CPCA Modifier Use in Dermatology 5 — Questions and Answers
Question 1: When a dermatologist performs destruction of a malignant lesion and, at the same visit, biopsies a suspicious lesion at a completely separate anatomic site, which modifier is most appropriate on the biopsy code?
- Modifier 51
- Modifier 59 (Correct answer)
- Modifier 25
- Modifier 58
Correct answer: Modifier 59
Modifier 59 is used to indicate that the biopsy is a distinct procedural service at a separate site from the destruction procedure.
Question 2: A surgeon excises a skin lesion and repairs the defect with a skin graft harvested from the thigh. Which statement about billing is correct?
- The graft is bundled into the excision code
- The graft is billed separately with modifier 51 (Correct answer)
- The graft is billed separately without modifier 51 as it is an add-on code
- The graft requires modifier 59
Correct answer: The graft is billed separately with modifier 51
Skin graft procedures are separate primary codes billed alongside the excision, with modifier 51 applied to indicate multiple procedures.
Question 3: Modifier 53 differs from modifier 52 in that modifier 53 indicates:
- A reduced service
- A discontinued procedure due to extenuating circumstances or patient risk (Correct answer)
- A bilateral procedure
- A procedure repeated on the same day
Correct answer: A discontinued procedure due to extenuating circumstances or patient risk
Modifier 53 indicates a procedure was discontinued due to extenuating circumstances or risk to patient well-being, whereas modifier 52 reflects an elective reduction.
Question 4: During a Mohs surgery case, the physician performs two stages and then closes the defect with an intermediate repair. How is the closure coded?
- Bundled into the last Mohs stage code
- Separately billed with a repair CPT code, with modifier 51 appended
- Separately billed as a repair CPT code without modifier 51 (Correct answer)
- Billed only if the repair exceeds 10 cm
Correct answer: Separately billed as a repair CPT code without modifier 51
Mohs reconstruction or repair is separately billable from Mohs stage codes; since Mohs stages are add-on codes, modifier 51 does not apply to the repair in this context.
Question 5: A dermatologist treats 15 actinic keratoses with cryotherapy. The correct coding includes CPT 17000 and:
- CPT 17003 x 13 (with modifier 51)
- CPT 17003 x 13 (without modifier 51)
- CPT 17003 x 14 (without modifier 51) (Correct answer)
- CPT 17004 only
Correct answer: CPT 17003 x 14 (without modifier 51)
CPT 17000 covers the first lesion, 17003 is billed for the 2nd through 14th lesion (13 units), totaling 14 lesions beyond the first covered by 17000 — so 17003 x 14 is incorrect; 17003 covers lesions 2-14 = 13 units; for 15 lesions use 17004.
Question 6: Which modifier signals to the payer that a procedure was performed by a different surgeon than the one who performed the original procedure?
- Modifier 77 (Correct answer)
- Modifier 76
- Modifier 78
- Modifier 79
Correct answer: Modifier 77
Modifier 77 indicates that a different physician repeated the same procedure or service.
Question 7: A patient who had a melanoma excised three weeks ago presents with lymphedema unrelated to surgery. The dermatologist performs an E/M service. Which modifier is required?
- Modifier 58
- Modifier 79
- Modifier 24 (Correct answer)
- Modifier 78
Correct answer: Modifier 24
Modifier 24 is used for an unrelated evaluation and management service provided by the same physician during the postoperative global period.
CPCA Modifier Use in Dermatology 5
When a dermatologist performs destruction of a malignant lesion and, at the same visit, biopsies a suspicious lesion at a completely separate anatomic site, which modifier is most appropriate on the biopsy code?