ED Facility Level Coding Guidelines


A part of the Federal Balanced Budget Act of 1997 required HCFA (now CMS) to create a new Medicare "Outpatient Prospective Payment System" (OPPS) for hospital outpatient services; analogous to the Medicare prospective payment system for hospital inpatients known as "Diagnosis Related Groups" or DRG's. APC's or "Ambulatory Payment Classifications" are the government's method of paying for facility outpatient services for the Medicare program. APC's apply only to hospitals, and have no impact on physician payments under the Medicare Physician Fee Schedule. For further information about APC's, see the Frequently Asked Questions on the ACEP website.  

Facility coding guidelines are inherently different from professional coding guidelines. Facility coding reflects the volume and intensity of resources utilized by the facility to provide patient care, whereas professional codes are determined based on the complexity and intensity of provider performed work and include the cognitive effort expended by the provider.  As such, there is no definitive strong correlation between facility and professional coding and thus no rational basis for the application of one set of derived codes, either facility or professional, to the determination of the other on a case-by-case basis.  

In 2011 OPPS, CMS restated its position on "Triage-only" visits confirming that it does not specify the type of staff who may provide services.  "A hospital may bill a visit code based on the hospital's own coding guidelines which must reasonably relate the intensity of hospital resources to different levels of HCPCS codes.  Services furnished must be medically necessary and documented."  

However, in a 2012 Facility FAQ, CMS indicated that Hospital outpatient therapeutic services and supplies (including visits) must be furnished incident to a physician's service and under the order of a physician or other qualified practitioner.  Services provided by a nurse in response to a standing order do not satisfy this requirement.  Since diagnostic services do not need to meet the requirements for incident to services, they may be coded even if the patient were to leave without being seen by the physician.  

At this point, there is no national standard for hospital assignment of E&M code levels for outpatient services in clinics and the Emergency Department (ED). CMS requires each hospital to establish its own facility billing guidelines.  Further, OPPS lists eleven criteria that must be met for facility billing guidelines.  (see APC FAQ)  Facility billing guidelines should be designed to reasonably relate the intensity of hospital services to the different levels of effort represented by the codes. Coding guidelines should be based on facility resources, should be clear to facilitate accurate payments, should only require documentation that is clinically necessary for patient care, and should not facilitate upcoding or gaming.  For further information, see the 2009 CMS Final Rule for facility billing. A summary of the OPPS rule is available on the ACEP website.  

ACEP believes the facility billing guidelines outlined below are consistent with the OPPS principles and provides them as one possible set of guidelines.  Facilities using the guidelines should ensure they are appropriate for use and reflect the salient circumstances of their institution.  Some facilities have found it helpful to adapt the guidelines to the particular needs of their institution.  

Instructions for Use

The ACEP facility coding model provides an easy to use methodology for assigning visit levels in an Emergency Department (ED). There are three columns in the guidelines. The far left column indicates the facility codes and corresponding APC levels which are justified by the "Possible Interventions" listed in the middle column. The far right column labeled "Potential Symptoms/Examples which Support the Interventions" is simply used as an aid to the coder in determining which interventions most likely correspond with a given facility code/APC level. This far right column of "Potential Symptoms/Examples" is not used to determine the appropriate facility code/APC level. The determination of the appropriate facility code/APC level is based solely on the "Possible Interventions" listed in the middle column. The "Possible Interventions" refer to interventions on the part of the nursing and ancillary staff in the Emergency Department and not to interventions by the emergency physicians.  “Possible Interventions" includes some procedure examples which might be billed separately by the facility.  The procedures listed serve as a proxy, qualifying the typical intensity of facility services provided for patients requiring them.  Such procedure examples are not intended to substitute for or duplicate labor, time or supplies included in separately billable procedures.  Levels of "Discharge Instructions" are defined in the last section of these guidelines.  

The appropriate facility code/APC level is determined by the interventions (of nursing and ancillary ED staff) as listed in the middle column marked "Possible Interventions". If a given "Possible Intervention" is listed in a section assigned to a specific facility code level, and if no other interventions are provided that fall into a higher facility code level, then the facility code level corresponding to that specific "Possible Intervention" is selected as the appropriate "facility code/APC level". Within a given facility code/APC level, there may be multiple "Possible Interventions" provided, all of which fall into the same facility code/APC level. Whether there is a single "Possible Intervention" or multiple "Possible Interventions"-all of which fall into the same facility code/APC level-the appropriate facility code/APC level to be assigned remains the same. In other words, whether only a single "Possible Intervention" listed at a given facility code level is present or if multiple or all "Possible Interventions" assigned to that facility code level are present-the facility code/APC level is still the same.  

In the "Possible Interventions" column, the first sentence states, "Could include interventions from previous (lower) levels, plus any of:" This simply means, for example, that if the highest facility code/APC level achieved by any "Possible Intervention" is a facility code 99283 and APC level 614, then the appropriate facility code to assign is a 99283. The presence of "Possible Interventions" from levels 99281 and/or 99282 in addition to the "Possible Intervention" listed in the 99283 section has no effect on the facility code level assigned. The facility code level assigned is always the highest level at which a minimum of one "Possible Intervention" is found.

An example of correct usage of this "Guideline" follows:

Example # 1

A 48 year old woman with a prior history of a myocardial infarction and atrial fibrillation comes to the emergency department complaining of pelvic pain. She receives an initial assessment by the ED nurse; she also has tests performed by the ED staff consisting of a stool hemoccult test and a urine dipstick test. She has a saline lock inserted by the ED nurse and subsequently has blood drawn through that IV site, and blood is sent to the Laboratory for several tests. The urine specimen was obtained following the insertion of a Foley catheter by the ED nurse. The patient is examined by the ED physician, including the performance of a pelvic examination (the ED nurse is in attendance during the pelvic exam). The patient is also prepared and sent to Radiology for the performance of a pelvic ultrasound examination. Transport to the Radiology Department is provided by Emergency Department staff, and the patient is monitored (cardiac monitor) during transport and the accomplishment of the pelvic ultrasound. Following the return of all tests, the ED physician diagnoses the patient with a ruptured ovarian cyst, prescribes analgesics, instructs the patient to follow-up the following day with her OB-GYN specialist, and instructs her to rest at home for the next 48 hours. The nurse provides discharge instructions which are "Complex" (See definitions for levels of nursing instructions in the last section of these guidelines). The coder then uses the "Guidelines" as follows: First the coder looks in the far right hand column for "Pelvic Pain". This symptom is not listed; however "Abdominal Pain" is listed at both the 99284 and 99285 levels. Therefore, the coder looks at the 99285 level for any "Possible Intervention" provided by the nursing and ancillary ED staff at the 99285 level. Under the 99285 level of "Possible Interventions" are two of the interventions provided to this patient:

    A. Monitoring vital signs of patient during in-hospital transport and testing
    B. Discussion of Discharge Instructions "Complex"

The appropriate level of "Facility code" for services provided to this ED patient is therefore 99285 and the corresponding appropriate APC level is 616.

Example #2

A 66 year old woman who has been in excellent health and who takes no prescription medications comes to the Emergency Department complaining of low grade fever, dysuria and urinary frequency. The ED nurse assesses her and performs a urine dipstick examination on a urine specimen obtained by an "in and out" Foley catheterization-on the order of the ED physician. The ED physician examines the patient, the only positive findings are a temperature of 101 degrees Fahrenheit (oral) and moderate suprapubic tenderness. The urine dipstick examination is positive for leukocyte esterase and for nitrites but is otherwise negative. The physician diagnoses "Acute Cystitis" and prescribes antibiotics and analgesics. The nurse gives the patient one tablet of Pyridium and one tablet of Sulfamethoxazole/Trimethoprim which the patient takes while in the ED. The ED nurse provides discharge instructions of "Moderate Complexity". The patient returns home.

The coder looks in the far right column under "Potential Symptoms/Examples" and finds two items applicable to this patient:

    A. Medical conditions requiring prescription drug management
    B. Fever which responds to antipyretics

The coder thus looks for "Possible Interventions at the 99283 level-which corresponds to the "Potential Symptoms/Examples" which are present in regard to this patient. The coder finds the following interventions which were provided to this patient:

    A. Prescription medications administered PO
    B. Foley catheters; In & Out caths
    C. Discussion of discharge instructions (Moderate Complexity)

The coder then looks at facility code levels 99284 and 99285 to determine if any interventions falling within those levels were provided. The coder determines that the highest facility code level achieved by any intervention provided to this patient is intervention at the 99283 level. Thus, the coder assigns facility code 99283 (APC 614) as the appropriate "Facility Code Level". 

Critical Care
Facility code 99291 - APC Level 617

The assignment of the Critical Care code 99291 likewise follows the same instructions applicable to the five E&M codes 99281-99285. There is a 30 minute time requirement for facility billing of critical care.

The administration and monitoring of IV vasoactive medications (such as adenosine, dopamine, labetolol, metoprolol, nitroglycerin, norepinephrine, sodium nitroprusside, etc) is indicative of critical care.


EMS brings in a 68 year old man who is suffering grand mal convulsions, with only brief interludes of from one to three minutes between convulsions. He undergoes a multiplicity of diagnostic tests, receives 2 mg of Ativan IV followed by an IV infusion of one gram of Dilantin over one hour. His blood pressure is 240/140 and he receives an IV infusion of sodium nitroprusside which brings his pressure down to180/110.  A C-T scan reveals an acute intracerebral hemorrhage which is fairly small and which has not yet resulted in any mid-line shift of the cerebral hemispheres. He is transferred to another hospital (to the on-call neurosurgeon) for numerous reasons, including the family's wishes and the fact that the only neurosurgeon in town is presently in surgery at the "other hospital". 45 minutes of Critical Care is documented.

The coder looks under "Potential Symptoms/Examples" and finds "Status-Asthmaticus, Epilepticus" as well as "Cerebral Hemorrhage of any type" listed under the "Critical Care" section. The coder identifies documentation that the patient received IV drips of Dilantin and sodium nitroprusside and then finds the intervention of "Multiple parenteral medications requiring constant monitoring" under the "Critical Care" guideline. With 45 minutes of Critical Care time documented and since only a single intervention listed under the "Possible Interventions" applicable to "Critical care" is necessary in order to assign facility code 99291, the coder assigns Critical Care code 99291 (APC 617). 

Definitions for Discharge Instructions

Straightforward: Self-limited condition with no meds or home treatment required, signs and symptoms of wound infection explained, return to ED if problems develop

Simple: OTC medications or treatment, simple dressing changes; patient demonstrates understanding quickly and easily

Moderate: Head injury instructions, crutch training, bending, lifting, weight-bearing limitations, prescription medication with review of side effects and potential adverse reactions; patient may have questions, but otherwise demonstrates adequate understanding of instructions either verbally or by demonstration

Complex: Multiple prescription medications and/or home therapies with review of side effects and potential adverse reactions; diabetic, seizure or asthma teaching in compromised or non-compliant patients; patient/caregiver may demonstrate difficulty understanding instructions and may require additional directions to support compliance with prescribed treatment. 


The American College of Emergency Physicians (ACEP) has developed these ED Facility Level Coding Guidelines (Guidelines) for informational purposes only.   These Guidelines have been developed by sources believed to be knowledgeable in their fields and conveys their editorial opinion behind the various codes.  However, neither ACEP nor its committee members, authors or editors warrant that the information contained in the Guidelines is in every respect accurate and/or complete.   ACEP, its committee members, authors and editors assume no responsibility for, and expressly disclaim liability for, damages of any kind arising out of or relating to the use of, reference to, or reliance on the Guidelines.   These Guidelines are not intended to be construed or to serve as the definitive reference for CMS OPPS coding.  OPPS coding is determined on the basis of all the facts and circumstances involved in each individual case and is subject to change as patterns of practice evolve.   Payment policies for OPPS are determined by CMS.  Therefore, any specific payment related questions or issues must be directed to CMS. 

   Facility Charge Assignment  
 Level Possible Interventions1 Potential Symptoms/Examples which support the Interventions
CPT 99281
Type A: APC 609Type B: APC 626HCPCS: G0380 
Initial Assessment
No medication or treatments
Rx refill only, asymptomatic
Note for Work or School
Wound recheck
Booster or follow up immunization, no acute injury
Dressing changes (uncomplicated)
Suture removal (uncomplicated)
Discussion of Discharge
Instructions (Straightforward)
Insect bite (uncomplicated)
Read Tb test
CPT 99282
 Type A: APC 613Type B: APC 627HCPCS: G0381 
Could include interventions from previous levels, plus any of:
Tests by ED Staff (Urine dip, stool hemoccult,  Accucheck or Dextrostix)
Visual Acuity (Snellen)
Obtain clean catch urine
Apply ace wrap or sling
Prep or assist w/ procedures such as: minor laceration repair, I&D of simple abscess, etc.
Discussion of Discharge Instructions (Simple)
Localized skin rash, lesion, sunburn
Minor viral infection
Eye discharge- painless
Ear Pain
Urinary frequency without fever
Simple trauma (with no X-rays) 
CPT 99283
 Type A: APC 614Type B: APC 628HCPCS: G0382 
Could include interventions from previous levels, plus any of:
Receipt of EMS/Ambulance patient
Heparin/saline lock
(1) Nebulizer treatment
Preparation for lab tests described in CPT (80048-87999 codes)Preparation for EKG
Preparation for plain X-rays of only 1 area (hand, shoulder, pelvis, etc.)
Prescription medications administered PO
Foley catheters;  In & Out caths
C-Spine precautions
Fluorescein stain
Emesis/ Incontinence care
Prep or assist w/procedures such as: joint aspiration/injection, simple fracture care etc.
Mental Health-anxious, simple treatment
Routine psych medical clearance
Limited social worker intervention
Post mortem care
Direct Admit via ED
Discussion of Discharge Instructions (Moderate Complexity)
Minor trauma (with potential complicating factors)
Medical conditions requiring prescription drug management
Fever which responds to antipyretics     
Headache - Hx of, no serial exam
Head injury- without neurologic symptoms
Eye pain         
Mild dyspnea -not requiring oxygen
CPT 99284
 Type A: APC 615Type B: APC 629HCPCS: G0383 
Could include interventions from previous levels, plus any of:
Preparation for 2 diagnostic tests2: (Labs, EKG, X-ray)
Prep for plain X-ray (multiple body areas):
C-spine & foot, shoulder & pelvis
Prep for special imaging study (CT, MRI, Ultrasound,VQ scans)
Cardiac Monitoring (2) Nebulizer treatments
Port-a-cath  venous access                                         Administration and Monitoring of infusions or parenteral medications (IV, IM, IO, SC) NG/PEG
Tube Placement/Replacement Multiple reassessments
Prep or assist w/procedures such as: eye irrigation with Morgan lens, bladder irrigation with 3-way foley, pelvic exam, etc.
Sexual Assault Exam w/ out specimen collection Psychotic patient; not suicidal
Discussion of Discharge Instructions (Complex)
Blunt/ penetrating trauma- with limited diagnostic testing
Headache with nausea/ vomiting
Dehydration requiring treatment
Vomiting requiring treatment
Dyspnea requiring oxygen
Respiratory illness relieved with (2) nebulizer treatments
Chest Pain--with limited diagnostic testing
Abdominal Pain - with limited diagnostic testing
Non-menstrual vaginal bleeding
Neurologic symptoms - with limited diagnostic testing
CPT 99285
 Type A: APC 616Type B: APC 630  HCPCS: G0384 
Could include interventions from previous levels, plus any of:
Requires frequent monitoring of multiple vital signs (ie. 02 sat, BP, cardiac rhythm, respiratory rate)
Preparation for ≥ 3 diagnostic tests2: (Labs, EKG, X-ray)
Prep for special imaging study (CT, MRI, Ultrasound, VQ scan) combined with multiple tests or parenteral medication or oral or IV contrast.
Administration of Blood Transfusion/Blood Products Oxygen via face mask or NRB Multiple Nebulizer Treatments: (3) or more (if nebulizer is continuous, each 20 minute period is considered treatment)
Moderate Sedation
Prep or assist with procedures such as: central line insertion, gastric lavage, LP, paracentesis,etc.
Cooling or heating blanket
Extended Social Worker intervention
Sexual Assault Exam w/ specimen collection by ED staff
Coordination of hospital admission/ transfer or change in living situation or site
Physical/Chemical Restraints;
Suicide Watch
Critical Care less than 30 minutes
Blunt/ penetrating trauma requiring multiple diagnostic tests
Systemic multi-system medical emergency requiring multiple diagnostics
Severe infections requiring IV/IM antibiotics
Uncontrolled DM
Severe burns
New-onset altered mental status
Headache (severe): CT and/or LP
Chest Pain--multiple diagnostic tests/treatments
Respiratory illness--relieved by (3) or more nebulizer treatments
Abdominal Pain--multiple diagnostic tests/treatments
Major musculoskeletal injury
Acute peripheral vascular compromise of extremities
Neurologic symptoms - multiple diagnostic tests/treatments
Toxic ingestions                Mental health problem - suicidal/ homicidal
Critical Care - Critical Care can be coded based upon either the provision of any of the listed possible interventions or by satisfying the Critical Care definition. A minimum of 30 minutes of care must be provided. Critical Care Involves decision-making of high complexity to assess, manipulate, and support impairments of "one or more vital organ systems such that there is a high probability of imminent or life threatening deterioration in the patient's condition." This includes, but is not limited to, "the treatment or prevention of further deterioration of central nervous system failure, shock-like conditions, renal, hepatic, metabolic or respiratory failure, post-operative complications or overwhelming infection." Under OPPS, the time that can be reported as Critical Care is the time spent by a physician and/or hospital staff engaged in active face-to-face critical care of a critically ill or critically injured patient. If the physician and hospital staff or multiple hospital staff members are simultaneously engaged in this active face-to-face care, the time involved can only be counted once.
   Possible Interventions Potential Symptoms/Examples which support the Interventions
CPT 99291
Type A: APC 617

Could include interventions from previous levels, plus any or all of:
Multiple parenteral medications requiring constant monitoring
Provision of any of the following:
Major Trauma care/ multiple surgical consultants
Chest tube insertion
Major burn care
Treatment of active chest pain in ACS
Administration of IV vasoactive meds (see guidelines)
Defibrillation/ Cardioversion
Administration of ACLS Drugs in cardiac arrest
Therapeutic hypothermia                                                                    Bi-PAP/ CPAP
Endotracheal intubation
Ventilator management
Arterial line placement
Control of major hemorrhage
Pacemaker insertion through a Central Line
Delivery of baby
Multiple Trauma;  Head Injury with loss of consciousness
Burns threatening to life or limb
Coma of all etiologies   (except hypoglycemic)
Shock of all types: septic, cardiogenic, spinal, hypovolemic, anaphylactic
Drug Overdose impairing vital functions
Life-threatening hyper/ hypo-thermia
Thyroid Storm or Addisonian Crisis
Cerebral hemorrhage of any type
New-onset paralysis
Non-hemorrhagic strokes with vital function impairment
Status epilepticus
Acute Myocardial Infarction
Cardiac Arrythmia requiring emergency treatment
Aortic Dissection
Cardiac Tamponade
Aneurysm; thoracic or abdominal -- leaking or ruptured
Tension Pneumothorax
Acute respiratory failure, pulmonary edema, status asthmaticus
Pulmonary Embolus
Embolus of fat or amniotic fluid
Acute renal failure
Acute hepatic failure
Diabetic Ketoacidosis
Lactic Acidosis
DIC or other bleeding diatheses - hemophilia, ITP, TTP, leukemia, aplastic anemia
Major Envenomation by poisonous reptiles
CPT 99292 As above in additional 30 minute increments. Record the TOTAL critical care time. The first 30-74 minutes equal code 99291. If used, additional 30 minute increments (beyond the first 74 minutes) are coded 99292. Medicare does not pay for code 99292 because it is considered packaged into 99291; however the services should be reported as appropriate.
Critical Care with Trauma Team ActivationAPC 618G0390 In addition to 99291, designated trauma centers may report the Trauma Team Activation code G0390 when a trauma team was activated and all other trauma activation criteria are met.
Copyright © 2011 American College of Emergency Physicians

If you intend to use these guidelines, or an adaptation of them, Copyright permission can be requested here.   

If you have questions please contact the ACEP Reimbursement Department at 1-800-798-1822.  

Footnote 1:  Hospital outpatient therapeutic services and supplies (including visits) must be furnished incident to a physician's service and under the order of a physician or other qualified practitioner.  Services provided by a nurse in response to a standing order do not satisfy this requirement.  Since Diagnostic tests do not have to be performed incident to a physician service, they may be coded even if the patient were to leave without being seen by the physician.

Footnote 2:  As of 2021, CPT has clarified that a test is defined as a service that has a separate CPT code. Tests are imaging, laboratory, psychometric, or physiologic data. A clinical laboratory panel (eg, basic metabolic panel [80047]) is a single test. The differentiation between single or multiple unique tests is defined in accordance with the CPT code set.


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