22 Modifiers & HCPCS Level II Practice Questions & Answers

1. 1. A coder appends a modifier to a CPT code even though nothing in the documentation describes the circumstance that modifier reports. Why is an unsupported modifier treated as a compliance problem rather than a formatting mistake?

   • A.It only reorders the line items on a claim, so an unsupported modifier makes the payer reject the whole file.
   • B.It alters what the line asserts about the service, so an unsupported modifier is a false statement on a claim.✓ Answer
   • C.It is stripped by the clearinghouse before submission, so an unsupported modifier never reaches the payer at all.
   • D.It merely signals that records exist, so an unsupported modifier only triggers a routine request for the notes.

   A modifier is a substantive assertion about the service: it tells the payer that the circumstances of the service differed from the base code description. When the record does not support it, the claim line states something untrue, and knowingly submitting or causing such a claim is the conduct the False Claims Act reaches, no specific intent to defraud being required.

   Source: CPT Appendix A (purpose of modifiers); False Claims Act, 31 U.S.C. 3729(a)(1)(A)-(B)Report a problem with this question

2. 2. An established patient comes in for a scheduled therapeutic joint injection. At the same visit the physician also evaluates newly reported chest tightness, documents a separate history, examination and medical decision making, and orders an ECG. What modifier use is correct?

   • A.No modifier on the E/M code, since any evaluation on the day of a minor procedure is included in that procedure.
   • B.Modifier 59 on the E/M code, reporting a distinct procedural service furnished at a separate patient encounter.
   • C.Modifier 57 on the E/M code, reporting the visit at which the decision for that day's procedure was made.
   • D.Modifier 25 on the E/M code, reporting a significant, separately identifiable evaluation on the same day as the procedure.✓ Answer

   Modifier 25 exists precisely for an evaluation and management service that is significant and separately identifiable from the other service furnished the same day; the chest-tightness work-up is unrelated to the injection and stands on its own documentation. Modifier 59 is a procedural modifier and is never appended to an E/M code, and modifier 57 applies only to the decision for major surgery carrying a 90-day global period.

   Source: CPT Appendix A, modifiers 25, 57 and 59Report a problem with this question

3. 3. On one date a physician destroys a lesion on the arm and excises a different lesion on the back, and an NCCI edit pairs the two procedure codes. The same physician also documents a significant, separately identifiable E/M service. How should the modifiers be distributed?

   • A.Modifier 59 goes on the E/M code and on both procedure codes, since all three services were distinct.
   • B.Modifier 25 goes on the E/M code and modifier 59 goes on the second procedure code named by the edit.✓ Answer
   • C.Modifier 25 goes on both procedure codes and the E/M code is reported with no modifier appended to it.
   • D.Modifier 59 goes on the E/M code and modifier 25 goes on the second procedure code named by the edit.

   The two modifiers answer different questions: 25 tells the payer that an E/M service was significant and separately identifiable from a procedure done the same day, while 59 tells the payer that one procedure was distinct from another procedure that an edit would otherwise bundle. Because they attach to different kinds of codes, 25 belongs on the E/M line and 59 on the column-two procedure line.

   Source: CPT Appendix A, modifiers 25 and 59; NCCI Policy Manual, Chapter IReport a problem with this question

4. 4. For a Medicare patient, two procedures are performed on clearly different anatomic structures. The codes are paired by an NCCI procedure-to-procedure edit whose modifier indicator is 1. Which modifier does CMS instruct the coder to prefer?

   • A.Modifier XP on the column-two code, because the services were performed by a separate practitioner that day.
   • B.Modifier XU on the column-two code, because the service was unusual and did not overlap the main service.
   • C.Modifier XE on the column-two code, because the services were performed at a separate patient encounter.
   • D.Modifier XS on the column-two code, because the services were performed on a separate organ or structure.✓ Answer

   CMS created the X{EPSU} subset to replace the broad modifier 59 whenever one of the four specific reasons fits, and XS is defined as a service on a separate organ or structure. A modifier indicator of 1 means an appropriate modifier may bypass the edit, so the more specific XS is the correct choice rather than the generic 59.

   Source: CMS MLN, Proper Use of Modifiers 59, XE, XP, XS, XU; NCCI Policy Manual, Chapter IReport a problem with this question

5. 5. A diagnostic procedure is performed in the morning. Later the same day the identical procedure must be repeated, and this time a physician from a different group practice performs it. Which modifier belongs on the second claim line?

   • A.Modifier 91, identifying a repeat service performed to obtain successive results in the course of treatment.
   • B.Modifier 76, identifying a repeat procedure performed by the same physician who furnished the original one.
   • C.Modifier 59, identifying a distinct service that was separate from the procedure performed earlier that day.
   • D.Modifier 77, identifying a repeat procedure performed by a physician other than the one who furnished the first.✓ Answer

   The repeat pair turns entirely on who performed the second service: 76 is a repeat by the same physician or other qualified health care professional, and 77 is a repeat by another one. Modifier 91 belongs to repeat clinical diagnostic laboratory tests, not to procedures, so identity of the practitioner is the deciding fact here.

   Source: CPT Appendix A, modifiers 76 and 77Report a problem with this question

6. 6. Consider two situations. In the first, the physician plans a two-sided study but by choice, with no complication, performs only one side. In the second, after preparation and after the procedure has begun, it is terminated because the patient becomes unstable. Which pairing is correct?

   • A.Modifier 52 for the electively reduced service and modifier 53 for the procedure stopped after it began.✓ Answer
   • B.Modifier 53 for both situations, because in each case the physician did not complete the service described.
   • C.Modifier 53 for the electively reduced service and modifier 52 for the procedure stopped after it began.
   • D.Modifier 52 for both situations, because in each case less than the full described service was furnished.

   Modifier 52 reports a service partially reduced or eliminated at the physician's election, where the reduction was a deliberate choice and not a response to trouble. Modifier 53 reports a procedure that was actually started and then discontinued because of circumstances threatening the patient's wellbeing, which is what happened in the second situation.

   Source: CPT Appendix A, modifiers 52 and 53Report a problem with this question

7. 7. A radiologist practicing in an independent imaging office owns the equipment, employs the technologist who acquires the images, and personally interprets the study and writes the report. How is the radiologic code reported?

   • A.Report the code with modifier TC appended, because the practice supplied the equipment, supplies and technologist.
   • B.Report the code with modifier 26 appended, because the physician personally produced the written interpretation.
   • C.Report the code twice, once with modifier 26 and once with TC, to capture both halves of the global service.
   • D.Report the code with no component modifier, because one entity furnished both the equipment and the reading.✓ Answer

   Modifier 26 reports only the professional component, the physician work of interpretation and the written report, and TC reports only the technical component, the equipment, supplies and staff. When a single entity furnishes both, the service is global and neither modifier is used, since splitting it would report the same work twice.

   Source: CPT Appendix A, modifier 26; HCPCS Level II modifier TCReport a problem with this question

8. 8. A surgeon performs the same procedure on the right knee and on the left knee during one operative session. The code descriptor does not itself state that the procedure is bilateral. Which statement about modifier use is correct?

   • A.Modifier 59 reports it as bilateral, because the second knee is a distinct site from the knee done first.
   • B.Modifier 50 is barred here, because a code whose descriptor omits the word bilateral can never accept it.
   • C.Modifier 50 reports it as bilateral, because the identical service was done on both sides during one session.✓ Answer
   • D.Modifier 51 reports it as bilateral, because two separate services were furnished during the same session.

   Modifier 50 exists for exactly this situation: the same procedure performed on mirror-image sides of the body at the same session, on a code that is not already described as bilateral. Modifier 51 reports different procedures rather than sidedness, and modifier 59 is a last-resort distinct-service modifier, not a laterality statement.

   Source: CPT Appendix A, modifier 50Report a problem with this question

9. 9. CPT Appendix D lists the add-on codes. Why is modifier 51 never appended to a code that appears on that list?

   • A.An add-on code may be reported only once per operative session, so a multiple-procedure modifier would duplicate a line.
   • B.An add-on code already describes work extra to a primary procedure, so the multiple-procedure reduction does not apply.✓ Answer
   • C.An add-on code must instead carry modifier 22, which shows that the session demanded work beyond the usual service.
   • D.An add-on code must instead carry modifier 59, which shows that the extra work was distinct from the primary procedure.

   An add-on code is defined as additional work performed with a primary procedure and is valued that way from the start, so the payment reduction that modifier 51 signals would double-count a discount already built into the code. CPT therefore designates add-on codes as exempt from modifier 51.

   Source: CPT Appendix D (add-on codes); CPT Appendix A, modifier 51Report a problem with this question

10. 10. A malignant skin lesion is excised and pathology reports positive margins. Twelve days later, still within the 90-day global period, the same surgeon performs the wider re-excision that was anticipated when the first excision was done. Which modifier applies?

    • A.Modifier 76, because the same surgeon repeated the same kind of excision within the original global period.
    • B.Modifier 78, because the patient came back to the operating room during the global period of the first procedure.
    • C.Modifier 58, because the second procedure was staged or more extensive therapy planned at the time of the first.✓ Answer
    • D.Modifier 79, because the wider excision is a separate service that starts a new global period of its own.

    Modifier 58 covers a procedure during the postoperative period that was planned prospectively at the time of the original surgery, or that is more extensive than the first, or that is therapy following a diagnostic procedure. A re-excision for wider margins after a positive-margin pathology report is the classic staged or more extensive service, not an unplanned complication.

    Source: CPT Appendix A, modifier 58Report a problem with this question

11. 11. Four days after a major operation, and still within its global period, the patient is taken back to the operating room by the same surgeon to control bleeding related to that operation. Which statement is correct?

    • A.Modifier 79 applies, and a fresh global period begins because postoperative bleeding is an unrelated problem.
    • B.Modifier 58 applies, and the original global period keeps running because the return was a planned second stage.
    • C.Modifier 78 applies, and the original global period simply keeps running rather than restarting with this return.✓ Answer
    • D.Modifier 78 applies, and a fresh global period begins on the date the patient returned to the operating room.

    Modifier 78 reports an unplanned return to the operating or procedure room by the same physician for a procedure related to the first one during the postoperative period. Because the return treats a complication of the original surgery rather than a new problem, the payer pays only the intraoperative portion and the original global period continues to run.

    Source: CPT Appendix A, modifier 78; Medicare Claims Processing Manual, Chapter 12, global surgeryReport a problem with this question

12. 12. Thirty days after a right knee arthroscopy that carries a 90-day global period, the same surgeon takes the patient to the operating room to repair a deep laceration of the left hand sustained in a fall at home. Which modifier applies?

    • A.Modifier 79, reporting an unrelated procedure by the same physician during the postoperative period.✓ Answer
    • B.Modifier 24, reporting an unrelated service by the same physician during the postoperative period.
    • C.Modifier 78, reporting an unplanned related procedure requiring a return to the operating room that day.
    • D.Modifier 58, reporting a staged procedure that was planned prospectively at the time of the arthroscopy.

    Modifier 79 is used when the same physician performs a procedure entirely unrelated to the surgery whose global period is still running, and a new global period begins for that unrelated procedure. Modifier 24 expresses the same idea of unrelatedness but is reserved for evaluation and management services, not for procedures.

    Source: CPT Appendix A, modifiers 24 and 79Report a problem with this question

13. 13. A physician assistant assists a surgeon throughout an operation on a Medicare beneficiary. Which modifier does the physician assistant's claim line carry?

    • A.Modifier 82, which identifies an assistant surgeon engaged because a qualified resident surgeon was unavailable.
    • B.Modifier 80, which identifies a physician acting as assistant surgeon throughout the operative session itself.
    • C.Modifier AS, which identifies a physician assistant, nurse practitioner or clinical nurse specialist assisting.✓ Answer
    • D.Modifier SA, which identifies a nurse practitioner rendering the service in collaboration with a physician.

    The 80 series is reserved for physicians acting as assistants at surgery, with 82 covering the case where a qualified resident surgeon is not available. When the assistant is a physician assistant, nurse practitioner or clinical nurse specialist, Medicare requires the HCPCS Level II modifier AS instead.

    Source: CPT Appendix A, modifiers 80 and 82; HCPCS Level II modifier ASReport a problem with this question

14. 14. Two surgeons of different specialties each perform a distinct portion of a single procedure that one code describes, and each dictates a separate operative note for the part he performed. How is the procedure reported?

    • A.Each surgeon reports the same procedure code with modifier 66, identifying a surgical team that performed it.
    • B.Each surgeon reports the same code with modifier 59, since each performed a distinct portion of the procedure.
    • C.Each surgeon reports the same procedure code with modifier 62, identifying the two of them as co-surgeons on the case.✓ Answer
    • D.The primary surgeon reports the code alone and the second reports it with modifier 80 as the assistant surgeon.

    Modifier 62 describes two surgeons working together as primary surgeons, each performing a distinct part of one procedure and each documenting his own work. Modifier 66 is reserved for a surgical team of more than two physicians working with specialized equipment or support personnel, and modifier 80 would wrongly demote one primary surgeon to an assistant.

    Source: CPT Appendix A, modifiers 62 and 66Report a problem with this question

15. 15. An operative note states that the case took far longer and demanded substantially greater effort because of dense adhesions from prior abdominal surgery. What supports appending modifier 22 to the procedure code?

    • A.Documentation showing a second surgeon was called in, since increased work is reported through co-surgery.
    • B.Documentation showing the surgeon spent more than twice the usual time, which is the threshold CPT defines.
    • C.Documentation of a payer preauthorization number obtained before the case for the additional work performed.
    • D.Documentation in the record plus a special report describing the added work and the reason it was required.✓ Answer

    Modifier 22 is reported when the work required is substantially greater than typically required, and CPT instructs that documentation must support the substantial additional work and the reason for it, which payers operationalize as a special report submitted with the claim. CPT sets no fixed time multiple as a threshold, and increased difficulty is not by itself a reason to add a co-surgeon.

    Source: CPT Appendix A, modifier 22 (increased procedural services)Report a problem with this question

16. 16. A surgeon performs a procedure on the patient's right upper eyelid. Which anatomic modifier identifies that site on the claim line?

    • A.Modifier E3, which designates the upper eyelid on the patient's right side of the face.✓ Answer
    • B.Modifier E1, which designates the upper eyelid on the patient's left side of the face.
    • C.Modifier E4, which designates the lower eyelid on the patient's right side of the face.
    • D.Modifier E2, which designates the lower eyelid on the patient's left side of the face.

    The eyelid modifiers run in order from the patient's left to the patient's right: E1 upper left, E2 lower left, E3 upper right and E4 lower right. Using the specific eyelid modifier rather than a bare LT or RT lets the payer see that a later procedure on a different lid is a different site and not a duplicate claim.

    Source: HCPCS Level II anatomic modifiers E1-E4Report a problem with this question

17. 17. During one session a surgeon repairs a tendon of the patient's left thumb and treats a lesion of the patient's left great toe. Which pair of digit modifiers correctly identifies the two sites?

    • A.Modifier F1 for the left thumb and modifier T1 for the left great toe on their respective claim lines.
    • B.Modifier FA for the left thumb and modifier T1 for the left great toe on their respective claim lines.
    • C.Modifier FA for the left thumb and modifier TA for the left great toe on each of their respective claim lines.✓ Answer
    • D.Modifier F5 for the left thumb and modifier T5 for the left great toe on their respective claim lines.

    The digit series both begin with an A for the first digit on the left side: FA is the left thumb with F1 through F4 the remaining left fingers, and TA is the left great toe with T1 through T4 the remaining left toes. F5 and T5 start the right-side sequence, so a left thumb and left great toe are FA and TA.

    Source: HCPCS Level II anatomic modifiers FA, F1-F9 and TA, T1-T9Report a problem with this question

18. 18. An interventional cardiac procedure is performed in the left anterior descending coronary artery of a Medicare beneficiary. Which modifier identifies that vessel on the claim line?

    • A.Modifier LD, which identifies the left anterior descending coronary artery on the claim line.✓ Answer
    • B.Modifier LM, which identifies the left main coronary artery on the submitted claim line.
    • C.Modifier RC, which identifies the right coronary artery on the claim line being submitted.
    • D.Modifier LC, which identifies the left circumflex coronary artery on the submitted claim line.

    The coronary modifiers map one to one onto the named vessels: LD is the left anterior descending, LC the left circumflex, LM the left main and RC the right coronary artery. Reporting the specific vessel matters because interventions in different arteries during the same session are separate services rather than duplicate claim lines.

    Source: HCPCS Level II coronary artery modifiers LC, LD, LM, RCReport a problem with this question

19. 19. Which statement correctly describes HCPCS Level II as compared with CPT?

    • A.It is maintained by CMS and uses one letter with four digits to report supplies, drugs and equipment.✓ Answer
    • B.It is maintained by the AMA and uses five digits to report the physician services that CPT does not describe.
    • C.It is maintained by CMS and uses five digits to report the inpatient procedures that CPT does not describe.
    • D.It is maintained by the AMA and uses one letter with four digits to report state Medicaid-only services.

    HCPCS Level I is CPT, five numeric digits maintained by the AMA, while Level II is maintained by CMS and uses a single letter A through V followed by four digits. Level II exists to report the products, supplies, drugs, durable medical equipment, transportation and certain professional services that CPT does not describe.

    Source: CMS HCPCS Level II coding procedures; HCPCS Level II code structureReport a problem with this question

20. 20. A practice furnishes a Medicare Part B service that it expects will be denied as not reasonable and necessary, but no advance beneficiary notice was obtained before the service. Which modifier and consequence are correct?

    • A.Modifier GX, and because a voluntary notice was issued the beneficiary agreed in advance to be responsible.
    • B.Modifier GZ, and because no advance notice was given the beneficiary cannot be held financially responsible for it.✓ Answer
    • C.Modifier GY, and because the item is excluded by statute the beneficiary is automatically responsible for it.
    • D.Modifier GA, and because a signed notice is on file the beneficiary can be held financially responsible for it.

    Modifier GZ tells the contractor that the item or service is expected to be denied as not reasonable and necessary and that no advance beneficiary notice was signed. Without that signed notice the provider did not transfer liability, so the claim is denied and the beneficiary may not be billed, whereas GA on a signed notice does shift that liability.

    Source: CMS HCPCS modifiers GA, GX, GY, GZ; Medicare Claims Processing Manual, Chapter 30 (ABN, Form CMS-R-131)Report a problem with this question

21. 21. A drug supplied in a single-dose container is given to a Medicare Part B patient, and part of the vial's contents is discarded rather than administered. How is the discarded portion reported?

    • A.Only the administered units, on a single line, with modifier JZ appended to that same claim line.
    • B.The administered units on one line and the discarded units on a second line with modifier JW appended.✓ Answer
    • C.The administered units on one line and the discarded units on a second line with modifier JZ appended.
    • D.Only the full vial's units, on a single line, with modifier KX appended to that same claim line.

    Modifier JW identifies the amount of a drug that was discarded and not administered, reported on its own line so the record accounts for the entire single-dose container. Modifier JZ attests that no amount was discarded, and Medicare requires one or the other on single-dose-container drugs, which is why JZ cannot be used when a remainder was wasted.

    Source: CMS HCPCS modifiers JW and JZ; Medicare Claims Processing Manual, Chapter 17 (discarded drugs)Report a problem with this question

22. 22. A pair of codes appears in the NCCI procedure-to-procedure edit table with a modifier indicator of 0. What does that indicator mean for the coder?

    • A.The edit may be bypassed when an appropriate modifier documents that the two services were distinct.
    • B.The edit no longer applies because it was deleted, so both codes may be reported with no modifier.
    • C.The edit sets a maximum unit count for one code rather than a relationship between two paired codes.
    • D.The edit cannot be bypassed by any modifier, so only the column-one code is reported for that day.✓ Answer

    The NCCI modifier indicator governs whether an edit can be overridden: 0 means no modifier will ever bypass it, 1 means an appropriate modifier may, and 9 means the edit does not apply. Appending 59 or an X{EPSU} modifier to force payment on an indicator-0 pair is unbundling, because the edit reflects a determination that the services are never separately reportable together.

    Source: NCCI Policy Manual, Chapter I; CMS NCCI PTP edit modifier indicators 0, 1, 9Report a problem with this question

Practice questions based on the ICD-10-CM Official Guidelines for Coding and Reporting, the AMA CPT guidelines, the CMS HCPCS Level II system, and federal healthcare compliance law. CPC is a mark of the AAPC and CPT is a mark of the American Medical Association; this site is not affiliated with or endorsed by either. ICD-10-CM, CPT, and HCPCS Level II are revised every year, so these questions test coding rules and conventions rather than code values — always verify actual code selection against the current code books and your payer's published policy. Nothing here is medical, legal, or billing advice. About the CPC exam →