2026 ICD-10-CM Diagnosis Code Z85.818Personal history of malignant neoplasm of other sites of lip, oral cavity, and pharynx

ICD-10-CM Codes›Z00–Z99›Z77-Z99›Z85

ICD-10-CM Z85.818
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Z85.818 is a billable ICD-10-CM diagnosis code for personal history of malignant neoplasm of other sites of lip, oral cavity, and pharynx. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 826 through 830, 843 through 845. 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 Personal history of malignant neoplasm.

Code Identity

ICD-10-CM Code
Z85.818
Billable Status
Yes — Valid for Submission
Code Describes
Personal history of malignant neoplasm of other sites of lip, oral cavity, and pharynx
Short Description
Prsnl hx of malig neoplm of site of lip, oral cav, & pharynx
Parent Code
Z85.81
Personal history of malignant neoplasm of lip, oral cavity, and pharynx

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
CategoryZ85Personal history of malignant neoplasm
This CodeZ85.818Personal history of malignant neoplasm of other sites of lip, oral cavity, and pharynx

Code EditsBilling

Medicare Code Editor checks that affect claim validity for Z85.818.

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

Z85.818 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.

  • H/O Malignant melanoma
  • History of cancer of floor of mouth
  • History of carcinoma of lip
  • History of malignant neoplasm of gum
  • History of malignant neoplasm of hypopharynx
  • History of malignant neoplasm of lip
  • History of malignant neoplasm of nasopharynx
  • History of malignant neoplasm of neck
  • History of malignant neoplasm of oral cavity
  • History of malignant neoplasm of oropharynx
  • History of malignant neoplasm of parotid gland
  • History of malignant neoplasm of pharynx
  • History of malignant neoplasm of salivary gland
  • History of malignant neoplasm of tonsil
  • History of nasopharyngeal carcinoma
  • History of primary malignant melanoma of oral mucous membrane
  • History of primary malignant neoplasm of ear, nose and/or throat
  • History of primary malignant neoplasm of oropharynx

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.

    • History
      • personal (of)
        • malignant neoplasm (of)
          • oral cavity
            • specified site NEC
    • History
      • personal (of)
        • malignant neoplasm (of)
          • pharynx
            • specified site NEC

Clinical ClassificationClinical

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

CCSR FAC027
Personal history of malignant neoplasm
Default principal diagnosis: inpatient No · outpatient Yes

Patient EducationClinical

Oral Cancer

Oral cancer is cancer of the mouth. It is a type of head and neck cancer. Most oral cancers are squamous cell cancers. They begin in the flat cells that cover the surfaces of your mouth, tongue, and lips. The cancer cells may spread into deeper tissue as the cancer grows.

The full article covers:

  • What is oral cancer?
  • Who is more likely to develop oral cancer?
  • What are the symptoms of oral cancer?
  • How is oral cancer diagnosed?
  • What are the treatments for oral cancer?
  • Can oral cancer be prevented?

Read the full article at MedlinePlus

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

Convert Z85.818 to ICD-9-CMHistory

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

ICD-9-CM
V10.02 Hx-oral/pharynx malg 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 Z85.818Overview

Is Z85.818 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report personal history of malignant neoplasm of other sites of lip, oral cavity, and pharynx on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does Z85.818 group to?

On inpatient claims, personal history of malignant neoplasm of other sites of lip, oral cavity, and pharynx maps to MS-DRG 826, 827, 828, 829, 830, 843, 844, 845, with relative weights from 0.8516 to 4.6778 depending on complications. Higher weights mean higher Medicare reimbursement.

Can Z85.818 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because personal history of malignant neoplasm of other sites of lip, oral cavity, and pharynx describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

Is Z85.818 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 personal history of malignant neoplasm of other sites of lip, oral cavity, and pharynx on inpatient claims.

What is the ICD-9 equivalent of Z85.818?

Under the General Equivalence Mappings, personal history of malignant neoplasm of other sites of lip, oral cavity, and pharynx converts to ICD-9-CM V10.02 (hx-oral/pharynx malg NEC). The mapping is approximate, so confirm the match fits the documentation.