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  5. Resistance to antimicrobial drugs (Z16)

Resistance to antimicrobial drugs (Z16)

ICD-10 code range Z16 is specifically used to identify different types of resistance to antimicrobial drugs. These codes help document cases where bacteria or other microbes are resistant to antibiotics, antifungals, antivirals, or antiparasitic agents, which is critical for effective treatment planning and infection control.

This code chapter covers resistance to diverse drugs, including beta lactam antibiotics (Z16.1) like penicillins (Z16.11) and extended spectrum beta lactamase producing bacteria (Z16.12), which are often called "Beta lactam resistant bacterial infections." It also includes resistance to powerful antibiotics such as carbapenems (Z16.13, Z16.19) and vancomycin (Z16.21) used for severe infections, plus resistance to quinolones and fluoroquinolones (Z16.23) common in treating tuberculosis and other bacterial infections. Codes like Z16.24 and Z16.35 cover cases of multidrug resistance, highlighting infections by multi drug resistant bacteria or Acinetobacter. Resistance to antifungal (Z16.32) or antiviral drugs (Z16.33) is similarly addressed. Antimycobacterial drug resistance is detailed with codes for single (Z16.341) and multiple drug resistance (Z16.342), important for documenting antibiotic resistant tuberculosis. This granularity supports accurate clinical documentation of drug resistance patterns crucial for patient care and public health.

Instructional Notations

Code First

Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.

  • the infection

Type 1 Excludes

A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.

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

  • 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.

Clinical Terms

The following clinical terms provide additional context, helping users better understand the clinical background and common associations for each diagnosis listed in this section. Including related terms alongside ICD-10-CM codes supports coders, billers, and healthcare professionals in improving accuracy, enhancing documentation, and facilitating research or patient education.

Drug Resistance

Diminished or failed response of an organism, disease or tissue to the intended effectiveness of a chemical or drug. It should be differentiated from DRUG TOLERANCE which is the progressive diminution of the susceptibility of a human or animal to the effects of a drug, as a result of continued administration.

Drug Resistance, Bacterial

The ability of bacteria to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).

Drug Resistance, Fungal

The ability of fungi to resist or to become tolerant to chemotherapeutic agents, antifungal agents, or antibiotics. This resistance may be acquired through gene mutation.

Drug Resistance, Microbial

The ability of microorganisms, especially bacteria, to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).

Drug Resistance, Multiple

Simultaneous resistance to several structurally and functionally distinct drugs.

Drug Resistance, Multiple, Bacterial

The ability of bacteria to resist or to become tolerant to several structurally and functionally distinct drugs simultaneously. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).

Drug Resistance, Multiple, Fungal

The ability of fungi to resist or to become tolerant to several structurally and functionally distinct drugs simultaneously. This resistance phenotype may be attributed to multiple gene mutations.

Drug Resistance, Multiple, Viral

The ability of viruses to resist or to become tolerant to several structurally and functionally distinct drugs simultaneously. This resistance phenotype may be attributed to multiple gene mutation.

Drug Resistance, Neoplasm

Resistance or diminished response of a neoplasm to an antineoplastic agent in humans, animals, or cell or tissue cultures.

Drug Resistance, Viral

The ability of viruses to resist or to become tolerant to chemotherapeutic agents or antiviral agents. This resistance is acquired through gene mutation.

Drug Tolerance

Progressive diminution of the susceptibility of a human or animal to the effects of a drug, resulting from its continued administration. It should be differentiated from DRUG RESISTANCE wherein an organism, disease, or tissue fails to respond to the intended effectiveness of a chemical or drug. It should also be differentiated from MAXIMUM TOLERATED DOSE and NO-OBSERVED-ADVERSE-EFFECT LEVEL.