Cellulitis ICD-10-CM codes

Category L03 is built on site. The 4th character picks the region (finger and toe, other parts of limb, face and neck, trunk, other sites), the 5th character narrows it (cellulitis versus acute lymphangitis, then a specific area), and limb codes take a 6th character for laterality. Lower leg cellulitis, the most common presentation, is L03.115 (right) or L03.116 (left). L03.90 (cellulitis, unspecified) is only correct when the record gives no site at all; a documented site with no side goes to the unspecified-laterality option such as L03.119.

L03 carries a use-additional-code note for the infectious agent (B95 to B97). Add B95.61 for MSSA, B95.62 for MRSA, B95.0 for group A strep, or B96.20 for E. coli when cultures identify the organism. Do not add Z16.11 for MRSA: the B95.62 code already conveys methicillin resistance. Cellulitis with a documented abscess at the same site is reported with both the L03 code and the matching L02 abscess code.

When cellulitis complicates an open wound, code the injury (an S-code with the appropriate 7th character) together with the L03 code; which one is sequenced first depends on the reason for the encounter. If the provider documents sepsis due to cellulitis, sequence the sepsis code (A41.9, or A41.01 or A41.02 for staph) first and the L03 code second. Postprocedural cellulitis of a surgical site is coded to T81.4- rather than L03.