What You Should Know About Z Codes

Prior to the emergence of ICD-10 diagnosis codes in late 2015, clinicians used ICD-9 “E” codes to describe external causes of injuries and poisonings, and “V” codes to detail when circumstances other than a disease or injury resulted in an encounter and were noted by providers as problems or factors that influence care. Under ICD-10, many of these codes fall into the “Z” code category. Most podiatrists did not use the “E” and “V” codes often or at all. However, I do believe we should apply the “Z” codes, when appropriate, to our documentation and resultant claims.

One can find the Z codes in Chapter 21 (Factors Influencing Health Status and Contact with Health Services (Z00-Z99)) of the ICD-10-CM code book.¹ Clinicians may apply Z codes in any health care setting, such as the office, a hospital or in a nursing facility.¹ The online ICD-10-CM “Guidelines for Coding and Reporting” advise providers to code for all coexisting comorbidities, especially those part of medical decision-making (MDM).²  

There are 16 categories of Z codes. Those items I have starred, in my opinion, represent areas of potential interest for podiatric physicians for further evaluation.

• *Contact/Exposure – These are circumstances in which the patient has come in contact with, or has been exposed to, either a communicable disease or another issue that is hazardous to his or her health.²
• Inoculations and vaccinations – This indicates that a patient encounter is for an inoculation or a vaccination. It is not the same as the procedure code for the administration of the actual vaccination.²
• *Status – These codes illustrate when a patient is either a carrier of a disease or has sequelae of a previous condition. It is not the same as “history,” as for these purposes, that suggests the patient no longer has the condition. For podiatric purposes, examples may include “retained foreign body fragments” or “acquired absence of limb.”²
• *History (of) – As I stated previously, these codes indicate when a patient used to have a certain relevant condition but does not have it any more, or, when there is a family history of a condition that warrants monitoring. Pertinent examples include personal “history of falling” or “family history of primary malignant neoplasm.”²
• *Screening – This indicates that a screening exam is planned to assist in early detection of a given condition.²
• *Observation – These are rarely used codes for observation or evaluation of conditions that have been ruled out, and when symptoms/diagnoses related to the condition do not apply.²
• *Aftercare – Clinicians may use these codes when aftercare or subsequent treatment is necessary during recovery or due to long-term consequences of a condition. There are specific codes relating to reconstruction after a surgery, fitting or adjustment of a prosthesis, adjustment/management of an implanted device and orthopedic aftercare among others.²
• *Follow-up – These codes refer to situations in which providers use follow-up visits for surveillance of a condition that no longer exists, such as in previous malignant neoplasm and postpartum care.²
• Donor – This indicates when a living individual is donating blood or body tissue for others.²
• *Counseling – This applies to when a patient or family member receives support or counseling due to an illness, injury or other family or social issue. Examples include but are not limited to genetic counseling, childbirth instruction or mental health services for victims of abuse.²
• Encounters for obstetrical and reproductive services²
• Newborns and infants – This mostly refers to child health examinations in the very young.²
• *Routine and administrative examinations - These most typically apply to routine physicals and pre-employment physicals.²
• *Miscellaneous Z codes – Some pertinent codes for podiatrists in this category apply to problems associated with education/literacy, employment or unemployment, physical environment, housing/economic circumstances, social environment or psychosocial circumstances. There is also a code (Z91.1-) that applies to “patient noncompliance with medical treatment and regimen.”²
• *Nonspecific Z codes – These rarely apply and one would only use them in circumstances when documentation does not support more precise/accurate coding.²

Clinicians can report some Z codes as a primary diagnosis. ICD-10-CM guidelines list which Z codes are reportable only as the first listed diagnosis.² However, most often, providers would be using the Z codes along with a primary diagnosis code that describes the illness or injury. As the Z code falls under the category labeled “Factors influencing health status and contact with health services,” applying these Z codes correctly would improve claims accuracy and specificity, and help establish medical necessity for treatment. As status codes may affect the course of treatment and its outcome, one may also employ these codes to track public health issues.

When Patients Have Conditions Related To Natural Disasters

The Centers for Disease Control and Prevention (CDC) also offers coding guidance linked to current events on its website. For example, earlier this year, the CDC documented a reminder on how to assign X and Z codes for patients needing treatment for conditions connected to hurricanes. Clinicians who practice in areas more prone to natural disasters such as hurricanes may want to check the resources available on the CDC website.³

The Importance Of Z Codes: Looking To The Future

As we move deeper into the Merit-based Incentive Payment System (MIPS) program, outcomes and costs related to our services will be scrutinized further. I contend that using Z codes to report patients not following instructions, not taking medications as prescribed or skipping dosing (which can affect the outcome and their medical status) helps to show the thorough care and follow up we provide. This is also true when we include Z codes for things such as long-term use of insulin (Z79.4).

I have often received questions regarding the use of evaluation and management services or follow-up care along with a procedure, such as wound care. Here is where a Z code may describe why the patient’s medical status worsened. If you had to change your plan, this would hopefully justify the medical necessity for further workup and increased decision making along with the care of the wound (debridement) on that particular day. It just helps to paint the picture of what happened to our patient and the work we put into treating the patient the best way.

Dr. Aung is Chief of the Podiatry Section of the Tenet Health System/St. Joseph’s Hospital and a Panel Physician at Tenet Health System/St. Mary’s Hospital Outpatient Wound and Hyperbaric Center in Tucson, Ariz. She is a member of the APMA Coding Committee, the APMA MACRA/MIPS Task Force and is on the Exam Committee of the American Board of Wound Management. Her website is www.healthy-feet.com.

References

1. ICD-10-CM 2019: The Complete Official Codebook. American Medical Association Press; 2018.
2. ICD-10-CM Official Guidelines For Coding And Reporting FY 2019 (October 1, 2018 - September 30, 2019). Centers for Medicare and Medicaid Services. Available at: https://www.cms.gov/Medicare/Coding/ICD10/Downloads/2019-ICD10-Coding-Guidelines-.pdf Accessed October 1, 2019.
3. Centers for Disease Control. Available at: www.cdc.gov. Accessed October 14, 2019.