Ambulance Diversion: When Can a Hospital Legally Turn Away an Ambulance? (42 CFR § 489.24(b))

Ambulance diversion places hospitals and affiliated clinics at significant EMTALA risk because EMTALA generally prohibits refusing an individual who presents to the emergency department or arrives by ambulance. Under 42 CFR 489.24(b), the hospital must accept the patient unless the ambulance is operating under a community-wide diversion plan based solely on capacity or redirecting voluntarily. While diversion is common during high-volume surges, CMS considers improper diversion a serious EMTALA violation. For small practices that coordinate call coverage, see diverted patients, or participate in hospital-affiliated provider-based departments, it is essential to understand how diversion decisions are documented, defended, and evaluated. This article outlines legal boundaries for diversion, how CMS investigates complaints, and the precise evidence small practices should maintain to avoid contributing to diversion-related EMTALA findings.

Ambulance diversion occurs when a hospital temporarily signals to EMS agencies that it cannot safely accept new ambulance arrivals due to capacity constraints. EMTALA does not explicitly prohibit diversion, but it restricts when hospitals may rely on it. Even during diversion, if an ambulance arrives on hospital property or if EMS insists on bringing the patient in, 42 CFR 489.24(b) requires the hospital to provide a medical screening examination.

For small clinics working with hospitals, incorrect advice to EMS, inconsistent documentation, or incomplete communication logs may trigger or exacerbate EMTALA investigations. Ensuring that diversion decisions are valid, well documented, and consistently communicated protects the entire care network.

Understanding Legal Framework & Scope Under 42 CFR 489.24 b

1. EMTALA’s Core Rule for Ambulances

Once an ambulance arrives on hospital property, EMTALA obligations attach immediately under 42 CFR 489.24(b). The hospital must:

• Provide a medical screening examination, and

• Provide necessary stabilizing treatment or an appropriate transfer.

2. When Diversion Is Allowed

Diversion is legally defensible only under very narrow circumstances:

• The hospital is operating under a bona fide, community-wide diversion protocol, not a hospital-specific preference.

• The ambulance has not yet arrived on hospital property.

• The ambulance crew voluntarily agrees to divert.

• The diversion reason is limited to capacity, not payer status, diagnosis, or perceived complexity.

3. When Diversion Becomes an EMTALA Violation

Diversion is unlawful if:

• The hospital selectively diverts based on insurance or diagnosis.

• The hospital tells EMS not to come even though capacity exists.

• Diversion is declared for convenience or resource preference.

• The ambulance arrives despite diversion and is still turned away.

• A clinic or off-campus department gives misleading direction leading to the diversion.

4. State Flexibility vs Federal Baseline

States may establish regional diversion protocols, but EMTALA remains the binding federal standard. A state-approved diversion plan does not excuse a violation if the hospital improperly refuses a patient under 42 CFR 489.24(b).

Understanding these legal boundaries helps small practices ensure their communication does not contribute to unlawful diversion outcomes.

CMS is responsible for EMTALA enforcement, while state survey agencies perform field investigations. OIG may impose civil monetary penalties when unlawful diversion results in patient harm, delay, or discriminatory treatment.

Most Common Triggers for Diversion-Related EMTALA Surveys

• A diverted patient experiences clinical deterioration or death.

• EMS files a complaint based on improper redirection.

• Diversion status logs contradict staff statements.

• Hospitals divert ambulances despite having open beds.

• Communication between EMS and hospital is mis documented or inconsistent.

• A small affiliated clinic provides direction that EMS interprets as hospital refusal.

Surveyors focus on:

• Bed-capacity documentation at the time of diversion.

• Staffing levels and resource availability.

• Whether the hospital followed a community-wide protocol.

• The consistency of diversion logs, call recordings, and witness accounts.

These actions help small practices and hospital-affiliated providers ensure that their communication and documentation support lawful diversion under 42 CFR 489.24(b) and do not inadvertently create EMTALA risk.

1. Maintain an ED Capacity & Diversion Status Log

CMS evaluates diversion legitimacy by examining documentation of actual capacity.

• Implementation: Track beds, staff levels, critical resources, and diversion start/stop times.

• Evidence: A time-stamped log showing capacity constraints consistent with diversion decisions.

• Low-cost option: Shared spreadsheet updated by charge staff.

2. Confirm Diversion Status Before Giving EMS Guidance

Small clinics affiliated with hospitals must avoid giving incorrect direction.

• Implementation: Require staff to verify diversion status through a designated central contact or dashboard before speaking with EMS.

• Evidence: Documentation of verification timestamp.

• Low-cost option: A diversion verification script posted at phones.

3. Document the Reason for Diversion Clearly

Surveyors assess whether diversion was due to capacity, not discriminatory motives.

• Implementation: Record census data, staffing shortages, resource limitations, and other objective indicators.

• Evidence: Written justification tied to diversion timeline.

• Low-cost option: Standardized diversion justification form.

4. Maintain Thorough Communication Logs With EMS

In diversion cases, EMS communications become central evidence.

• Implementation: Note time of EMS contact, diversion status given, and any follow-up instructions.

• Evidence: Complete call log with no gaps.

• Low-cost option: Centralized EMS call-log sheet.

5. Prepare for Ambulances That Ignore Diversion

If an ambulance arrives anyway, EMTALA applies fully.

• Implementation: Adopt a standing policy to treat any patient who reaches hospital property.

• Evidence: Records showing full medical screening and stabilizing treatment.

• Low-cost option: Brief protocol posted in triage.

6. Ensure Off-Campus Departments Do Not Mislead EMS

Provider-based clinics may accidentally direct ambulances incorrectly.

• Implementation: Train staff to avoid statements implying hospital status or capacity without verification.

• Evidence: Staff scripts clarifying that diversion decisions must come from ED leadership.

• Low-cost option: Placard: “This site cannot authorize or deny ambulance arrival.”

7. Conduct Diversion Event Reconstruction After Incidents

CMS often requests a minute-by-minute timeline.

• Implementation: Combine logs, call notes, staffing records, and bed counts.

• Evidence: A unified timeline that corroborates staff statements.

• Low-cost option: Diversion reconstruction template.

These operational steps make diversion defensible and avoid conflicts with 42 CFR 489.24(b) when the facility’s status is reviewed by CMS.

Case Study

During a high-volume evening surge, a hospital declared diversion under a regional EMS protocol because all monitored ED beds were full, and staffing ratios exceeded safety thresholds. Ten minutes later, an affiliated off-campus clinic received a call from EMS asking whether the hospital could accept a cardiac patient. A staff member at the clinic, unaware of the diversion status, mistakenly said, “They should be open.” EMS proceeded toward the hospital.

Upon arrival, the hospital insisted that it was on diversion and directed EMS elsewhere. The patient suffered a cardiac arrest during the additional transport time.

CMS Findings

• Diversion logs showed the hospital was legitimately on capacity diversion.

• Staff at the affiliated clinic provided incorrect information to EMS.

• EMS interpreted the clinic’s statement as hospital authorization.

• The hospital’s refusal upon arrival violated 42 CFR 489.24(b) because the ambulance reached hospital property.

• Inconsistent communication created an appearance of selective redirection.

Outcome

• CMS cited the hospital for refusing an ambulance that had arrived on its property.

• OIG pursued civil monetary penalties.

• The off-campus clinic was required to implement strict communication controls and diversion-verification protocols to prevent recurrence.

How the Operational Playbook Would Have Helped

• Verification protocols,

• A diversion dashboard,

• A strict “no guidance unless verified” script, and

• Reconstruction tools
   would have prevented miscommunication and shown that the clinic acted in accordance with EMTALA expectations.

Common Audit Pitfalls to Avoid Under 42 CFR 489.24 b

Ambulance diversion often generates EMTALA citations when documentation or communication is incomplete. Below are pitfalls specific to diversion cases.

• Declaring diversion without capacity evidence, suggesting discriminatory motivation.

• Turning away an ambulance that arrives on property, which is always unlawful under EMTALA.

• Off-campus staff giving unverified EMS direction, creating inconsistent evidence.

• Missing call logs, making it impossible to prove consistent messaging.

• Failure to reconcile diversion start and stop times, which undermines diversion legitimacy.

• Selective acceptance of certain patients, raising concerns about insurance-based or diagnosis-based diversion.

Avoiding these pitfalls strengthens compliance and ensures defensible diversion practices under 42 CFR 489.24(b).

Strong diversion governance ensures consistency across all sites connected to the hospital. Leadership should maintain real-time visibility into bed capacity, enforce strict rules prohibiting unverified communication with EMS, and conduct regular drills simulating diversion scenarios. Training should focus on clarity, accuracy, and documentation. Metrics such as diversion duration, communication accuracy, and log completeness help identify ongoing risks.

Ambulance diversion is a rare but essential operational tool during periods of high strain. However, EMTALA strictly limits the circumstances under which hospitals may divert ambulances. By aligning actions with 42 CFR 489.24(b), and documenting every decision across hospitals and affiliated clinics, small practices help build a defensible compliance posture. Miscommunication is the most common risk; documentation is the strongest protection.

Next Actions

1. Deploy the ED Capacity & Diversion Status Log.

2. Train all staff to verify official diversion status before speaking to EMS.

3. Maintain structured call logs for every EMS contact.

4. Reconstruct diversion timelines after any disputed event.

5. Audit diversion records monthly to ensure accuracy and consistency.

Recommended compliance tool

A shared “Medicare Plan Interaction” log and policy folder on your existing network or EHR, used to store scripts, training records, and any sponsor correspondence about beneficiary communications.

Advice:

Before the next open enrollment, walk through your clinic as an auditor would and remove or rewrite anything that could be interpreted as recommending one Part D plan over another.

• EMTALA Regulations – 42 CFR 489.24
  

• CMS State Operations Manual, Appendix V – EMTALA Guidelines
  

• Emergency Medical Treatment and Labor Act (42 USC 1395dd)
  

• Federal Register EMTALA Interpretive Guidance
  

• HHS Office of Inspector General – Civil Monetary Penalties Law Guidance