Medicare Compliance & Reimbursement

Tip: Check out miscellaneous options for treatments that don’t fit into a category.

Z codes are your keys to documenting chronic conditions or underlying physical or social circumstances that can affect a patient’s current health status or treatment. According to the ICD-10-CM chapter guidelines, “Z codes indicate a reason for an encounter.”

The guidelines further explain that codes in the Z00-Z99 range “are provided to deal with occasions when circumstances other than a disease or injury are recorded as diagnosis or problems.” This can happen in two cases: when a provider renders services for a person who may not be sick or when a circumstance that is not a current illness/injury influences a patient’s health status.

ICD-10 classifies Z codes into several general categories, as follows:

1. Contact/Exposure: When a patient has been exposed to a communicable disease or has had contact with a factor hazardous to health, such as Z20.811 (Contact with and [suspected] exposure to meningococcus).

2. Inoculations and vaccinations: When a patient presents for the sole purpose of getting an inoculation, you’d report Z23 (Encounter for immunization).

3. Status: This series indicates that a patient either carries a disease or has the sequelae or residual of past diseases or conditions, such as Z16.11 (Resistance to penicillins).

4. History (of): This demonstrates either a personal history or a family history of a condition or disease, such as Z80.52 (Family history of malignant neoplasm of bladder).

5. Screening: These codes describe the testing to screen for a particular disease or diagnosis, such as those from the Z12.x series (Encounter for screening for malignant neoplasms).

6. Observation: These codes “are for use in very limited circumstances when a person is being observed for a suspected condition that is ruled out,” the ICD-10 manual says. For instance, Z03.89 (Encounter for observation for other suspected diseases and conditions ruled out).

7. Aftercare: These codes describe continued care following the completion of a disease’s healing or recovery phase, such as Z48.290 (Encounter for aftercare following bone marrow transplant).

8. Follow-up: You’ll use follow-up Z codes to explain continuing surveillance after the treatment phase of a disease, condition, or injury is completed. For instance, this series includes Z08 (Encounter for follow-up examination after completed treatment for malignant neoplasm).

9. Donor: These codes are used for living donors of blood or body tissues, such as Z52.89 (Donor of other specified organs or tissues).

10. Counseling: Codes in this category describe counseling for patients or their families following an illness or injury, and include Z71.1 (Person with feared health complaint in whom no diagnosis is made).

11. Encounters for Obstetrical and Reproductive Services: You’d append this type of code for pregnant patients who don’t have problems or complications, such as Z33.1 (Pregnant state, incidental).

12. Newborns and Infants: You’ll report these codes to describe the care of an infant, with options such as Z76.1 (Encounter for health supervision and care of foundling).

13. Routine and Administrative Examinations: These codes allow you to describe encounters for situations such as checkups and pre-employment physicals, and include Z01.818 (Encounter for other preprocedural examination).

14. Miscellaneous Z Codes: Here you’ll find codes for healthcare encounters that don’t fit into the above categories, such as Z57.4 (Occupational exposure to toxic agents in agriculture).

15. Nonspecific Z Codes: These codes are typically limited to situations where the documentation limits more precise coding, and include Z04.9 (Encounter for examination and observation for unspecified reason).

16. Z Codes That May Only Be Principal/First-Listed Diagnosis: You must list the diagnoses in this category as the principal diagnosis unless the patient has multiple encounters on the same date and they are combined. The codes in this category include Z51.11 (Encounter for antineoplastic chemotherapy).