Z16.23 Resistance to quinolones and fluoroquinolones

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applies from Z16 Resistance to antimicrobial drugs

Excludes1 (never code together)

• Methicillin resistant Staphylococcus aureus infection (A49.02)
• Methicillin resistant Staphylococcus aureus pneumonia (J15.212)
• Sepsis due to Methicillin resistant Staphylococcus aureus (A41.02)

Code first

• the infection

Notes

• The codes in this category are provided for use as additional codes to identify the resistance and non-responsiveness of a condition to antimicrobial drugs.

MS-DRG index

Defines the logic of DRG(s) 867-869 in MDC 18.

Approximate ICD-9-CM (GEMs)

• V09.50 Infection with microorganisms without mention of resistance to multiple quinolones and fluroquinolones (approximate)
• V09.51 Infection with microorganisms with resistance to multiple quinolones and fluroquinolones (approximate)

Medicare Code Edits (MCE v43.1 (April 2026))

• Unacceptable principal diagnosis: These codes describe a circumstance which influences care but is not a current illness or injury, or capture only an underlying condition, and are unacceptable as principal diagnosis.

Code annotations containing back-references to Z16.23

Back-references to Z16.2

• Type 1 Excludes: Z16.3 Resistance to other antimicrobial drugs ("resistance to antibiotics (Z16.1-, Z16.2-)")

Diagnosis Index entries for Z16.23

• Resistance, resistant (to) › organism (s) › to › drug › fluoroquinolones
• Resistance, resistant (to) › organism (s) › to › drug › quinolones

Nearby codes

• Z16.19 Resistance to other specified beta lactam antibiotics
• Z16.2 Resistance to other antibiotics
• Z16.20 Resistance to unspecified antibiotic
• Z16.21 Resistance to vancomycin
• Z16.22 Resistance to vancomycin related antibiotics
• Z16.23 Resistance to quinolones and fluoroquinolones (this code)
• Z16.24 Resistance to multiple antibiotics
• Z16.29 Resistance to other single specified antibiotic
• Z16.3 Resistance to other antimicrobial drugs
• Z16.30 Resistance to unspecified antimicrobial drugs
• Z16.31 Resistance to antiparasitic drug(s)