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CO-117 Denial Code: Transport Beyond Closest Facility

CO-117 means the payer covers transportation only to the closest facility able to provide the necessary care. The patient was taken farther, so the payer denied the transport or reduced it, usually by limiting mileage to the distance to the nearest appropriate facility.

Quick facts

Code
CO-117 (CARC 117)
Status
Active In use since January 1, 1995; last modified September 30, 2007.
Code set
Claim Adjustment Reason Codes (CARC)
Group codes
  • CO (Contractual Obligation): The provider absorbs the reduction, typically because the destination choice was not documented as necessary. It generally cannot be billed to the patient under CO.
  • PR (Patient Responsibility): The patient chose a farther facility for personal reasons and agreed in advance to pay the excess. Confirm payer rules and any signed notice before billing.
Official description
Transportation is only covered to the closest facility that can provide the necessary care.
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What CO-117 means

CARC 117 says transportation is only covered to the closest facility that can provide the necessary care. It applies to ambulance and other covered transportation. The payer compared the destination with nearer facilities and concluded a closer one could have treated the patient. It then denies the transport or cuts back payment, most often the mileage beyond the nearest appropriate facility.

The key word is “appropriate.” A trauma patient taken to a trauma center, a stroke patient taken to a stroke-capable hospital, or a patient diverted because the nearest emergency department was closed may all justify a longer trip. What matters is whether the run report shows it.

Common causes

  • Transport to a patient’s preferred hospital when a closer facility could provide the same care.
  • Run reports that do not state why the destination was chosen.
  • Hospital diversion, bed availability, or specialty needs not documented.
  • Mileage reported from the wrong starting point or to the wrong destination.
  • Interfacility transports where the reason the sending facility could not provide care is missing.

How to fix it

  1. Review the run report for the destination decision: patient condition, capabilities needed, diversion status, and any medical direction.
  2. Check mileage reported in box 24G against the pickup and drop-off addresses. Correct errors with a corrected claim (resubmission code 7 in box 22).
  3. Appeal with documentation showing that nearer facilities could not provide the needed care.
  4. If the destination was a patient preference, check whether the patient signed an advance notice accepting the extra cost. If so and the payer allows it, bill the patient the excess. Otherwise, write it off.
  5. Contact the payer if you believe its closest-facility determination used the wrong facility list or distances.

How to prevent it

  • Require crews to document the destination rationale in every run report.
  • Record diversion and specialty center status at the time of transport.
  • Validate loaded mileage from pickup to destination before billing.
  • Use advance notices for non-emergency transports to patient-chosen facilities that are farther away.
  • For broader patterns, see medical claim denials and their preventable causes.

Specialty notes

This is an ambulance-focused code. Emergency transports need clear documentation of the patient’s condition and the capabilities required. Non-emergency and interfacility transports face even closer scrutiny of why a particular destination was necessary.

Remark codes that may appear with CO-117

  • N157 (Transportation to/from this destination is not covered.): Transportation to or from this destination is not covered.
  • N745 (Missing Ambulance Report.): The ambulance report is missing, so the payer could not confirm why the destination was chosen.
  • N746 (Incomplete/invalid Ambulance Report.): The ambulance report is incomplete or invalid.
  • CO-50 (These are non-covered services because this is not deemed a 'medical necessity' by the payer.): Medical necessity denial, common for ambulance transport level or need.
  • CO-58 (Treatment was deemed by the payer to have been rendered in an inappropriate or invalid place of service.): Treatment deemed to be in an inappropriate place of service.
  • CO-40 (Charges do not meet qualifications for emergent/urgent care.): Charges do not meet qualifications for emergent or urgent care.
  • CO-151 (Payment adjusted because the payer deems the information submitted does not support this many/frequency of services.): Payment adjusted because the information does not support the number or frequency of services, including mileage units.

CO-117 FAQ

What counts as the closest appropriate facility?

Generally, the nearest facility that has the staff, equipment, and services the patient needs at that moment. A farther facility can be appropriate when closer ones cannot provide that care or lack capacity, if documented.

Will the payer pay any mileage after CO-117?

Often the payer pays mileage only up to the distance to the nearest appropriate facility. The rest is adjusted. Payer policies vary.

How do I appeal a CO-117?

Send the run report showing why nearer facilities were not appropriate, such as specialty care needed, diversion status, or bed availability, and any instructions from medical control.