ICD-10-PCS Basics: The Seven Characters

Code sets: FY 2027 ICD-10-PCS.

ICD-10-PCS is the procedure classification for hospital inpatient services. Unlike CPT, you build each code one character at a time from the operative report.

The seven characters (Medical and Surgical section)

1. Section. 0 is Medical and Surgical, which covers most inpatient procedures. Other sections include Obstetrics (1), Placement (2), Administration (3), and Imaging (B).
2. Body system. For example, 0D is the gastrointestinal system.
3. Root operation. The objective of the procedure, such as Excision (B), Resection (T), Drainage (9), or Replacement (R). This is the most important choice you make.
4. Body part. The specific site, such as the sigmoid colon.
5. Approach. How the site was reached: open (0), percutaneous (3), percutaneous endoscopic (4), via natural or artificial opening (7), via natural or artificial opening endoscopic (8), or external (X).
6. Device. Anything left in the body after the procedure; Z means no device.
7. Qualifier. Extra detail, such as diagnostic (X); Z means no qualifier.

How to build a code

1. Read the whole operative report and identify what was actually done.
2. Choose the root operation using the definitions, not the procedure name the surgeon used.
3. Look up the root operation in the Index to find the right table, then build the rest of the code from that table’s row. Every character must come from the same row.

The Index is a starting point; you can go directly to the tables if you know the root operation (FY 2027 ICD-10-PCS Official Guidelines).

Root operations that get confused

• Excision vs. Resection: Excision removes a portion of a body part; Resection removes all of it.
• Drainage vs. Extirpation: Drainage takes out fluids or gases; Extirpation takes out solid matter, such as a clot or stone.
• Replacement vs. Supplement: Replacement takes out the body part and puts in a substitute; Supplement reinforces it without removing it.
• Inspection: coded only when inspection is the whole procedure, not as part of another one.

Study tips

• Learn the definitions of all 31 Medical and Surgical root operations.
• Use the Body Part Key and the Device Key in the back of the book.
• Practice on real operative reports every day; reading speed is what builds accuracy.

Refreshed from the CCO Community archive, November 2026.