MRSA Infection ICD-10-CM codes

MRSA coding depends on whether the infection has a site-specific code. When the infection is documented only as MRSA with no localized site, assign A49.02 (MRSA infection, unspecified site). When there is a localized infection with its own code, such as cellulitis (L03.-), osteomyelitis (M86.-), or a wound infection, code the site first and add B95.62 (MRSA as the cause of diseases classified elsewhere) to identify the organism.

Some conditions have combination codes that already include MRSA and do not need B95.62: J15.212 for MRSA pneumonia and A41.02 for MRSA sepsis. The methicillin susceptible (MSSA) parallels are A49.01, B95.61, J15.211, and A41.01. Because these codes already state methicillin resistance, do not add Z16.11 (resistance to penicillins) to any MRSA code; Z16.11 is reserved for other organisms with documented penicillin resistance.

Colonization is not infection. A positive nasal swab in a patient with no active infection is Z22.322 (carrier or suspected carrier of MRSA), and Z22.321 is the MSSA equivalent. A colonized patient who also has an active MRSA infection gets both the infection code and Z22.322. Once the infection has resolved, report Z86.14 (personal history of MRSA infection) on subsequent encounters when it is relevant.