Certified Professional Coder (CPC) Quiz: Apply Modifier Selection Rules
20 questions · exam conditions
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Apply Modifier Selection RulesQuestion 1 of 20

A second physician assumes postoperative management of a patient from the original surgeon partway through the global period. Which modifier does the second physician report?

-54
-55
-56
-24
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Certified Professional Coder (CPC) Quiz

Certified Professional Coder (CPC) Quiz: Apply Modifier Selection Rules

Practice Apply Modifier Selection Rules in Certified Professional Coder (CPC) with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Apply Modifier Selection Rules, giving you a quick way to practice the rules, question types, and explanations that matter most for Certified Professional Coder (CPC).

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

A second physician assumes postoperative management of a patient from the original surgeon partway through the global period. Which modifier does the second physician report?

  1. -54
  2. -55 (correct answer)
  3. -56
  4. -24
Explanation: Modifier -55 (Postoperative Management Only) is reported by a physician who assumes postoperative care from the original surgeon. The original surgeon would have reported modifier -54 (Surgical Care Only) to indicate they will not be providing postoperative management. The global fee is split proportionally between the two physicians based on the relative value of each care component.

Question 2

A physician who performed surgery on a patient sees the patient during the postoperative period for a new, unrelated medical problem. Which modifier is appended to the E/M code?

  1. -25
  2. -57
  3. -24 (correct answer)
  4. -79
Explanation: Modifier -24 (Unrelated Evaluation and Management Service by the Same Physician During a Postoperative Period) is used when the E/M visit addresses a condition unrelated to the original surgery during the global period. Without this modifier, the E/M would be considered bundled into the global surgical package. Modifier -24 establishes the separate and unrelated nature of the visit.

Question 3

A procedure performed via telehealth is delivered through a real-time interactive audio and video communications system. Which modifier identifies a synchronous telemedicine service?

  1. -GT
  2. -GQ
  3. -95 (correct answer)
  4. -93
Explanation: Modifier -95 identifies a synchronous telemedicine service rendered via real-time interactive audio and video communications. It is the current CPT® standard for real-time telehealth. Modifier -GT was a legacy Medicare telehealth modifier; -GQ is for asynchronous store-and-forward telecommunications; -93 is for audio-only telephone evaluation and management services. When coding for current CPT® compliance, -95 is preferred for synchronous telehealth.

Question 4

A surgeon performs an unrelated procedure during a patient's active global period from a prior surgery. Which modifier is appended to the unrelated procedure code?

  1. -24
  2. -58
  3. -78
  4. -79 (correct answer)
Explanation: Modifier -79 (Unrelated Procedure or Service by the Same Physician During the Postoperative Period) is used when a procedure unrelated to the original surgery is performed during the global period. Modifier -79 allows the unrelated procedure to be separately billed. A new global period begins for the unrelated procedure. This contrasts with modifier -78 (related complication requiring OR return) and -58 (planned staged procedure).

Question 5

A radiologist in an independent practice interprets a CT scan of the chest but does not own the equipment or perform the technical component. Which modifier identifies the professional component only?

  1. -26 (correct answer)
  2. -TC
  3. -52
  4. -32
Explanation: Modifier -26 (Professional Component) is appended when a physician provides only the interpretation and written report of a diagnostic service and does not perform the technical component. The technical component (equipment and technician) is reported with modifier -TC. The global service (both components by same provider/entity) is reported without a modifier.

Question 6

The same physician performs two separate procedures during the same operative session — a hernia repair and a cholecystectomy. Which modifier is appended to the lower-valued procedure to indicate multiple procedures?

  1. -59
  2. -22
  3. -25
  4. -51 (correct answer)
Explanation: Modifier -51 (Multiple Procedures) is appended to the secondary (lower-valued) procedure when multiple procedures are performed by the same provider during the same operative session. It signals to the payer that a fee reduction is appropriate. Modifier -51 is not used on add-on codes or modifier 51-exempt codes.

Question 7

A physician is asked by a third party (e.g., insurance company) to perform a mandated service such as a second surgical opinion. Which modifier indicates a mandated service?

  1. -32 (correct answer)
  2. -99
  3. -Q0
  4. -GT
Explanation: Modifier -32 (Mandated Services) is appended to a service that is required by a third party — such as an insurer, government agency, or peer review organization — including second surgical opinions, confirmatory consultations, and utilization reviews. It indicates the service was not initiated by the patient or physician but was required by an external party.

Question 8

A surgeon performs a procedure and plans to complete a second stage of the same procedure in 3 weeks. The second stage was planned at the time of the first procedure and will be performed during the global period. Which modifier is appended to the second-stage procedure?

  1. -76
  2. -77
  3. -78
  4. -58 (correct answer)
Explanation: Modifier -58 (Staged or Related Procedure or Service by the Same Physician During the Postoperative Period) is used for a planned or anticipated second-stage procedure performed during the global period of the original procedure. It also initiates a new global period. This differs from modifier -78 (return to OR for unplanned complication) or -79 (unrelated procedure).

Question 9

Two codes from different NCCI code pairs are being reported together. The procedures were genuinely performed at separate anatomical sites during the same encounter. Which modifier establishes their distinct nature to override the NCCI edit?

  1. -51
  2. -22
  3. -59 (correct answer)
  4. -25
Explanation: Modifier -59 (Distinct Procedural Service) is used to indicate that a procedure or service was distinct from another service performed on the same day — for example, a different session, site, organ, incision, or injury. It is used to override applicable NCCI bundling edits when the procedures were genuinely separate. The X modifiers (XE, XS, XP, XU) are more specific subsets of -59 when applicable.

Question 10

A surgeon performs a skin lesion excision under local anesthesia and also performs a more extensive wound repair that was not anticipated prior to the procedure. The additional repair required significantly more work than typical. Which modifier is appended to the procedure code?

  1. -22 (correct answer)
  2. -25
  3. -51
  4. -59
Explanation: Modifier -22 (Increased Procedural Services) is appended when the work required to perform a procedure is substantially greater than typically required. Documentation in the operative report must support the increased complexity. A special report is submitted with the claim. Modifier -22 applies to the procedure code itself, not to an E/M service.

Question 11

A physician provides a separate, significant E/M service on the same day as a minor procedure for an unrelated condition. Which modifier is appended to the E/M code?

  1. -24
  2. -57
  3. -79
  4. -25 (correct answer)
Explanation: Modifier -25 (Significant, Separately Identifiable Evaluation and Management Service by the Same Physician on the Same Day of a Procedure or Other Service) is used when an E/M beyond the pre-procedure assessment is performed on the same day as a procedure. It establishes that the E/M was a distinct, separately identifiable service. The E/M must address a condition separate from the procedure or be independently significant.

Question 12

A code requires more than one modifier to fully describe the service. For example, a bilateral procedure performed as a reduced service. Which modifier indicates that multiple modifiers are being applied?

  1. -51
  2. -99 (correct answer)
  3. -22
  4. -52
Explanation: Modifier -99 (Multiple Modifiers) is appended to a procedure code when two or more modifiers are necessary to fully describe the service. It alerts the payer that additional modifiers are present and associated with the code. The individual modifiers are then listed in addition. Some claim forms and electronic systems handle this automatically, but -99 remains the formal indicator when space or system constraints require it.

Question 13

A procedure is terminated after the patient is prepped and anesthesia has been administered, but before the surgical incision, due to a sudden drop in blood pressure. Which modifier is reported on the physician's claim?

  1. -52
  2. -53 (correct answer)
  3. -73
  4. -74
Explanation: Modifier -53 (Discontinued Procedure) is used by the performing physician when a procedure is terminated after the patient is prepared and anesthesia has been given, due to extenuating circumstances. Modifier -52 is for reduced services where the procedure is partially completed. Modifiers -73 and -74 are facility-specific (hospital outpatient) modifiers for discontinued procedures.

Question 14

A surgeon operates with an assistant surgeon who actively assists throughout the entire procedure. The assistant surgeon's role is limited to assisting — they do not perform a distinct portion independently. Which modifier does the assistant surgeon report?

  1. -62
  2. -80 (correct answer)
  3. -81
  4. -82
Explanation: Modifier -80 (Assistant Surgeon) is used by a physician who assists the primary surgeon throughout the entire procedure. Modifier -81 is for minimum assistant surgery (brief assistance); -82 is used when a qualified resident is unavailable and a non-resident physician assists. Modifier -62 is for two co-surgeons each performing distinct portions — not for one performing as an assistant to the other.

Question 15

Two distinct procedures are performed at separate anatomical sites, and the coder needs to differentiate them from a bundled pair. The distinguishing factor is that they were performed through separate incisions. Which X modifier most specifically indicates a separate incision/excision?

  1. XE
  2. XP
  3. XS (correct answer)
  4. XU
Explanation: The X modifiers are more specific subsets of modifier -59: XE (separate encounter), XP (separate practitioner), XS (separate structure), XU (unusual non-overlapping service). When two procedures are performed through separate incisions on separate structures or anatomical sites, XS (Separate Structure) most precisely reflects this distinction. XS is preferred over -59 when the specific reason is a different anatomical structure or organ.

Question 16

A procedure is completed but at a reduced level — for example, only one of the planned two sinuses was drained due to patient tolerance. Which modifier indicates the service was reduced from its standard description?

  1. -22
  2. -53
  3. -58
  4. -52 (correct answer)
Explanation: Modifier -52 (Reduced Services) is appended when a service or procedure is partially reduced or eliminated at the physician's discretion. The procedure was initiated and completed — but in a lesser manner than fully described by the code. Modifier -53 is for procedures discontinued before completion; -52 is for procedures completed but at a reduced scope.

Question 17

A physician performs the same procedure on a patient during a subsequent encounter in the same day due to a recurrent problem. The same provider repeats the procedure. Which modifier is appended?

  1. -76 (correct answer)
  2. -77
  3. -78
  4. -79
Explanation: Modifier -76 (Repeat Procedure or Service by Same Physician or Other Qualified Health Care Professional) is used when the same provider repeats a procedure on the same day. This distinguishes the repeated service from the initial procedure and notifies the payer it was not a duplicate claim. Modifier -77 is for the same procedure repeated by a different physician.

Question 18

A laboratory test is repeated on the same day for the same patient because the first result was borderline and required confirmation. The same physician orders the repeat test. Which modifier is appended to the repeated lab code?

  1. -76
  2. -77
  3. -91 (correct answer)
  4. -90
Explanation: Modifier -91 (Repeat Clinical Diagnostic Laboratory Test) is used when the same test is repeated on the same day on the same patient to obtain subsequent test results. It is not used for test reorders due to specimen problems. Modifier -76 is for repeat procedures (non-lab), not specifically for repeat lab tests. Modifier -91 specifically addresses the clinical need to perform the same lab test multiple times in one day.

Question 19

A pathologist performs laboratory tests in their office and sends a specimen to an outside reference laboratory for a specialized test. Which modifier is appended to the reference lab test when billed by the ordering physician?

  1. -91
  2. -32
  3. -90 (correct answer)
  4. -59
Explanation: Modifier -90 (Reference [Outside] Laboratory) is appended when laboratory procedures are performed by a party other than the treating or reporting physician, and the physician bills for the test. This modifier notifies the payer that the test was sent to a reference laboratory rather than performed in the physician's own lab.

Question 20

A non-physician (physician assistant) assists at surgery under the direction of the supervising physician. Which HCPCS modifier identifies a non-physician assistant at surgery?

  1. -80
  2. -81
  3. -82
  4. -AS (correct answer)
Explanation: HCPCS modifier -AS (Assistant at Surgery) identifies when a non-physician provider — such as a physician assistant (PA), nurse practitioner (NP), or clinical nurse specialist (CNS) — serves as an assistant at surgery. This is distinct from CPT® modifier -80 (which applies to physician assistant surgeons), and is used for Medicare billing when a qualified non-physician acts in the assistant role.