Stark trips practices that thought their in-office X-ray was covered under the ancillary services exception when in fact a same-building element or a group-practice element failed. Enforcement channels:

• CMS Self-Referral Disclosure Protocol (SRDP). Practices that identify a Stark exposure self-disclose to CMS through the SRDP process. CMS negotiates a settlement amount calculated against statutory factors, typically substantially below 1x of total claim value, depending on the nature of the violation and the cooperation of the disclosing entity.
• OIG SDP for Stark-with-AKS overlap. Where Stark exposure exists alongside AKS exposure, the matter goes to OIG SDP rather than SRDP — see our SDP guide.
• DOJ False Claims Act. Stark-tainted claims submitted with knowledge or reckless disregard of the violation are FCA-exposed. DOJ runs Stark-as-FCA cases, often initiated by qui tam relators under 31 USC § 3730.
• CMS audit channels. MAC, RAC, UPIC, and SMRC contractors can identify Stark exposure during billing reviews and refer to OIG or DOJ — see the Medicare TPE audit response guide.

Settlement values vary materially. SRDP self-disclosures have resolved in the high-five-figure to low-eight-figure range, dominated by lease and compensation-arrangement defects. DOJ Stark-as-FCA cases routinely settle in the seven- to nine-figure range with corporate integrity agreements.

What practices most often miss

The recurring Stark exposures across practice-side compliance reviews:

• Lease drift. A medical-office lease at FMV at execution; three years later the practice subleased a portion to a referring imaging center at a below-FMV rate. The lease exception failed on the FMV element the moment the sublease was signed.
• Group-practice element failure. A "group" that doesn't actually meet the 42 CFR § 411.352 elements — substantially-all services, unified business, centralized governance — cannot use the in-office ancillary services exception.
• Same-building or centralized-building defect. In-office ancillary services performed at a location that does not meet the same-building test under 42 CFR § 411.355(b)(2).
• Compensation tied to DHS volume. Productivity bonuses that include the value or volume of designated health services referred by the physician fail the personal-services exception and (for employees) the employment exception.
• Missing signatures or expired terms. The 90-day signature grace period at 42 CFR § 411.353(g) and the temporary noncompliance provisions at 42 CFR § 411.353(f) provide narrow cure paths. Outside those windows, the defect renders the arrangement non-compliant.
• Recruitment arrangements drift. Physician recruitment arrangements under 42 CFR § 411.357(e) have specific geographic and practice-establishment elements; drift in either dimension breaks the exception.

The arrangements that survive review are the ones with contemporaneous documentation: signed agreement, FMV opinion at execution, scope-of-services defined, annual review with a checked element list, and a cure-or-disclose workflow for any defect identified mid-stream.

State-law overlay

Several states have physician self-referral statutes that reach further than federal Stark:

• California Business & Professions Code § 650.01 reaches all-payer (not just Medicare) self-referral and includes a structured list of DHS categories with state-specific exceptions.
• New York Public Health Law § 238 and Education Law § 6531 prohibit physician self-referral for clinical laboratory, pharmacy, radiation therapy, and several other categories, with state-specific definitions.
• Florida Patient Self-Referral Act, F.S. § 456.053, requires disclosure of investment interests and limits referrals to designated entities.
• Illinois, Maryland, New Jersey, Connecticut maintain narrower state self-referral statutes layered on top of federal Stark.

A federally-compliant arrangement can still violate state law. State medical-board enforcement is independent of CMS, and state false-claims-act recoveries on Medicaid-side claims add a parallel exposure layer. Counsel evaluates both layers when papering any DHS arrangement.

Compliance checklist

Before any financial arrangement between the practice and a referring physician — or before any DHS arrangement under in-office ancillary services:

• [ ] Identify whether the service is a designated health service under 42 CFR § 411.351
• [ ] Identify the financial relationship (ownership/investment or compensation, direct or indirect)
• [ ] Identify the Stark exception relied upon, by citation
• [ ] Confirm every element of the exception is met, in writing, on the face of the arrangement file
• [ ] Written, signed, and dated agreement; one-year minimum where the exception requires it
• [ ] FMV opinion or benchmark contemporaneous with execution; refresh on material amendment
• [ ] Compensation not tied to the volume or value of DHS referred by the physician (or, where productivity is permitted, only personally-performed services counted)
• [ ] Group-practice elements documented for any in-office ancillary services reliance
• [ ] Same-building or centralized-building test documented for in-office ancillary services
• [ ] 90-day signature cure protocol in place for any signature lag
• [ ] Annual arrangement review with element-by-element re-verification
• [ ] SRDP-decision protocol in place for any identified noncompliance — counsel decides whether to self-disclose, cure, or treat as a 60-day overpayment
• [ ] State-law analog reviewed for any state in which the practice or referring physician operates

Restraint about outcomes

Stark Law is strict-liability and unforgiving on documentation. No template, checklist, or vendor can preempt a CMS or DOJ determination that an arrangement fails an exception. What rigorous documentation does is shrink the surface area, capture exception-fit contemporaneously, and position the practice for SRDP resolution at the lowest reasonable settlement value if a defect surfaces later.

This guide is not legal advice. The Stark analysis on any specific arrangement is a legal determination; consult outside healthcare counsel before papering anything that involves a physician's financial relationship with the practice or with an entity providing designated health services.

How d3rx fits

The d3rx compliance binder holds the source-grounded administrative documentation a Stark-defensible program is built from — the financial relationships log, the lease and compensation arrangement file, the annual element-review checklist, group-practice documentation, and the cure-or-disclose decision log. The d3rx audit defense workflow supports the SRDP, OIG SDP, and DOJ parallel-track handling that Stark matters often require. d3rx does not represent the practice in any CMS, OIG, DOJ, or state proceeding and does not replace counsel; it is a point-in-time administrative documentation aid that counsel and the practice work from.