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Z28.81 ICD-10-CM Code: Immunization not carried out due to patient having had the disease

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
1 inclusion term · 1 code-also instruction

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43, Appendix B.

  • MS-DRG 795 — NORMAL NEWBORN (MDC 15)
  • MS-DRG 951 — OTHER FACTORS INFLUENCING HEALTH STATUS (MDC 23)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for Z28.81 in the official ICD-10-CM tabular list, quoted as published.

Notes without a marker are published on Z28.81 itself; “inherited from” names the category or block whose note applies here.

Includes

Conditions the official ICD-10-CM tabular list includes under this code.

  • vaccination not carried out

Source: inherited from Z28

Code Also

Additional codes that may be required to fully describe the encounter.

  • Code also, if applicable, encounter for immunization safety counseling (Z71.85)

Source: inherited from Z28

Coder workflow for Z28.81

MedCoder structured workflow — derived from this code’s own official record

Before you code Z28.81

  1. Z28.81’s title joins a condition with an associated condition or complication. Confirm each component is documented. Where the classification presumes the link through the “with” convention, only a provider statement that the conditions are unrelated defeats it. A combination code is assigned only when it fully identifies the documented conditions; a required second code for the stage, type or manifestation is still reported when the notes ask for it (Guidelines I.B.9, I.A.15).

    Guide: Combination codes →

  2. Confirm the reason for the encounter this Z code records: the circumstance it records. Check whether the code may be reported as first-listed or principal — some Z codes are limited to one position — and do not report a history or status code for a condition documented as current. Z code categories and their reporting positions (Guidelines I.C.21.c, I.C.21.c.15).

    Guide: Z codes as principal or first-listed diagnosis →

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
The associated condition or complication
Whether the associated condition the title names is documented; the “with” convention presumes some links, and a provider statement that the conditions are unrelated defeats it (Guidelines I.A.15).
The reason for the encounter
Whether the code records the encounter’s purpose, a status, or a history — and whether it may be first-listed (Guidelines I.C.21.c).

Official instructions as workflow

  • Code Also — related condition(1 note)

    Coding workflow: Review the related condition when both are documented and the instruction applies. A Code Also note does not fix sequencing; the order follows the circumstances of the encounter.

    ReviewZ71.85

    See the official tabular notes · Guidelines I.A.17

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: Only one of the components this code’s title joins is documented.

Coding question: Is Z28.81 supported?

Path: Review the code for the documented component on its own.

Reason: A combination code is assigned only when it fully identifies the documented conditions; otherwise the documented component takes its own code (Guidelines I.B.9).

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Code Overview

Immunization not carried out due to patient having had the disease is a billable ICD-10-CM diagnosis code (Z28.81).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Indexed Clinical Terms (1)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Official Coding Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Verbatim excerpts from the ICD-10-CM Official Guidelines for Coding and Reporting (CMS/NCHS) that govern this code.

Chapter 21: Factors influencing health status and contact with health services (Z00-Z99)

Miscellaneous Z codes/subcategories/categories: Z28 Immunization not carried out Except: Z28.3-, Underimmunization status Z29 Encounter for other prophylactic measures Z40 Encounter for prophylactic surgery Z41 Encounter for procedures for purposes other than remedying health state Except: Z41.9, Encounter for procedure for purposes other than remedying health state, unspecified Z53 Persons encountering health services for specific procedures and treatment, not carried out Z72 Problems related to lifestyle Note: These codes should be assigned only when the documentation specifies that the patient has an associated problem Z73 Problems related to life management difficulty Note: These codes should be assigned only when the documentation specifies that the patient has an associated problem. Z74 Problems related to care provider dependency Except: Z74.01, Bed confinement status Z75 Problems related to medical facilities and other health care Z76.0 Encounter for issue of repeat prescription

Verify Before Coding

  • Principal-diagnosis restriction. The Medicare Code Editor lists this code as unacceptable as a principal diagnosis: it describes a circumstance influencing health status rather than a current illness or injury being treated. It is valid as a secondary diagnosis.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name Z28.81 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Use Additional Code instruction: Z28.3 — Underimmunization status (via Z28.8.-).

These codes instruct coders to additionally report this code when it applies.

Referenced by 1 Code Also instruction: Z71.85 — Encounter for immunization safety counseling (via Z28.-).

These codes suggest coding this condition alongside when both are present.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

Not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity.

Named in the grouper logic of 2 MS-DRGs: DRG 795 (MDC 15), DRG 951 (MDC 23).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):FAC017 — No immunization or underimmunization (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Principal diagnosis restriction (Medicare Code Editor)

Not acceptable as a principal diagnosis on an inpatient claim.

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (No immunization or underimmunization).

Z28.01 — Immunization not carried out because of acute illness of patient, Z28.02 — Immunization not carried out because of chronic illness or condition of patient, Z28.03 — Immunization not carried out because of immune compromised state of patient, Z28.04 — Immunization not carried out because of patient allergy to vaccine or component, Z28.09 — Immunization not carried out because of other contraindication, Z28.1 — Immunization not carried out because of patient decision for reasons of belief or group pressure, Z28.20 — Immunization not carried out because of patient decision for unspecified reason, Z28.21 — Immunization not carried out because of patient refusal, Z28.29 — Immunization not carried out because of patient decision for other reason, Z28.3 — Underimmunization status, Z28.310 — Unvaccinated for COVID-19, Z28.311 — Partially vaccinated for COVID-19, Z28.39 — Other underimmunization status, Z28.82 — Immunization not carried out because of caregiver refusal, Z28.83 — Immunization not carried out due to unavailability of vaccine, Z28.89 — Immunization not carried out for other reason, Z28.9 — Immunization not carried out for unspecified reason

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Immunization”; these codes share that main term but sit in a different category of the Tabular List.

O36.01 — Maternal care for anti-D [Rh] antibodies (Rh factor, affecting management of pregnancy NEC, anti-D antibody), O36.09 — Maternal care for other rhesus isoimmunization (Rh factor, affecting management of pregnancy NEC), P55.1 — ABO isoimmunization of newborn (ABO, in newborn), Z00.121 — Encounter for routine child health examination with abnormal findings (appropriate for age, child, with abnormal findings), Z00.129 — Encounter for routine child health examination without abnormal findings (appropriate for age, child), Z23 — Encounter for immunization (encounter for)

Contextual Map

Every relationship of Z28.81 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run Z28.81 with these 2 related codes in Claim Check

Hierarchy

Referenced by Use Additional Code instructions

  • Z28.3 — Underimmunization status[Use Additional Code](via Z28.8.-): “immunization not carried out for other reason (Z28.8-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Code Also instructions

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

Index entries

  • Immunization, not done (not carried out), because (of), patient had disease being vaccinated against[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (22)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Coding guidelines Official source data
ICD-10-CM Official Guidelines for Coding and Reporting (FY2026), quoted by section Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Immunization not carried out due to patient having had the disease

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to Z28.81 in its code family, with their registry titles.

View all codes in the Z28 family