Z Codes: How to know when to include Z codes

Z codes can add valuable information to telling the patient’s story. But extraneous material that is not relevant to the patient’s care should be excluded, unless there is a specific hospital policy to include it.

Often the record for inpatients may list several history codes and there may not be sufficient room in the system to report all these codes. Under what circumstances should they be reported? Is not reporting these codes an error in a retrospective audit? The ICD-10-CM Official Guidelines for Coding and Reporting provides some answers.

UHDDS definition of other diagnoses

Section III of the Guidelines, Reporting Additional Diagnoses cites the UHDDS definition of Other Diagnoses as “all conditions that coexist at the time of admission, that develop subsequently, or that affect treatment received and/or the length of stay. Diagnoses that relate to an earlier episode which have no bearing on the current hospital stay are to be excluded.” This supports the decision to omit codes that are irrelevant to the present condition.

Previous conditions – What is Relevant?

Guideline III. A. provides some additional information on previous conditions. That guideline starts out as: “If the provider has included a diagnosis in the final diagnostic statement, such as the discharge summary or the face sheet, it should ordinarily be coded. Some providers include in the diagnostic statement resolved conditions or diagnoses and status-post procedures from previous admissions that have no bearing on the current stay. Such conditions are not to be reported and are coded only if required by hospital policy.”

Some providers list all past conditions and procedures the patient has experienced, perhaps as part of reviewing older records and copying and pasting this information on all subsequent records. According to this portion of the guidelines, only policies of the individual facility would mandate the inclusion of codes for resolved conditions that do not impact the current encounter. Generally, these codes would not be reported as they do not meet the criteria in the UHDDS definition of other diagnoses.

Impact on current care

Note the last sentence of guideline III.A. that specifically addresses certain Z codes:

“However, history codes (categories Z80-Z87) may be used as secondary codes if the historical condition or family history has an impact on current care or influences treatment.”

For example, if the patient is being treated for pneumonia, and has a personal history of lung cancer, that history code would be relevant and reported. If they also had a history of a cholecystectomy for cholelithiasis, that would not be relevant to this encounter and would not be coded. Similarly for family history codes, if a patient was being evaluated for a cardiac condition, and the patient notes that his father had a myocardial infarction at age 52, a family history code. Z82.49, Family history of ischemic heart disease and other diseases of the circulatory system would be appropriate as it has an impact on the current care.

A review of these guidelines may help clarify when the history codes should and should not be coded.

New course! Now available!
ICD-10-CM: Social Determinants of Health and other Z Codes
In-depth training on accurately capturing factors that influence health status and reasons for encounters across all care settings. Course focuses on the guidelines and conventions governing the use of Z codes.
More info