ICD-10 Code for Postoperative Wound Infection
The ICD-10 code for postoperative wound infection is T81.4 (Infection following a procedure). 1
Primary Coding
- Use T81.4 as the primary code when clinical signs of surgical site infection are present, including erythema and purulent or serous drainage from the wound 1
- This code applies to infections occurring within 30 days after surgery involving the skin, subcutaneous tissue, or deeper tissues 2
Clinical Documentation Requirements for Accurate Coding
To support proper coding with T81.4, your clinical documentation should include: 1
- Presence and extent of erythema (with measurements)
- Character of drainage (purulent, serous, or serosanguineous)
- Associated local signs (warmth, tenderness, induration)
- Systemic signs (fever, elevated white blood cell count)
- Gram stain and culture results when obtained
Timing Considerations
- Infections appearing after 96 hours postoperatively are more likely to represent true infection and warrant the T81.4 code 1
- Fever and wound changes in the first 48-72 hours typically represent non-infectious inflammatory responses rather than true infection 1
- The rare exceptions are group A streptococcal or clostridial infections, which can occur within the first 48 hours 1
Additional Coding Considerations
When applicable, consider adding: 1
- Organism-specific codes if MRSA is suspected or confirmed
- Polymicrobial infection codes for wounds of the perineum or operations involving the GI tract or female genital tract
- Separate procedure codes for suture removal plus incision and drainage when performed
Common Pitfalls to Avoid
- Do not code early postoperative inflammation (first 48-72 hours) as infection unless there is clear evidence of group A streptococcal or clostridial infection 1
- The wound classification (clean, clean-contaminated, contaminated, dirty) should be reflected in your clinical documentation to support the infection diagnosis 1
- The positive predictive value of T81.4 coding is approximately 35%, so ensure clinical documentation clearly supports the diagnosis 3