HealthAugust 31, 2023

Your guide to ICD-10-CM Z Codes: Don’t sleep on this important data!

This article reviews what ICD-10-CM Z codes are, what are they used for, and how SDoH codes support health equity.

We know “getting our Zzz’s” (sleep) is essential for good health. But did you know Z codes can help contribute positively to our health, as well? We’ve certainly been hearing more and more about Z codes, especially these past few years as we navigated the pandemic. So, what are ICD-10-CM Z codes, what are they used for, and how do they contribute to health and overall well-being?

What are ICD-10-CM Z codes?

Z codes are codes found in Chapter 21: Factors Influencing Health Status and Contact with Health Services (Z00 – Z99) of the ICD-10-CM coding manual. Categories Z00 – Z99 are used in circumstances other than an encounter for a disease, injury, or external cause of morbidity (A00 – Y99). They indicate a reason for an encounter or provide additional information about a patient encounter per the ICD-10-CM Official Guidelines for Coding and Reporting FY2024.

Coding guidelines are followed when assigning ICD-10-CM codes in this chapter. Z codes may be used as either a first listed, or principal diagnosis code in the inpatient setting or a secondary code depending on the circumstances of the encounter. For example, codes in category Z16 “Resistance to antimicrobial drugs” are provided for use as additional codes to identify the resistance and non-responsiveness of a condition to antimicrobial drugs. Guidelines state to code first the infection and then the Z code e.g., Z16.21 Resistance to vancomycin. An example of a principal diagnosis assignment is Z51.11 Encounter for antineoplastic chemotherapy for a patient being admitted for initiation of chemotherapy, followed by the malignant neoplasm code from Chapter 2.

Social determinants of health (SDOH) codes are located primarily in categories Z55 through Z65. We’ll look at these in more detail below, but let’s first peruse the blocks contained in Chapter 21 to get a sense of what Z codes represent:

Z00 - Z13

Persons encountering health services for examinations
Z14 - Z15 Genetic carrier and genetic susceptibility to disease
Z16 Resistance to antimicrobial drugs
Z17 Estrogen receptor status
Z18 Retained foreign body fragments
Z19 Hormone sensitivity malignancy status
Z20 - Z29 Persons with potential health hazards related to communicable diseases
Z30 - Z39 Persons encountering health services in circumstances related to reproduction
Z40 - Z53 Encounters for other specific healthcare
Z55 - Z65 Persons with potential health hazards related to socioeconomic and psychosocial circumstances
Z66 Do not resuscitate status
Z67 Blood type
Z68 Body mass index
Z69 - Z76 Persons encountering health services in other circumstances
Z77 - Z99 Persons with potential health hazards related to family and personal history and certain conditions influencing health status

Social determinants of health (SDoH) Z codes

Now that we have a feel for what Z codes are in general, let’s take a closer look at the codes in Z55 – Z65: Persons with potential health hazards related to socioeconomic and psychosocial circumstances. ICD-10-CM and other standards organizations’ development of SDOH terms is rapidly progressing. The Gravity Project has been integral in moving our nation forward in this work. This diverse, multidisciplinary, collaborative community has successfully introduced a nationally recognized set of consensus-driven standards-based terminologies that support care across multiple social risk domains such as food and transportation insecurity, housing instability, and health literacy. The goal in developing the data standards is to support the collection, use, and exchange of data to address the SDOH across four primary activities of care: screening, diagnosis, goal setting, and interventions. The ICD-10 Z codes fall within the diagnosis activity, which supports the goals for health equity and improving the overall health of people and communities. An example of a code submitted by The Gravity Project is Z59.82 Transportation insecurity. It’s hard to believe a code did not exist previously for this potential barrier as lack of transportation can impact access to care, the obtainment of healthy food, and needed medications, to name a few.

Including SDOH data in the United States Core Data for Interoperability (USCDI) beginning in version 2 supports the ongoing efforts for health equity. ICD-10-CM is included as applicable vocabulary standard, along with SNOMED CT US Edition, in the Problems class with associated data element SDOH Problems/Health Concerns. The other SDOH activities for screening, goals, and interventions are also represented in the USCDI.

Where are Z codes used?

Z codes, in general, can be used in various health settings such as hospitals, physician offices, and skilled nursing facilities. An interesting point about the SDOH-related Z codes classified to chapter 21, such as found in Z55 – Z65, is they can be assigned based on documentation by non-physician clinicians involved in the care of the patient, or from self-reported documentation from the patient, given the information is approved and incorporated into the medical record by a clinician or provider. The American Hospital Association (AHA) Coding Clinic has provided further clarification on the appropriate use and documentation requirements. They state that for the purpose of documenting social information, “clinicians” can include anyone deemed to meet the requirements, set by regulation or internal hospital policy, to document in the patient’s official medical record. This means that in many cases, coding professionals can utilize documentation of social needs from clinicians including, but not limited to, non-physician providers, such as social workers, community health workers, case managers, nurses or other providers.

The information collected at intake through health risk assessments, screening tools, person-provider interaction, and individual self-reporting needs to be captured in the notes. SDOH data may be documented in the problem or diagnosis list, patient or client history, or provider notes. The process of assigning Z codes from the documentation can be guided by the terms matching or mapping. It can be a challenging task to translate billing terms to clinical concepts and vice versa. Terminology service solutions and clinical NLP are two strategies that help in the identification of SDOH data in records and then codify or normalize to standard terminologies such as SNOMED-CT or ICD-10-CM. Further assistance for the assignment of Z codes for encounters is available from the ICD-10-CM Official Guidelines for Coding and Reporting.

Leveraging Z-codes for healthcare analytics

Documenting and codifying the patient story enables interoperability whereby appropriate person-level interventions can be carried out and tracked. Further, analytics at the population or community level can provide insights into care gaps of cohorts and identify solutions that will improve the health of communities.

We believe using Z codes can truly contribute to better health and outcomes. Health Language solutions help healthcare stakeholders create and maintain these patient cohorts for further analysis and action. Learn more about Health Language SDOH value sets and analytics solutions and reach out today to connect with one of our specialists.

Learn More About Social Determinants Of Health
Lisa Wolf Headshot
Lisa Wolf, BSN, RN-BC
Health Language Analytics Integrity
Leverage consistent and accurate datasets to easily derive insights, whether analyzing big data to understand population trends or auditing an individual patient record.
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