Crystal's Coder Hub🛑 Modifier -73 — Discontinued Out-Patient Hospital/Ambulatory Surgery Center (ASC) Procedure Prior to the Administration of Anesthesia
Quick Reference
wRVU: N/A (Facility Only) | Global Period: N/A | Payment Impact: Reduces facility payment by 50%[1] | Physician Equivalent: Modifier -53
📋 Clinical Description
CPT Modifier 73 describes a scenario in the hospital outpatient department (HOPD) or Ambulatory Surgical Center (ASC) where a covered surgical or diagnostic procedure is cancelled due to extenuating circumstances or those that threaten the well-being of the patient[1]. The key differentiator for this modifier is that the cancellation occurs after the patient has been prepared and taken to the procedure room, but strictly before the administration of anesthesia (local, regional block, or general)[1].
This modifier applies only to facility charges, representing the resources expended by the ASC or hospital (e.g., room preparation, nursing time, surgical tray opening) prior to the cancellation[2].
This procedure may be performed in the following clinical contexts:
- Uncontrolled Hypertension or Arrhythmia — Discontinuing a procedure on the operating table prior to sedation due to a sudden, dangerous spike in blood pressure or heart rate.
- Equipment Failure — Discontinuing after patient positioning but before anesthesia due to catastrophic failure of essential surgical equipment (e.g., sterilization breach discovered late).
- Patient Condition Deterioration — Acute medical event in the procedure room (e.g., sudden respiratory distress, acute chest pain) before anesthesia induction.
🔬 Anatomical & Procedural Considerations
| Facility Type | Applicability | Key Notes |
|---|---|---|
| Ambulatory Surgical Center (ASC) | ✅ Applicable | Used to recoup costs for room preparation and staff time when the procedure is halted before anesthesia. Payment is reduced by 50%[1]. |
| Hospital Outpatient Dept (HOPD) | ✅ Applicable | Same rules apply as ASCs; represents outpatient facility resources expended[2]. |
| Physician Professional Services | ❌ Not Applicable | Physicians must use modifier -53 (Discontinued Procedure) for their professional claims, not -73[2]. |
Clinical Pearl
The timeline is the most critical element for an auditor. To successfully report modifier -73, the facility documentation must explicitly state two things: (1) the patient was physically present in the room where the procedure was to be performed, and (2) the cancellation occurred prior to the induction of anesthesia[1]. If anesthesia had already been administered, you must use modifier -74 instead[2].
✅ Procedure Includes
- Preparation of the operating/procedure room.
- Opening of surgical trays, supplies, and instruments.
- Pre-operative nursing care and patient transport to the procedure room.
- Patient positioning on the surgical table prior to anesthesia.
❌ Excludes / Do Not Report Together
| Code | Description | Relationship to -73 |
|---|---|---|
| -74 | Discontinued Procedure After Administration of Anesthesia | Mutually exclusive. Used by the facility if the procedure is stopped after anesthesia is administered or after the procedure has begun (e.g., scope inserted, incision made)[3]. |
| -53 | Discontinued Procedure (Physician) | Modifier -73 is for the facility fee. The operating physician reports modifier -53 on their professional claim to indicate the discontinued service[2]. |
| -52 | Reduced Services | Not used for cancelled procedures due to patient risk; used when a procedure is partially completed by design or choice. |
Bundling Alert — Elective Cancellations
Do not use modifier -73 if a procedure is cancelled prior to the patient being taken to the procedure room (e.g., patient cancelled in the preoperative holding area, or patient ate food before surgery). In those instances, the procedure cannot be billed by the facility at all.
💰 RVU & Reimbursement Profile
| Component | Value |
|---|---|
| Work RVU (wRVU) | N/A (Facility modifier only) |
| Payment Impact | 50% of the standard facility fee[1] |
| PC/TC Split | Facility Component (TC equivalent) |
Facility Billing Rules
🏷️ Modifier Reference
| Modifier | Name | When to Apply |
|---|---|---|
| -73 | Discontinued Outpatient Procedure Prior to Anesthesia | Applied by the ASC/HOPD when a procedure is stopped in the procedure room before anesthesia[1, 2]. |
| -74 | Discontinued Outpatient Procedure After Anesthesia | Applied by the ASC/HOPD when a procedure is stopped after anesthesia administration[2]. |
| -53 | Discontinued Procedure (Professional) | Applied by the physician on their professional (CMS-1500) claim when a procedure is stopped due to patient risk[2]. |
🩺 Common ICD-10-CM Pairings
Cancelled Procedure Grouping
| ICD-10 Code | Description | HCC? | Clinical Notes |
|---|---|---|---|
| Z53.09 | Procedure and treatment not carried out because of other contraindication | ❌ No | Often used as the secondary diagnosis to explain why the procedure was aborted. |
| Z53.8 | Procedure and treatment not carried out for other reasons | ❌ No | Used when the cancellation reason doesn’t fit a specific medical contraindication. |
Underlying Etiology / Complication Codes
| ICD-10 Code | Description | HCC? | Clinical Notes |
|---|---|---|---|
| R03.0 | Elevated blood-pressure reading, without diagnosis of hypertension | ❌ No | Use if the procedure was cancelled due to an acute hypertensive spike on the table. |
| R00.2 | Palpitations | ❌ No | Use if cancelled due to sudden arrhythmia or tachycardia prior to anesthesia. |
Coding Specificity Reminder
When billing a discontinued procedure, the primary diagnosis code should still be the reason the procedure was originally scheduled (e.g., screening for colon cancer, abdominal pain). The Z-code for the cancelled procedure and the R-code for the acute symptom causing the cancellation are billed as secondary diagnoses.
🏥 MS-DRG Considerations (Inpatient)
Inpatient Coding Reminder
Modifier -73 is used exclusively in the outpatient / ASC setting. It is never used for inpatient facility billing.
📝 Coding Examples
Example 1 — ASC: Discontinued Colonoscopy Prior to Sedation
Clinical Scenario: A patient presents to the ASC for a screening colonoscopy (45378). They are prepped, have an IV started, and are wheeled into the endoscopy suite. While the nurse is preparing the propofol but before it is administered, the patient experiences sudden, severe chest pain and shortness of breath. The gastroenterologist halts the procedure, stabilizes the patient, and transfers them to the emergency department.
| Field | Code | Rationale |
|---|---|---|
| CPT (Facility) | 45378--73 | ASC claim for the colonoscopy. Modifier -73 indicates it was stopped in the room prior to anesthesia administration[1,2]. |
| CPT (Physician) | 45378--53 | Physician’s professional claim. The physician uses -53 for discontinued procedures[2]. |
| PDx | Z12.11 | Encounter for screening for malignant neoplasm of colon (the original reason for the visit). |
| SDx | R07.9 | Chest pain, unspecified (the reason for the cancellation). |
| SDx | Z53.09 | Procedure not carried out due to contraindication. |
Note
The ASC will receive 50% of the standard facility fee for the colonoscopy to cover the room and supply overhead utilized[cite: 1].
Example 2 — HOPD: Discontinued Excision Before Local Anesthesia
Clinical Scenario: A patient is in the hospital outpatient minor surgery room for the excision of a 3.0 cm benign lesion on their back (11403). The patient is positioned prone on the table, and the surgical tray is opened. Right before the surgeon injects the local anesthetic (lidocaine), the patient has a severe panic attack, refuses the procedure, and cannot be calmed down. The surgeon cancels the excision.
| Field | Code | Rationale |
|---|---|---|
| CPT (Facility) | 11403--73 | HOPD facility claim. The procedure was stopped in the room before local anesthesia was injected[2]. |
| CPT (Physician) | 11403--53 | Surgeon’s claim for the discontinued professional service[2]. |
Warning
If the surgeon had already injected the lidocaine and then the patient had a panic attack, the facility would use modifier -74 instead, because local anesthesia had already been administered.
⚠️ Common Coding Pitfalls
- Confusing Modifier -73 with -74: Modifier -73 is strictly for cancellations before anesthesia. If any anesthesia (local, regional, or general) is given, or if the procedure physically begins (e.g., incision made, scope inserted), the facility must use modifier -74[1, 3].
- Physicians Using Modifier -73: Professional coders cannot use modifier -73. It is a facility-only modifier. Physicians use modifier -53[2].
- Cancellations in the Holding Area: If a patient’s vitals are unstable in the pre-op holding area and they are sent home without ever entering the procedure room, the facility cannot bill the surgical code with modifier -73. Modifier -73 requires the patient to have been taken to the procedure room[1].
📎 Sources
[1] Edition, T. (n.d.). The Guide to Medicare Preventive Services for Physicians, Providers, Suppliers, and Other Health Care Professionals Third Editio. https://lab.parkview.com/TestDirectoryFiles/MCARE%20PREVENTATIVE%20SVCS.pdf [2] Song, L., Saghafian, S., Newhouse, J. P., Landrum, M. B., & Hsu, J. (2020). The Impact of Vertical Integration on Physician Behavior and Healthcare Delivery: Evidence from Gastroenterology Practices. SSRN Electronic Journal. https://doi.org/10.2139/ssrn.3704941 [3] Test, F. (n.d.). Colorectal Cancer Screening. https://www.codemap.com/file/colorectalcancerscreening.pdf