Modifiers · CPT modifier

Reduced services

Modifier 52 signals to a payer that a procedure or service was intentionally scaled back or partially omitted at the treating provider's discretion—not abandoned due to a complication. The same CPT code for the full procedure is retained; the modifier communicates that less work was performed than that code's standard descriptor defines, allowing accurate reimbursement without creating a new code identity.

Verified May 8, 2026 · 9 sources ↓

Type: CPT
CPT codes use it: 975
Top regions: Other, Foot & ankle, Wrist

Drawn from CMSNovitasCgsmedicareFCSOHopkinsmedicine

When to use modifier 52

Source · Editorial brief grounded in 9 cited references ↓

Append modifier 52 to a CPT code when the physician deliberately performed a reduced version of a procedure and no anesthesia was administered (or planned). Classic orthopedic scenarios include performing a unilateral procedure on a code whose descriptor specifies bilateral work, completing only a portion of a multi-component revision arthroplasty, or obtaining fewer radiographic views than the CPT code's standard requirement. The reduction must be intentional and clinically documented—not the result of a patient emergency or intraoperative complication.

Modifier 52 also applies in radiology when supervision and interpretation are split between two providers and no CPT code precisely matches the reduced service. In those cases, place the component modifier (TC or 26) first, then append 52 in the second position. For ambulatory surgical center (ASC) facility claims involving a non-anesthesia procedure that is discontinued, modifier 52 is the correct facility-side indicator; ASC claims billed with modifier 52 are not subject to the standard multiple-procedure reduction.

Do not use modifier 52 for procedures stopped after anesthesia induction—modifier 53 (physician) or modifiers 73/74 (facility) govern those situations. Do not append it to evaluation and management codes or to time-based codes where the duration of service is itself the billing variable; for timed codes, document actual minutes rendered instead.

Orthopedic scenarios

Concrete situations in orthopedic practice that warrant modifier 52.

Source · Editorial brief grounded in AAOS coding guidance and cited references ↓

Revision total hip arthroplasty (CPT 27134) planned for both acetabular and femoral components: the surgeon replaces only the acetabular component and femoral liner but not the femoral stem. Bill 27134-52 with an operative note explaining which components were addressed and why full revision was not performed.
Bilateral lower-extremity non-invasive vascular study (CPT 93923) ordered for both legs but the patient cannot tolerate positioning on the right side: the study is completed on the left leg only. Bill 93923-52 with a claim narrative noting 'left leg only—patient intolerance precluded right-sided study.'
Knee arthroscopy with partial medial meniscectomy (CPT 29881) initiated but the surgeon determines that only a limited synovial debridement—less than the full meniscal work described—is clinically appropriate and safe given cartilage findings: bill 29881-52 with documentation specifying the reduced scope of meniscal work performed.
ORIF of a distal radius fracture (CPT 25600 or 25607) planned with multiple fixation points: intraoperative imaging confirms that fewer screws and a shorter plate construct achieve adequate fixation, materially reducing operative work. Bill the applicable ORIF code with modifier 52 and document the abbreviated construct in the operative report.
Radiographic series of the lumbar spine (CPT 72100) ordered for four views; the patient experiences pain and only two views are obtained before the study is stopped by the radiologist as clinically sufficient: bill 72100-52 and note 'two views obtained' in the claim narrative.
Planned bilateral knee arthroplasty (CPT 27447 billed with modifier 50) where the surgeon completes only the left TKA during the session due to prolonged operative time and patient hemodynamic considerations that do not rise to the level of an emergency: bill 27447-52 for the single completed knee with documentation of the clinical rationale for deferring the contralateral side.

Common mistakes

Where coders most often go wrong with modifier 52.

Source · Editorial brief grounded in CMS NCCI Policy Manual and cited references ↓

Appending modifier 52 to E/M codes (e.g., 99213, 99214): payers universally reject this pairing because E/M work is time- or complexity-based, not procedure-component-based.
Confusing modifier 52 with modifier 53: use 52 when the surgeon completed a reduced version of the procedure by design; use 53 only when the procedure was stopped mid-course due to patient instability or safety concerns.
Submitting modifier 52 after anesthesia was induced: once anesthesia is active and the operative procedure has begun, modifier 53 (physician) or 74 (ASC facility) applies—not 52.
Omitting supporting documentation or claim narrative: CMS contractors expect the claim to state when the procedure started, why it was reduced, and approximately what percentage of the procedure was completed; missing this triggers automatic denial.
Using modifier 52 on time-based CPT codes instead of simply billing the unit count that reflects actual time: appending 52 to a 15-minute timed code is inappropriate when the correct action is to bill fewer units.
Placing modifier 52 in the first position when a fee-reducing modifier (TC or 26) is also present: modifier 52 must occupy the second modifier slot in that scenario.
Billing modifier 52 when an exact CPT code already exists for the reduced service: if CPT has a unilateral code and a bilateral code, bill the unilateral code directly rather than attaching 52 to the bilateral code.

CPT codes that use modifier 52

975 orthopedic CPT codes in our reference list this modifier as applicable. Sorted by total RVU.

Source · Derived from per-code modifier guidance in our CPT reference

Showing top 12 of 975 by total RVU.

Where modifier 52 shows up

Body regions where this modifier most commonly appears in our orthopedic reference.

Other 172 codes
Foot & ankle 136 codes
Wrist 113 codes
Hand 106 codes

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 9 cited references ↓

01How much does modifier 52 reduce payment?

For radiology and non-anesthesia procedures, CMS contractors typically apply a 50% reduction to the fee schedule amount. For surgical services, payment is based on documentation of what was actually performed—CGS Medicare, for example, reviews the operative report to determine an individualized reduction rather than applying a flat 50%. Always verify the specific payer's policy because some commercial plans (e.g., Healthy Blue Louisiana) contractually set modifier 52 reimbursement at 50% of the applicable fee schedule for all service types.

02What is the difference between modifier 52 and modifier 53?

Modifier 52 applies when the physician intentionally performed a scaled-back version of the procedure and completed what they set out to do at that reduced scope—no anesthesia is involved. Modifier 53 applies when a procedure was started but had to be terminated before completion due to patient safety concerns or unexpected clinical events, and it is used on physician claims only. If the procedure was stopped after anesthesia induction at an ASC, use modifiers 73 or 74 on the facility claim instead.

03Can modifier 52 be used on evaluation and management (E/M) codes?

No. Modifier 52 is explicitly prohibited on E/M codes. E/M services are selected based on medical decision-making complexity or total time, so the code itself already reflects the level of work. Appending modifier 52 to an E/M code will result in claim denial by most payers and is flagged as a coding error by CMS and commercial contractors alike.

04Does modifier 52 apply to ASC facility claims?

Yes, but only for procedures not requiring anesthesia. ASCs use modifier 52 to indicate a non-anesthesia procedure was discontinued or reduced; importantly, ASC claims billed with modifier 52 are exempt from the standard multiple-procedure reduction. For procedures requiring anesthesia that are stopped, ASCs should use modifiers 73 (before anesthesia induction) or 74 (after anesthesia induction) on the facility claim.

05What documentation must accompany a modifier 52 claim?

The claim narrative or attached operative/procedural report should state when the procedure started, the reason the service was reduced, and the approximate extent (percentage or specific components) of the procedure that was completed. Novitas Solutions and other Medicare contractors have issued guidance that claims without this supporting information will be denied; the documentation is also the primary basis payers use to calculate the appropriate payment reduction for surgical services.

06Is modifier 52 appropriate when a bilateral procedure is done unilaterally?

Only if the CPT code does not already have a separate unilateral descriptor. If CPT provides both a unilateral code and a bilateral code for the same procedure, bill the unilateral code directly. If the code is inherently bilateral or the descriptor covers both sides without a distinct unilateral option, then billing the same code with modifier 52—along with a notation of which side was treated—is the correct approach.

07Where does modifier 52 go when modifier TC or 26 is also reported?

Modifier 52 must appear in the second modifier position. For example, if a radiologist performs only the interpretation component of a reduced radiology service, the claim line should read: CPT code – modifier 26 (first position) – modifier 52 (second position). Reversing the order or placing modifier 52 first can cause claim processing errors.

Sources & references

Editorial content was developed using the following public sources. Last verified May 8, 2026.

01
cms.gov
https://www.cms.gov/transmittals/downloads/R442CP.pdf
02
cms.gov
https://www.cms.gov/Regulations-and-Guidance/Guidance/Manuals/Downloads/clm104c12.pdf
03
novitas-solutions.com
https://www.novitas-solutions.com/webcenter/portal/MedicareJH/pagebyid?contentId=00144533
04
cgsmedicare.com
https://www.cgsmedicare.com/partb/pubs/news/2012/0712/cope19315.html
05
medicare.fcso.com
https://medicare.fcso.com/coding/modifier-52-fact-sheet
06
hopkinsmedicine.org
https://www.hopkinsmedicine.org/-/media/johns-hopkins-health-plans/documents/policies/rpc020-reduced-procedures.pdf
07
provider.healthybluela.com
https://provider.healthybluela.com/docs/gpp/LA_CAID_DistinctProceduralServices.pdf
08AMA CPT Professional Edition – Appendix A: Modifiers (current year)
09CMS NCCI Policy Manual for Medicare Services – Chapter 1, General Correct Coding Policies

Mira AI Scribe

When dictating a note that will support a modifier 52 claim, the operative or procedural report must answer three questions for the payer: (1) At what point in the procedure did the provider determine a reduction was appropriate? (2) What is the clinical reason the full procedure was not completed—and confirm it was a deliberate, elective decision rather than a patient emergency? (3) What percentage or which components of the procedure were actually performed? For orthopedic cases, explicitly name the components addressed (e.g., 'acetabular liner exchanged; femoral stem retained due to stable fixation on intraoperative imaging') and those omitted. For radiology, state the number of views or projections completed versus those ordered. Avoid vague language like 'procedure partially performed'—quantify the reduction. This documentation is the primary defense if a Medicare contractor or commercial payer requests medical records after receiving a modifier 52 claim.

See how Mira flags modifier 52 in dictation