CPC domain - 36% of the exam

CPT Surgery and Modifiers

CPT Surgery and Modifiers is 36% of the AAPC Certified Professional Coder (CPC) exam. These are the objectives it covers, each with practice questions and worked explanations.

Objectives in this domain

Sample question from this domain

Free sampleCPT Surgery and Modifiersmedium

In a single operative session, one general surgeon performs an open initial inguinal hernia repair (CPT 49505) and, through a separate incision, excises a subcutaneous lipoma of the back measuring 4 cm (CPT 21930). Both are distinct procedures with their own work; the hernia repair carries the higher relative value. How should the coder flag the multiple-procedure relationship on the claim?

CPT 49505 - open repair, initial inguinal hernia, age 5 or older
CPT 21930 - excision, subcutaneous soft tissue tumour, back or flank, 3 cm or greater
  • AAppend modifier 51 to CPT 21930, the lipoma excision Correct
  • BAppend modifier 51 to CPT 49505, the inguinal hernia repair
  • CAppend modifier 59 to CPT 21930, the lipoma excision
  • DAppend modifier 22 to CPT 21930, the lipoma excision
Modifier 51 attaches to the additional, lower-valued procedure when one surgeon performs multiple procedures in the same session. When a single surgeon performs several separately reportable procedures at one session, the highest-valued procedure is billed at full value and each lesser procedure carries modifier 51, which triggers multiple-procedure payment reduction rather than signalling a bundling exception.

Why A is correct: Modifier 51 identifies the additional, lower-valued procedure performed in the same session by the same surgeon, so it belongs on 21930 while the primary 49505 is reported without it.

Why B is wrong: Modifier 51 signals a secondary procedure, but 49505 is the higher-valued primary procedure and stays unmodified; placing 51 on the primary reverses the intended sequencing.

Why C is wrong: Modifier 59 marks a distinct procedural service that would otherwise be bundled by an NCCI edit; these two codes are not an edit pair, so 59 is the wrong tool and 51 is what the multiple-procedure situation calls for.

Why D is wrong: Modifier 22 reports substantially increased work within one procedure, but the note documents two routine procedures, not extraordinary effort on the excision, so 22 is unsupported.

Other domains in this exam

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