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Take a Stab at Reporting COVID-19 Vaccination Status

Take a Stab at Reporting COVID-19 Vaccination Status

Know which codes to turn to when a patient isn’t fully vaccinated.

Over the past two years, we’ve seen the inception and evolution of codes and guidelines for reporting COVID-19 and its associated diagnostic, therapeutic, and preventive measures. Notably, the fiscal year (FY) 2022 update to ICD-10-CM includes a significant code addition for COVID-19 underimmunization status. Effective April 1, 2022, the Centers for Disease Control and Prevention’s (CDC’s) National Center for Health Statistics (NCHS) implemented three new diagnosis codes. When a patient is unvaccinated or partially vaccinated for COVID-19, you will report Z28.310 Unvaccinated for COVID-19, Z28.311 Partially vaccinated for COVID-19, or Z28.39 Other underimmunization status. (Z28.3 Underimmunization status was deleted.)

Appropriate documentation and accurate reporting are crucial for clinician communication and tracking of individuals who are not fully vaccinated for COVID-19. Let’s take a closer look at proper use and application of the three added codes.

Vaccination and Data Collection Are Crucial

COVID-19 is the disease caused by SARS-CoV-2, the novel coronavirus that has spread worldwide. While most people with COVID-19 experience mild to moderate symptoms, some become critically ill. Luckily, COVID-19 vaccines, which can protect anyone against this highly communicable disease, are widely available in the United States. Their utilization is critical to ending the COVID-19 pandemic. Available COVID-19 vaccines have been studied and proven effective at protecting people against severe illness, hospitalization, and even dying. The CDC highly recommends that everyone 5 years of age and older get the primary series of COVID-19 vaccinations and receive a booster dose(s) when eligible.

According to the ICD-10 Coordination and Maintenance Committee Meeting held Sept. 14-15, 2021, immunization provides great protection and reduces the risk of serious illness from COVID-19, and tracking people who are not immunized or only partially immunized provides significant modifiable risk factors for morbidity and mortality. This data is of interest for clinical reasons as well as for the value it brings to public health.

Employ New Codes and Guidance

The new ICD-10-CM codes Z28.310, Z28.311, and Z28.39 are located in Chapter 21: Factors Influencing Health Status and Contact with Health Services (Z00-Z99). Physicians and coding professionals should report these codes for patient underimmunization COVID-19 status cases in which the patient is unvaccinated for COVID-19, partially vaccinated for COVID-19, or falls under other underimmunization status.

In the updated 2022 ICD-10-CM Official Guidelines for Coding and Reporting, effective April 1, new Section I.C.1.g.1.n provides guidance regarding the use of the new ICD-10-CM codes. It specifies to report code Z28.310 for a patient who has not received at least one dose of any COVID-19 vaccine. Report code Z28.311 for a patient who has received at least one dose of a multi-dose COVID-19 vaccine regimen but has not received the recommended set of doses necessary to meet the CDC’s definition of “fully vaccinated” at the time of the patient encounter. And report code Z28.39 for a patient who is considered underimmunized or not current on other non-COVID vaccines required for their stated age. Do not use Z28.39 to report a patient’s COVID-19 vaccination status.

According to the CDC, “A person is fully vaccinated two weeks after receiving all recommended doses in the primary series of their COVID-19 vaccination. A person is up to date with their COVID-19 vaccination if they have received all recommended doses in the primary series and one booster when eligible. Getting a second booster is not necessary to be considered up to date at this time.”

This means, as of April 1, if the provider’s documentation includes information on the patient’s COVID-19 vaccination status, you will report Z28.310 or Z28.311 as appropriate. An additional code may be assigned for other reasons, if applicable, such as contraindication (Z28.0-), patient’s belief or group pressure (Z28.1), or patient’s decision for other and unspecified reason (Z28.2-). In the 2022 ICD-10-CM Tabular List, the following noteworthy information is added:

Z28.3 Underimmunization status

  • Use additional code, if applicable, to identify:
    • Immunization not carried out because of contraindication (Z28.0-)
    • Immunization not carried out because of patient decision for other and unspecified reason (Z28.2-)
    • Immunization not carried out because of patient decision for reasons of belief or group pressure (Z28.1)
    • Immunization not carried out for other reason (Z28.8-)

Z28.31 Underimmunization for COVID-19 status

  • Note: These codes should not be used for individuals who are not eligible for the COVID-19 vaccines, as determined by the healthcare provider.

Z28.310 Unvaccinated for COVID-19

Z28.311 Partially vaccinated for COVID-19

Z28.39 Other underimmunization status

  • Delinquent immunization status
  • Lapsed immunization schedule status

Now let’s practice this coding with a case scenario.

Practice Coding for  COVID-19 Underimmunization Status

A 31-year-old male was seen in the provider’s office for shortness of breath. The provider documented in the discharge note that the patient had pneumothorax and although eligible, refuses to be immunized against COVID-19. How is this coded?


J93.83         Other pneumothorax

Z28.310 Unvaccinated for COVID-19

Z28.21         Immunization not carried out because of patient refusal

Rationale: Assign code J93.83 as the principal diagnosis, followed by Z28.310 for the patient’s COVID-19 underimmunization status and Z28.21 to report the reason the patient is not getting immunized against COVID-19. In this case, the provider documentation states that the patient has not been immunized against COVID-19, even though he is eligible, and specifies the patient’s reason in the medical record. According to new guideline I.C.1.g.1.n, code Z28.310 is assigned for a patient who has not received at least one dose of any COVID-19 vaccine. And under category Z28.3, you’re instructed to use an additional code, if applicable, to identify the reason for not being immunized.

All healthcare professionals and practices will benefit from reviewing the new codes added and the revised guideline for FY 2022. The Centers for Medicare & Medicaid Services (CMS) released the 2022 ICD-10-CM Official Guidelines for Coding and Reporting on July 12, 2021, and updated them on Feb. 1, 2022. ICD-10-CM 2022 codes and guidelines are effective Oct. 1, 2021, through Sept. 30, 2022, unless otherwise stated.


ICD-10-CM Official Guidelines for Coding and Reporting, FY 2022 updated April 1, 2022,

ICD-10-CM 2022 Addendum – updated Feb. 1, 2022, and
ICD-10-CM 2022 code tables, Tabular List and Alphabetic Index – updated Feb. 1, 2022,

ICD-10 Coordination and Maintenance Committee Meeting, page 194, Sept. 14-15, 2021,

Stay Up to Date with Your Vaccines, (updated April 2, 2022)

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Artemio Castillejos
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Artemio Castillejos, CPC, CPMA, CCVTC, AAPC Approved Instructor, CCS, LSS-GB, LFC, is a healthcare professional, AAPC Philippine local chapter officer, approved AAPC CEU education provider, AHIMA World Congress board member, and AHIMA PCAP council reviewer with more than eight years of extensive experience in auditing, training, education, compliance, and coding both Australian and American Coding Classification Systems. He is a training manager in the medical coding department at PMAX Global, Philippines. Castillejos specializes in cardiology, cardiothoracic and vascular surgery, evaluation and management, ambulatory surgery coding, pain management, orthopedics, pulmonary, internal medicine, anesthesiology, emergency medicine, and denial management.

One Response to “Take a Stab at Reporting COVID-19 Vaccination Status”

  1. L. D. Lewis says:

    Great article and resources. Thank you

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