Stark Law and Anti-Kickback Compliance in Healthcare M&A

Healthcare M&A transactions carry a category of regulatory risk that does not appear in general commercial acquisitions: physician self-referral and anti-kickback exposure. The Stark Law and the Anti-Kickback Statute govern financial relationships between healthcare entities and the physicians who refer patients to them, and violations of either statute can generate Medicare repayment obligations, Civil Monetary Penalties, False Claims Act liability, and exclusion from federal healthcare programs. In a healthcare acquisition, these risks transfer with the business. An acquirer that closes without systematic Stark and AKS diligence inherits the target's compliance history, including any violations that occurred years before the transaction.

This sub-article is part of the Healthcare M&A Legal Guide. It addresses the Stark Law framework under 42 USC 1395nn, the distinction between Stark exceptions and AKS safe harbors, the bona fide employment and personal services arrangement exceptions, fair market value and commercial reasonableness as independent requirements, the Anti-Kickback Statute's intent-based scienter standard, the principal AKS safe harbors, physician investment in ambulatory surgery centers, the 2020 Sprint final rule modifications for value-based arrangements, diligence protocols for physician compensation arrangements, the Self-Referral Disclosure Protocol and OIG Self-Disclosure Protocol, advisory opinions, indemnification and escrow structures for compliance exposure, and integration remediation planning.

Acquisition Stars advises buyers, sellers, and health system clients on healthcare M&A regulatory compliance, including Stark and AKS diligence, self-disclosure strategy, and post-closing integration. Nothing in this article constitutes legal advice for any specific transaction.

The Stark Law Framework: 42 USC 1395nn, the DHS List, and Strict Liability

The Ethics in Patient Referrals Act, codified at 42 USC 1395nn and universally known as the Stark Law, prohibits a physician from making a referral to an entity for the furnishing of designated health services covered by Medicare when the physician or an immediate family member has a financial relationship with that entity, unless a specific statutory or regulatory exception applies. The law also prohibits the entity from submitting a claim to Medicare for services furnished pursuant to a prohibited referral. Both the prohibition on referrals and the prohibition on billing operate simultaneously, meaning that a single compensation arrangement can generate dual exposure: the physician violates the statute by making the referral, and the entity violates it by billing for the resulting services.

The designated health services (DHS) list defines the scope of services covered by the Stark Law. DHS includes: clinical laboratory services; physical therapy, occupational therapy, and outpatient speech-language pathology services; radiology and certain other imaging services (including MRI, CT, and ultrasound); 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; and inpatient and outpatient hospital services. The breadth of the DHS list means that virtually every acute care hospital, health system, imaging center, laboratory, home health agency, and specialty clinic that bills Medicare for patient services is subject to the Stark Law's requirements with respect to its financial relationships with referring physicians.

The strict liability character of the Stark Law is its most consequential structural feature from a transactional perspective. Unlike the Anti-Kickback Statute, which requires proof of knowing and willful conduct, Stark imposes liability as a matter of law whenever a prohibited financial relationship exists and a referral occurs outside an applicable exception. Good faith reliance on legal advice, the absence of any intent to circumvent the statute, and the existence of a legitimate business purpose for the arrangement are not defenses to Stark liability. This means that a target's physician compensation arrangements that were structured in good faith by qualified healthcare counsel but that do not technically satisfy exception requirements will generate Stark exposure for an acquirer who assumes the target's Medicare billing obligations. The consequence in a healthcare acquisition is that diligence must identify not just intentional misconduct but also technical noncompliance, which is the more common finding.

Stark Exceptions vs. AKS Safe Harbors: A Critical Distinction

The Stark Law and the Anti-Kickback Statute each operate through a permissive framework: the baseline rule prohibits the conduct, and then specific exceptions or safe harbors carve out arrangements that satisfy defined requirements. The terminology differs because the legal structures are different. Stark exceptions are mandatory and exhaustive: if a financial relationship between a physician and a DHS entity does not fit within one of the statute's enumerated exceptions, the Stark prohibition applies without regard to intent or business purpose. AKS safe harbors are voluntary and protective: an arrangement that satisfies a safe harbor is protected from AKS prosecution, but an arrangement that does not fit any safe harbor is not automatically illegal. It may still be lawful if the parties lack the requisite intent to induce referrals.

This structural difference has practical implications for healthcare M&A. For Stark purposes, every physician financial relationship must be mapped to a specific exception. There is no residual category of "reasonable arrangements" outside the enumerated exceptions. For AKS purposes, an arrangement outside a safe harbor carries criminal risk proportional to the evidence of intent, but the absence of safe harbor coverage does not automatically establish a violation. In practice, healthcare lawyers structure physician compensation arrangements to satisfy both the applicable Stark exception and the analogous AKS safe harbor simultaneously, because satisfying both frameworks simultaneously eliminates exposure under both statutes. Diligence in a healthcare acquisition should identify which arrangements satisfy both, which satisfy only one, and which satisfy neither.

The principal Stark exceptions that apply in compensation arrangements include the bona fide employment exception, the personal services arrangements exception, the fair market value compensation exception, the group practice exception (for in-office ancillary services), the academic medical center exception, the isolated transactions exception, and the indirect compensation arrangements exception. Each exception has specific technical requirements regarding the existence of a written agreement, the compensation structure, the term and termination provisions, and the relationship between compensation and referral volume. Missing a single element of an applicable exception eliminates the protection, even if the arrangement is economically reasonable and the parties acted in good faith.

Bona Fide Employment Exception

The bona fide employment exception under 42 USC 1395nn(e)(2) protects amounts paid by an employer to a physician employee for employment in the provision of services if the employment is for identifiable services, the remuneration is consistent with the fair market value of the services, the remuneration is not determined in a manner that accounts for the volume or value of referrals by the physician, and the arrangement would be commercially reasonable even if no referrals were made. The bona fide employment exception is the most frequently used Stark exception in hospital and health system acquisitions, because the acquisition of a physician practice typically results in the target's physicians becoming employed by the acquiring entity.

The exception does not require that the employment relationship be structured as traditional W-2 employment. Arrangements that are properly characterized as employment under common law agency principles qualify even if the physician receives benefits, malpractice coverage, and other incident-of-employment terms customary in the healthcare industry. The key requirements that generate compliance failures in practice are the prohibition on compensation that accounts for referral volume and the requirement that the arrangement be commercially reasonable independent of referrals. Productivity-based compensation formulas that use work relative value units as the productivity metric are generally permissible because wRVU compensation reflects the physician's own professional services rather than the downstream ancillary services generated by referrals. Compensation formulas that include bonuses tied to facility ancillary revenue, imaging volume, laboratory orders, or other metrics that reflect the quantity of referrals made by the physician raise direct exception compliance questions.

In the M&A context, the bona fide employment exception analysis requires diligence not just of the written employment agreement but of how compensation is actually calculated and paid. Agreements that facially satisfy the exception may be operated in ways that generate prohibited compensation through discretionary bonuses, informal side arrangements, or compensation committee adjustments that are not reflected in the written agreement. Diligence should include review of payroll records, compensation committee minutes, and any amendments or addenda to the base employment agreements, as well as interviews with compliance and finance personnel to understand how compensation formulas are applied in practice.

Personal Services Arrangements Exception

The personal services arrangements exception under 42 USC 1395nn(e)(3) and 42 CFR 411.357(d) protects compensation arrangements between a physician and a DHS entity that satisfy seven specific requirements. The arrangement must be set out in writing and signed by the parties. It must specify the services covered. The aggregate services contracted for must not exceed what is reasonable and necessary for the legitimate business purposes of the arrangement. The term must be for at least one year. The compensation must be set in advance, consistent with fair market value, and not determined in a manner that accounts for the volume or value of referrals. The services must not involve the counseling or promotion of a business arrangement that violates any federal or state law. And the arrangement must be commercially reasonable even if no referrals were made between the parties.

The personal services arrangements exception is used primarily for medical director agreements, on-call compensation arrangements, administrative service agreements, and consulting arrangements between hospitals or health systems and physicians who are not W-2 employees. Medical director agreements are among the most frequently scrutinized arrangements in healthcare M&A diligence because they are common, they often involve significant compensation, and the services specified in the agreement are sometimes poorly defined or not actually performed in the manner described. A medical director agreement that pays a physician $150,000 annually for eight hours of administrative service per month may satisfy FMV requirements if survey data supports that compensation level for the specified service volume, or it may not, depending on the specialty and the nature of the services. It will fail the exception entirely if the physician does not actually provide the contracted services.

On-call compensation arrangements present distinct compliance challenges because on-call pay has historically been an area of significant CMS scrutiny. CMS has acknowledged that on-call compensation can be legitimate but has also expressed concern that on-call agreements can be used as a mechanism to compensate physicians for referral relationships under the guise of covering service obligations. Diligence on on-call agreements should examine whether the call coverage obligation is real and documented, whether the compensation is consistent with FMV for on-call coverage in the relevant specialty and market, whether call logs or other records document actual call coverage provided, and whether the compensation level has been reviewed and approved by the entity's compliance program.

Fair Market Value Compensation Standard

Fair market value is a defined term under the Stark Law regulations (42 CFR 411.351) and is a required element of virtually every Stark compensation exception. The regulatory definition provides that FMV means the value in arm's-length transactions consistent with the general market value, which is the price that an asset would bring as a result of bona fide bargaining between well-informed buyers and sellers who are not otherwise in a position to generate business for each other. For physician compensation, this means the compensation that would result from bona fide bargaining between an entity and a physician who are not otherwise in a referral relationship, in the relevant geographic and specialty market, without regard to the volume or value of referrals.

In practice, healthcare entities establish FMV through three principal methodologies: survey-based benchmarking against published compensation surveys (MGMA, SCA, AMGA, Sullivan Cotter, Gallagher), income approach analysis, and market approach analysis. Survey-based benchmarking is the most widely used method for physician employment compensation, because published surveys provide detailed specialty-level compensation data by percentile that allows entities to position a physician's compensation relative to the market. A physician compensated at or below the 75th percentile of relevant survey data, with documentation showing how the specific percentile was selected based on specialty, experience, and geographic market, has a defensible FMV position. Compensation above the 75th percentile requires additional documentation justifying the higher positioning, and compensation at or above the 90th percentile attracts significantly greater CMS scrutiny.

A formal written FMV opinion from a qualified independent valuation firm provides the highest level of FMV documentation. Such opinions are typically required for high-value arrangements (medical director fees above specified thresholds, compensation at or above the 75th percentile, and arrangements with physicians who generate significant referral volume to the entity). In M&A diligence, the absence of formal FMV documentation for significant physician compensation arrangements is itself a compliance finding, because it means the entity relied on informal or undocumented benchmarking that cannot withstand government scrutiny.

Commercial Reasonableness as an Independent Requirement

Commercial reasonableness is a separate and independent requirement from fair market value under the Stark Law. The Stark regulations define a commercially reasonable arrangement as one that makes commercial sense, is of a type that a reasonable entity would enter into for a legitimate business purpose in the absence of referrals. This definition matters because it is entirely possible for an arrangement to be compensated at fair market value while still failing the commercial reasonableness standard. The classic example is a medical directorship agreement that pays a physician FMV rates for services that the entity does not actually need, or that the physician does not actually provide. The compensation may be within FMV survey ranges, but if a reasonable entity would not enter into the arrangement independent of its referral relationship with the physician, the arrangement is not commercially reasonable.

The 2020 Sprint final rule added explicit regulatory language confirming that commercial reasonableness and FMV are two distinct analytical steps. CMS made clear in the Sprint rulemaking that an arrangement can be commercially reasonable even if it does not result in profit for one or more of the parties, and that the commercial reasonableness analysis focuses on whether the arrangement makes business sense, not on whether it generates a positive financial return. This clarification was important for arrangements such as hospital-employed physician programs where the hospital sustains financial losses on physician employment but receives legitimate value through care coordination, quality programs, and service line integration that cannot be captured in a simple revenue-minus-expense calculation.

In M&A diligence, commercial reasonableness failures often appear in arrangements where the documented services have little relationship to the entity's actual operations, or where the quantity of services contracted for substantially exceeds what the entity's operations could legitimately require. A critical care medical directorship for a facility with five ICU beds, compensated for 20 hours per week of administrative service, raises commercial reasonableness questions about whether the service volume is genuinely required. Diligence should examine not just whether a written agreement exists but whether the services described are actually needed, actually performed, and actually documented through contemporaneous records.

The Anti-Kickback Statute: Intent-Based Scienter and the One-Purpose Test

The Anti-Kickback Statute (42 USC 1320a-7b(b)) prohibits knowingly and willfully offering, paying, soliciting, or receiving any remuneration, directly or indirectly, overtly or covertly, in cash or in kind, to induce or reward the referral of an individual for, or the purchasing, leasing, ordering, or arranging for, any item or service covered by a federal healthcare program. Unlike the Stark Law, AKS is a criminal statute with a knowledge and intent requirement. The government must prove that the defendant knew that the conduct was unlawful and intended to violate the law.

The practical impact of the intent requirement is significantly constrained by the one-purpose test, which has been adopted by multiple federal circuit courts. Under the one-purpose test, a payment violates the AKS if one purpose of the payment is to induce referrals of federal healthcare program business, even if the payment also has other legitimate purposes. This means that a physician compensation arrangement that pays FMV for genuine medical director services but where the parties also expect the arrangement to maintain or enhance the physician's referral relationship with the entity can violate AKS if the government can establish that inducing referrals was even one purpose of the arrangement. The one-purpose test substantially narrows the gap between AKS's intent requirement and Stark's strict liability framework in practice.

Knowing and willful conduct under AKS does not require actual knowledge of the specific statute being violated. Courts have held that awareness that the conduct was generally unlawful, or that it was the type of conduct prohibited by law, is sufficient. In the healthcare context, this means that entities and physicians who have been through compliance training and are aware of federal restrictions on healthcare financial arrangements cannot claim ignorance of the general regulatory framework as a defense. AKS violations are felonies punishable by up to 10 years imprisonment, criminal fines, exclusion from federal healthcare programs, and civil monetary penalties. Because AKS violations constitute false claims under the False Claims Act when the tainted services are billed to Medicare or Medicaid, a single AKS violation can generate treble damages and per-claim civil penalties under the FCA.

AKS Safe Harbors: Employment, Investment, ASC, Space, Equipment, Personal Services, and Discounts

The OIG has promulgated safe harbor regulations under AKS (42 CFR 1001.952) that specify arrangements which, if structured to satisfy all applicable requirements, are protected from AKS prosecution. The employment safe harbor (42 CFR 1001.952(i)) protects amounts paid by an employer to a bona fide employee for employment in the provision of covered items or services. The employee must be a bona fide employee under the Internal Revenue Code, and the compensation must be for legitimate employment services and not for referrals. This safe harbor closely parallels the Stark bona fide employment exception and is typically analyzed jointly with that exception.

The investment interests safe harbor (42 CFR 1001.952(a)) protects returns on investment in publicly traded entities and in small entities meeting specified criteria. For small entity investment interests, the safe harbor requires that no more than 40 percent of the entity's investment interests be held by investors in a position to make or influence referrals, that the entity not loan funds or guarantee loans to investors in a position to make referrals, that investment returns be proportional to investment and not based on referral volume, and that the entity not market items or services to investors differently than to non-investor patients. The space and equipment rental safe harbors (42 CFR 1001.952(b) and (c)) protect rental payments for the use of office space and equipment that are set in advance, consistent with FMV, for a term of at least one year, covering specified space or equipment, and not determined in a manner that accounts for referral volume.

The personal services and management contracts safe harbor (42 CFR 1001.952(d)) protects compensation arrangements for personal services that satisfy requirements parallel to but distinct from the Stark personal services arrangements exception: the arrangement must be set out in a written agreement signed by the parties, must specify the services to be provided, must cover all services to be provided between the parties (avoiding the use of multiple separate agreements to fragment a single relationship), must provide for aggregate compensation that is consistent with FMV, must not be determined in a manner that accounts for referral volume, and must serve a commercially reasonable business purpose. The discount safe harbor (42 CFR 1001.952(h)) protects discounts on items or services that are properly disclosed and reflected in the claims submitted to federal healthcare programs, ensuring that the government, not the healthcare entity, receives the benefit of the discount.

Physician Investment in Ambulatory Surgery Centers

Physician ownership of ambulatory surgery centers is a recurring compliance issue in healthcare M&A because ASCs are a common target for acquisition and because physician ownership structures that were established before the transaction may or may not satisfy the AKS ASC safe harbor requirements. The AKS provides four separate ASC safe harbors (42 CFR 1001.952(r)): the surgeon-owned ASC safe harbor, the single specialty ASC safe harbor, the multi-specialty ASC safe harbor, and the hospital/physician-owned ASC safe harbor. Each safe harbor imposes distinct requirements on the composition of the investor group, the qualification of investors as referring physicians, the relationship between investment returns and referral volume, and the facility's compliance with applicable state and federal ASC regulations.

The common requirements across all four ASC safe harbors include: each physician investor must be in a position to perform procedures at the ASC and must actually use the ASC for that purpose; investment terms must be offered on terms that are not related to the previous or expected volume of referrals or other business generated by the investor; investment returns must be proportional to investment and not based on referral volume; the ASC must not loan funds to or guarantee loans for investors in a position to make referrals; and the ASC must not condition an investor's receipt of investment returns on any requirement to refer patients to the ASC. For the surgeon-owned model, all investors must be surgeons who regularly perform procedures at the ASC and derive at least one-third of their medical practice income from procedures performed there. For the multi-specialty model, the ASC must derive at least one-third of its annual revenue from procedures performed by physician investors.

In M&A transactions involving ASC acquisitions, diligence must assess whether the existing physician ownership structure satisfies the applicable safe harbor. Common deficiencies include physician investors who do not meet the income-from-procedures threshold, return distribution formulas that correlate with referral volume, undocumented loan arrangements between the ASC and physician investors, and informal preferences for investing physicians in procedure scheduling. The Stark Law also contains a specific exception for ownership interests in ASCs (42 CFR 411.356(c)(3)) that must be analyzed separately. An ASC that fails either the Stark exception or the AKS safe harbor analysis carries compliance exposure that must be disclosed, indemnified, or remediated as part of the transaction structure.

2020 Sprint Final Rule: Value-Based Arrangements and Stark Modifications

CMS and OIG published coordinated final rules in November 2020, known collectively as the Sprint regulations, that implemented significant modifications to the Stark Law and AKS frameworks to accommodate value-based care arrangements. The Sprint rulemaking recognized that the traditional Stark and AKS frameworks, designed to address fee-for-service referral incentives, created friction for arrangements designed to improve care quality and reduce costs through coordinated care models. The final rules created new regulatory pathways for value-based arrangements while retaining the core prohibitions that protect against improper financial incentives.

CMS added three new Stark exceptions for value-based arrangements (42 CFR 411.357(aa)). The full financial risk exception protects arrangements where the physician and the entity are both at full financial risk for the cost of care. The meaningful downside financial risk exception protects arrangements where the physician bears at least 10 percent of the downside financial risk for failure to achieve the value-based purpose. The value-based arrangements exception, the broadest of the three, protects arrangements that meet certain safeguards but do not require the physician to bear downside financial risk. All three exceptions require that the arrangement be part of a value-based enterprise, that the compensation be for the purpose of achieving a defined value-based purpose, and that the compensation not be conditioned on referrals to a particular provider or the reduction or limitation of medically necessary services.

OIG added corresponding AKS safe harbors for value-based arrangements (42 CFR 1001.952(ee) and (ff)) in the 2020 Sprint rule. These safe harbors protect remuneration exchanged between participants in value-based arrangements that are directed at improving the quality, effectiveness, or efficiency of care for a target patient population. The OIG also formalized a safe harbor for care coordination arrangements (42 CFR 1001.952(gg)), which protects in-kind remuneration provided for the purpose of improving care coordination and quality for the target population, provided the remuneration is not a tool for inducing referrals and does not result in net financial gain to the physician beyond the value of the remuneration received. In M&A diligence, the Sprint rules are relevant because targets operating accountable care organizations, bundled payment programs, or risk-sharing arrangements may have physician financial relationships that fall outside traditional Stark exceptions and AKS safe harbors but within the new value-based frameworks.

Diligence Protocols for Physician Compensation Arrangements

Stark and AKS diligence in a healthcare acquisition requires a systematic review of every financial relationship between the target entity and any physician who refers patients to the target for DHS. The scope of this review extends beyond formal employment agreements to include all compensation arrangements of any type: independent contractor agreements, medical director agreements, on-call coverage agreements, co-management agreements, equipment leases, office space leases, consulting agreements, research agreements, speaking honoraria, and any other arrangement under which a physician or a physician's immediate family member receives remuneration from the entity.

The diligence protocol for each arrangement involves a seven-step analysis. First, identify whether the physician is in a position to refer patients to the entity for DHS. Second, determine the nature of the financial relationship (compensation arrangement, ownership interest, or both). Third, identify the applicable Stark exception and confirm that all technical requirements of that exception are satisfied. Fourth, identify the applicable AKS safe harbor and confirm that all requirements are met. Fifth, assess whether compensation is consistent with contemporaneous FMV documentation, including the methodology used, the surveys relied upon, and the qualifications of any independent valuation firm. Sixth, evaluate commercial reasonableness by assessing whether the arrangement serves a legitimate business purpose independent of the referral relationship. Seventh, review compliance with the written agreement requirements, including signatures, term provisions, service specifications, and termination provisions.

The diligence work product should generate a compliance matrix that maps each arrangement to its applicable exception and safe harbor, identifies any compliance gaps, and quantifies the exposure associated with those gaps. Exposure quantification typically involves calculating the aggregate Medicare payments received for DHS furnished pursuant to prohibited referrals over the relevant look-back period (typically three to six years, based on the applicable statute of limitations), which represents the theoretical repayment obligation. This quantification informs the indemnification and escrow structure for compliance risk in the purchase agreement. Diligence should also review any prior government investigations, CMS audit activity, or zone program integrity contractor (ZPIC) audits involving the target's physician compensation practices.

SRDP, OIG Self-Disclosure Protocol, Advisory Opinions, Indemnification, and Integration Remediation

When diligence identifies actual or potential Stark violations, the acquirer must evaluate whether voluntary self-disclosure through the CMS Self-Referral Disclosure Protocol is appropriate. The SRDP, established under Section 6409 of the Affordable Care Act, allows providers to voluntarily report Stark violations to CMS and to negotiate a settlement that resolves the repayment obligation associated with prohibited referrals. CMS has historically settled SRDP submissions at amounts significantly below the full theoretical repayment exposure calculated under the prohibited referrals framework, providing a meaningful incentive for voluntary disclosure. The decision to disclose through the SRDP should be made in consultation with healthcare regulatory counsel, because the submission triggers a government review process that creates its own procedural obligations and strategic considerations.

When diligence identifies potential AKS violations, the OIG Self-Disclosure Protocol is the parallel mechanism for voluntary disclosure to the OIG. The OIG SDP allows entities to report potential AKS violations, Civil Monetary Penalties Law violations, and exclusion-related issues to the OIG and to negotiate a settlement resolving the government's civil monetary penalty exposure. OIG SDP settlements typically involve a civil monetary penalty component, a compliance program component, and in some cases a Corporate Integrity Agreement. As with the SRDP, the decision to proceed with an OIG SDP submission requires careful strategic analysis, because it initiates a government review process and creates disclosure obligations that affect transaction timing and structure.

In transactions where compliance exposure is identified but self-disclosure is not yet determined to be necessary or appropriate, the purchase agreement should address the exposure through indemnification provisions and escrow arrangements. A seller indemnity for pre-closing Stark and AKS violations, backed by an escrow funded at closing, provides the acquirer with a defined remedy for compliance findings that emerge post-closing. The escrow amount should be calibrated to the exposure quantification from diligence, with appropriate risk-weighting for the probability that a violation will be identified and pursued by the government. Integration remediation planning should include a detailed timeline for bringing all physician compensation arrangements into full compliance with Stark and AKS requirements, including renegotiation of non-compliant agreements, updated FMV analyses, revised written agreement terms, and enhanced compliance monitoring protocols.

Frequently Asked Questions