Modifier 52 vs 53: CPT® Codes For Aborted, Unsuccessful, Incomplete or Discontinued Procedure.

This CPT® code lecture describes how to use modifier 52 vs 53 for procedures that have been reduced or discontinued during aborted, unsuccessful or incomplete surgeries or procedures.  If you are like me, I have had a hard time understanding how to choose modifier 52 or 53 based on different situations I may find myself in. I believe the confusion is a direct result of the choice of words used to define these two modifier codes.  I don't believe they clearly  describe real life clinical situations where surgeries or other procedures may be discontinued or reduced for any number of reasons.  I am an internal medicine trained hospitalist physician with over a decade of experience providing hospitalist care.  I occasionally perform invasive interventions, mostly by way of central venous catheter placement.    Not all central lines are successful to their completion.   What modifier should I pick if my central line procedure was aborted before completion?  This lecture should help the clinician understand how to bill for procedures that are reduced or discontinued. 


How does the book of Current Procedural Terminology (CPT®) define modifiers -52 and -53?  I recommend the AMA's CPT® 2018 Standard Edition as the definitive resource for CPT® coding.    
Modifier 52  Reduced Services: Under certain circumstances, a service or procedure is partially reduced or eliminated at the physician’s discretion. Under these circumstances, the service provided can be identified by its usual procedure number and the addition of the modifier 52, signifying that the service is reduced. This provides a means of reporting reduced services without disturbing the identification of the basic service.

Modifier 53 Discontinued Procedure: Under certain circumstances, the physician may elect to terminate a surgical or diagnostic procedure. Due to extenuating circumstances, or those that threaten the well-being of the patient, it may be necessary to indicate that a surgical or diagnostic procedure was started but discontinued.
As I indicated above, these definitions are unfortunate because the terminology is vague and open to interpretation.  I'm not sure what defines extenuating circumstances. In fact, I'm not even sure CMS has a formal definition of extenuating circumstances.  I even found one CMS resource asking for public comment on how to define extenuating circumstances (on page 55) for another policy issue.  In addition,  some procedures that may be discontinued for reasons other than the well-being of the patient.  How should one bill for a central line that cannot be completed to its entirety because the vein could not be cannulated due to morbid obesity?  If the procedure was aborted for complexity of the patient anatomy, is this an extenuating circumstance?  If the physician documents that  they discontinued the procedure because further attempts could threaten the well-being of the patient, should this be enough to get paid using modifier 53 for an incomplete procedure?

I think the reason so much confusion exists between using modifier 52 vs 53 lies in the choice of words used to define the codes and their descriptions as well.  Discontinued procedures are reduced services and reduced services could be the result of discontinuing a procedure at anytime during the ongoing intervention.  After a thorough review of multiple resources, I have made my own conclusions about how to interpret the difference between these two modifier codes.
  • I believe if the intended procedure or surgery is completed, but the description of the intended and completed intervention is less than any defined CPT® code, modifier -52 should be used. 
  • But, if a procedure or surgery was unsuccessful, incomplete, discontinued or aborted I would submit for payment of the intended CPT® code and add modifier -53 with an explanation of the extenuating circumstances or documentation detailing how continuing the procedure could threaten the well-being of the patient.  Is it possible to abort a procedure for other reasons?  I suppose it is.  But, I suspect, short of a physicians cancelling a procedure midway to completion because the ball game was about to start, most of the time, the procedure is discontinued because continuation does involved extenuating circumstances (whatever that is defined as) or potential harm to the patient.  This is where clear documentation should prevail. 
Since this is just my interpretation, I really wish the AMA and CMS would provide much greater clarity (using a different choice of words) and provide greater concrete examples for these two modifier codes.  Heck, if there was no question about which code to chose, you probably wouldn't be reading this now!



As with most coding compliance issues, good documentation is required to justify use of this modifier code.   I have reviewed multiple resources and have found numerous examples of appropriate and inappropriate uses of modifier -52.  I have tried my best to detail them here.  Several resources provided conflicting indications for or against the use of  modifier 52, especially when procedures have been  started but had to be aborted for reasons other than being clearly defined as threatening the patient's well-being..



  • Use when a CPT® or HCPCS code exists to describe most of the procedure but no code exists for the intended reduced service provided.
  • Use when an intended procedure is completed, but the procedure is less than is described in the CPT® or HCPCS code.
  • Use when a surgeon performs a bilateral CPT® described procedure on one side only.
  • Use when a surgeon calls in another surgeon to manage another finding discovered during an operation.  The second surgeon would code their surgery using modifier -52 to indicate they did not open and close the patient.  
  • Use when a procedure which is normally performed on a bilateral approach involves only unilateral completion due to difficulties in completing the intervention.
  • Some resources suggested modifier 52 could be used to describe an aborted procedure or an attempted procedure that could not be completed for reasons other than extenuating circumstances or that threaten the well-being of the patient.  Other resources disagreed.  My own belief is that, at least for hospitalist medicine, most of the time, modifier 53 should be used for discontinue procedures instead. 
  • One resource (link no longer available) gave this example:  
    • A cardiologist attempts to perform a balloon angioplasty or stent placement in the coronary artery but is unable to complete the procedure because of an anatomic variation.     
    • I'm not convinced this is the appropriate use of modifier 52.  As a discontinued procedure, I suspect, continued attempts to finish the procedure could be considered endangering the well-being of the patient and this could be considered a candidate for modifier -53 instead.  This resource linked above argues that incomplete or aborted procedures that are discontinued for reasons other than for the well being of the patient should use modifier 52.  I cannot say with great certainty that  I agree with this.  Other resources suggest modifier 52 should not be used for terminated or incomplete procedures.  I think in most clinical situations, the discontinuation of a procedure due to an anatomic or clinical reason could easily fall under the documentation  requirements of modifier -53, not 52, which I believe is intended for procedures that are completed to their entirety, just with a description less than a defined CPT® code. 



  • If a CPT® code accurately describes a procedure as unilateral or bilateral, don't use modifier -52 if a bilateral procedure was converted to a unilateral procedure or if a multiview x-ray was converted to a single view x-ray when a CPT® code exists for the reduced service.
  • Don't use modifier -52 if one procedure approach is unsuccessful followed by an alternative approach that is successful during the same intervention time frame.
  • Don't use modifier -52 with evaluation and management (E/M) encounters.  Although some payers may allow this, Medicare does not.  They say so:
    • CPT modifier -52 (reduced services) must not be used with an evaluation and management service. Medicare does not recognize modifier -52 for this purpose (on page 40/231)
  • Don't use modifier -52 for procedures that were terminated (intended but not completed).  This contradicts other resources detailed above.
  • Don't use modifier -52 for time based codes.
  • Don't use for an incomplete procedure.
  • Don't use to provide payment discounts to patients.
  • Do not use modifier -52 to indicate elective cancellation of an intervention before anesthesia induction and or surgical preparation in the operating suite.




  • For reduced surgical services using modifier 52, make sure to provide your payer with the operative report and a concise statement detailing how the service provided is different than the CPT® code.  Failure to provide a concise statement will result in denial of the claim.  The statement may be provided in the operative report but must be clearly identified.  Special considerations for ophthalmology, Ambulatory Surgical Centers (ASCs) and radiology claims are reviewed here.  
  • For nonsurgical reduced procedures, indicate the service that was not provided.  Chapter 12 of the Medicare Claims Processing Manual details documentation and reimbursement (linked just below).   
  • Section 40-2 -Billing Requirements for Global Surgery under section 10 Unusual Circumstances states the following  on page 101/231:
Surgeries for which services performed are significantly greater than usually required may be billed with the “-22” modifier added to the CPT code for the procedure. Surgeries for which services performed are significantly less than usually required may be billed with the “-52” modifier. The biller must provide: • A concise statement about how the service differs from the usual; and • An operative report with the claim. Modifier “-22” should only be reported with procedure codes that have a global period of 0, 10, or 90 days. There is no such restriction on the use of modifier “-52.”



  • Different payers may treat modifier 52 differently.  They may apply a standardized percentage reduction in service or they may base their payment on the documentation you provide for them. For example, this resource says UnitedHealthcare pays 50% (link no longer available).   Some payers may not recognize this modifier at all.  Consider billing your full price and let the payer reduce the price or negotiate your price based on your documentation. 
  • How does Medicare handle Modifier 52?  From the Medicare Claims Processing Manual (page 21/231):
    • 20.4.6 - Payment Due to Unusual Circumstances (Modifiers “ - 22” and “ - 52”) (Rev. 1, 10 - 01 - 03) B3 - 15028:  The fees for services represent the average work effort and practice expenses required to provide a service. For any given procedure code, there could typically be a range of work effort or practice expense required to provide the service. Thus, carriers may increase or decrease the payment for a service only under very unusual circumstances based upon review of medical records and other documentation.
    •  Section 40.4-Adjudication of Claims For Global Surgery in the Medicare Claims Processing Manual states on page 105/231:  
      • Claims for surgeries billed with a “-22” or “-52” modifier, are priced by individual consideration if the statement and documentation required by §40.2.A.10 are included. If the statement and documentation are not submitted with the claim, pricing for “-22” is it the fee schedule rate for the same surgery submitted without the “-22” modifier. Pricing for “-52” is not done without the required documentation.



For hospitalists, I believe most of the time we should be  using modifier 53 on our procedures (central line, thoracentesis, paracentesis, lumbar puncture) that are discontinued before completion. Most of the time a procedure is aborted, it will be because of anatomical reasons, medical stability reasons or agitation that prevents a safe completion.  I've read some resources that suggest failure to complete the test because of anatomical reasons should be coded with modifier 52.  My position, at least for what most types of procedures hospitalists do, is that we are going to discontinue our procedures if we are unsuccessful to completion and further attempts risk harm to the patient.




  • Use for procedures that are terminated prior to completion.  I provide a special review of colonoscopy due to additional guidance by CMS:
    • Use if a colonoscopy is discontinued due to a poor colon preparation or anatomic variation that prevents completion.  This is specifically described in detail in the Medicare Claims Processing Manual Chapter 12 Section 30.1.B (page 27/231)
      • Incomplete Colonoscopies (Codes 45330 and 45378) An incomplete colonoscopy, e.g., the inability to extend beyond the splenic flexure, is billed and paid using colonoscopy code 45378 with modifier “ - 53. ” The Medicare physician fee schedule database has specific values for code 45378 - 53. These values are the same as for code 45330, sigmoidoscopy, as failure to extend beyond the splenic flexure means that a sigmoidoscopy rather than a colonoscopy has been performed. However, code 45378 - 53 should be used when an incomplete colonoscopy has been done because other MPFSDB indicators are different for codes 45378 and 45330. 
      • Interrupted covered screening colonoscopies:  Review pages 126 and 127 here from the Medicare Claims Processing Manual Chapter 18. 
    • A surgery is aborted because the patient's vitals signs decompensate.
  • Use if the surgery or procedure is discontinued after anesthesia is administered.
  • Use when the procedure is discontinued due to "extenuating circumstances".  Unfortunately, I have not been able to find how this phrase is defined in clinical situations.I believe this is why this code can be used for most clinical situations where a physician has elected to discontinue a procedure or surgery, especially in hospitalist medicine.
  • Use for discontinued procedure after induction of anesthesia.
  • Use if equipment malfunction prevents completion of the intended procedure. 
  • Use if the procedure is terminated for reasons beyond the physician's control.  This would appear to qualify as an extenuating circumstance.
  • Use when the patient is having a complication of the procedure
  • Use when the patient cannot tolerate the procedure.



  • Don't use modifier 53 with E/M services.
  • Don't use modifier 53 with time based codes.
  • Don't use when converting a laparoscopic or endoscopic intervention  to an open intervention. 
  • Do not use for elective cancellation of a surgery or procedure.  
  • Don't use for discontinued surgeries prior to anesthesia induction or surgical prep.
  • Not for use by ASCs.  They are instructed to use modifiers -73 and -74.  See below. 



  • Provide operative report documenting why and at what point in the procedure it was medically necessary to discontinue. If the procedure was not surgical, provide a statement or report detailing how the procedure that was done differed from usual.
  • Provide the length and amount of procedure completed and the reason for discontinuing the procedure. 




  • Reduce the normal fee by the percentage of the service you did not provide.
  • Ultimately, you're gonna get paid whatever the insurance company  says they're going to pay you and you'll have to go through whatever appeals process they have in place for denials or reductions in claims if you want payment for your services.
Other considerations for using modifier 52 and 53
  • From Medicare Claims Processing Manual Chapter 13 page 52/73 on Section 80.1 regarding physician presence for Supervision and Interpretation (S&I codes) and Interventional Radiology:
    • Radiologic supervision and interpret ation (S&I) codes are used to describe the personal supervision of the performance of the radiologic portion of a procedure by one or more physicians and the interpretation of the findings. In order to bill for the supervision aspect of the procedure, the physician must be present during its performance. This kind of personal supervision of the performance of the procedure is a service to an individual beneficiary and differs from the type of general supervision of the radiologic procedures performed in a hospital for which FIs pay the costs as physician services to the hospital. The interpretation of the procedure may be performed later by another physician. In situations in which a cardiologist, for example, bills for the supervision (the “S”) of the S &I code, and a radiologist bills for the interpretation (the “I”) of the code, both physicians should use a “ - 52” modifier indicating a reduced service, e.g., only one of supervision and/or interpretation. Payment for the fragmented S&I code is no more th an if a single physician furnished both aspects of the procedure. 



    The Centers For Medicare & Medicaid Services provided provided guidance for hospitals' use of modifiers 52, 52, 73 and 74 for discontinued services.  With the addition of modifiers 73 and 74, modifiers 52 and 53 were revised.

    20.6.4 - Use of Modifiers for Discontinued Services (Rev 2386, Issued: 01 - 13 - 12, Effective: 01 - 01 - 12, Implementation: 01 - 03 - 12 ) In Transmittal 2386 for Change Request 7672 dated January 13th, 2012.  See pages 36 and 37 for complete details.  Below is an excerpt

    Modifiers provide a way for hospitals to report and be paid for expenses incurred in preparing a patient for a procedure and scheduling a room for performing the procedure where the service is subsequently discontinued. This instruction is applicable to both outpatient hospital departments and to ambulatory surgical centers.
    - 52 is used to indicate partial reduction, cancellation, or discontinuation of services for which anesthesia is not planned. The modifier provides a means for reporting reduced services without disturbing the identification of the basic service 
    - 53 is used to indicate discontinuation of physician services and is not approved for use for outpatient hospital services
    What effect does discontinuation of procedures have on ASC payments?  Modifiers 73 and 74 are ASC codes.  These should not be used by physicians.
    Procedures that are discontinued after the patient has been prepared for the procedure and taken to the procedure room but before anesthesia is provided will be paid at 50 percent of the full OPPS payment amount. Modifier - 73 is used for these procedures. 
    Procedures that are discontinued , partially reduced or cancelled after the procedure has been initiated and/or the patient has received anesthesia will be paid at the full OPPS payment amount. Modifier - 74 is used for these procedures. 
    Procedures for which anesthesia is not planned that are discontinued , partially reduced or cancelled after the patient is prepared and taken to the room where the procedure is to be performed will be paid at 50 percent of the full OPPS payment amount. Modifier - 52 is used for these procedures.
    Anesthesia is defined to include local, regional block(s), modera te sedation/analgesia (“conscious sedation”), deep sedation/analgesia, and general anesthesia.
    Further description of modifiers 73 and 74 for hospital outpatient payment (OPPS) adjustments is described here as well on pages 8 and 9 (Transmittal 442 Change Request 3507).
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