2026 ICD-10-CM Diagnosis Code Z90.09Acquired absence of other part of head and neck

ICD-10-CM Codes›Z00–Z99›Z77-Z99›Z90

ICD-10-CM Z90.09
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Z90.09 is a billable ICD-10-CM diagnosis code for acquired absence of other part of head and neck. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is not accepted as a principal diagnosis by the Medicare Code Editor and exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Acquired absence of limb or organ.

Code Identity

ICD-10-CM Code
Z90.09
Billable Status
Yes — Valid for Submission
Code Describes
Acquired absence of other part of head and neck
Short Description
Acquired absence of other part of head and neck
Same as the full description in the CMS dataset.
Parent Code
Z90.0
Acquired absence of part of head and neck

Code Classification

ChapterZ00–Z99Factors influencing health status and contact with health services
SectionZ77-Z99Persons with potential health hazards related to family and personal history and certain conditions influencing health status
CategoryZ90Acquired absence of organs, not elsewhere classified
This CodeZ90.09Acquired absence of other part of head and neck

Code EditsBilling

Medicare Code Editor checks that affect claim validity for Z90.09.

Unacceptable principal diagnosis
There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.

Present on Admission (POA)Billing

Z90.09 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Absence of bilateral tonsils
  • Absence of ear
  • Absent adenoids
  • Acquired absence of nose
  • History of excision of endocrine gland
  • History of subtotal thyroidectomy
  • History of thyroid lobectomy
  • History of thyroidectomy
  • History of tonsillectomy
  • History of vitrectomy
  • Tonsil absent

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Acquired absence of nose

Type 2 Excludes

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Absence(of) (organ or part) (complete or partial)
      • head, part (acquired) NEC
    • Absence(of) (organ or part) (complete or partial)
      • nose (congenital)
        • acquired

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR FAC022
Acquired absence of limb or organ
Default principal diagnosis: inpatient No · outpatient Yes

Patient EducationClinical

Head Injuries

Chances are you've bumped your head before. Often, the injury is minor because your skull is hard and it protects your brain. But other head injuries can be more severe, such as a skull fracture, concussion, or traumatic brain injury.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert Z90.09 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
V45.79 Acq absence of organ NEC
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About Z90.09Overview

Is Z90.09 (Acquired absence of part of head and neck) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report acquired absence of other part of head and neck on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Can Z90.09 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because acquired absence of other part of head and neck describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

Is Z90.09 exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for acquired absence of other part of head and neck on inpatient claims.

What is the ICD-9 equivalent of Z90.09?

Under the General Equivalence Mappings, acquired absence of other part of head and neck converts to ICD-9-CM V45.79 (acq absence of organ NEC). The mapping is approximate, so confirm the match fits the documentation.