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C12 ICD-10-CM Code: Malignant neoplasm of pyriform sinus

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

Coding at a Glance

Tabular directives
1 inclusion term · 7 use-additional codes
Risk adjustment
CMS-HCC V28: 1 category · CMS-HCC V22 category 11

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 v44, Appendix B.

  • MS-DRG 011 — TRACHEOSTOMY FOR FACE, MOUTH AND NECK DIAGNOSES OR LARYNGECTOMY WITH MCC (MDC PRE)
  • MS-DRG 012 — TRACHEOSTOMY FOR FACE, MOUTH AND NECK DIAGNOSES OR LARYNGECTOMY WITH CC (MDC PRE)
  • MS-DRG 013 — TRACHEOSTOMY FOR FACE, MOUTH AND NECK DIAGNOSES OR LARYNGECTOMY WITHOUT CC/MCC (MDC PRE)
  • MS-DRG 146 — EAR, NOSE, MOUTH AND THROAT MALIGNANCY WITH MCC (MDC 03)
  • MS-DRG 147 — EAR, NOSE, MOUTH AND THROAT MALIGNANCY WITH CC (MDC 03)
  • MS-DRG 148 — EAR, NOSE, MOUTH AND THROAT MALIGNANCY WITHOUT CC/MCC (MDC 03)

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.

Risk Adjustment (CMS-HCC)

Payment categories this diagnosis maps to under CMS-HCC V28, payment year 2026.

  • HCC 21 — Lymphoma and Other Cancers (supersedes HCC 22, HCC 23)

Other models: CMS-HCC V22 HCC 11

Risk scores depend on the enrollee's full accepted diagnosis set and segment; a category mapping alone does not determine payment.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for C12 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2027Effective: October 1, 2026

Trace:FY2027 changesChange historyRelease, file and checksum

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Malignant neoplasm of pyriform fossa

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • Use additional code to identify:
  • exposure to environmental tobacco smoke (Z77.22)
  • exposure to tobacco smoke in the perinatal period (P96.81)
  • history of tobacco dependence (Z87.891)
  • occupational exposure to environmental tobacco smoke (Z57.31)
  • tobacco dependence (F17.-)
  • tobacco use (Z72.0)

Coder workflow for C12

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

Before you code C12

  1. Confirm the documented site and behavior (this code’s block classifies malignant neoplasms), whether the site is primary or secondary, and whether the malignancy is current or a personal history: a previously excised malignancy with no further treatment and no evidence of disease is history, not current disease. Verify the site against the Table of Neoplasms. Neoplasm chapter guidelines (Guidelines I.C.2.a, I.C.2.d, I.C.2.m).

    See the Table of Neoplasms entries · Guide: Active cancer vs history of cancer →

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).
Anatomical site
At the most specific level the record states; a site the classification separates cannot be assumed from a procedure or a measurement.
The conditions the Use Additional Code note names
Reported with this code when documented; a conditional instruction (“if applicable”, “if known”) applies only when the record supports it.
Behavior and current-versus-history status
Malignant, in situ, benign or uncertain; primary or secondary; current disease or personal history (Guidelines I.C.2.m).

Official instructions as workflow

  • Use Additional Code — after identifying C12(7 notes)

    Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with C12 when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.

    ReviewZ77.22, P96.81, Z87.891, Z57.31, F17, Z72.0

    See the official tabular notes · Guidelines I.A.13

Coding decision scenarios

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

Documentation: A condition the Use Additional Code note names is documented.

Coding question: Is a second code reported with C12?

Path: Review the Use Additional Code note and the code it names.

Reason: The additional code is reported when the record documents the condition; a conditional instruction applies only when its condition is met (Guidelines I.A.13).

ReviewZ77.22, P96.81, Z87.891, Z57.31, F17, Z72.0

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.

Coding context

The comparisons, hierarchy, index entries, guidelines, relationships, risk-adjustment and coverage context a coder commonly needs. Each section names whether it is official source data, a MedCoder-derived relationship or MedCoder editorial.

Code Overview

Malignant neoplasm of pyriform sinus is a billable ICD-10-CM diagnosis code (C12).

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

Neoplasm Table Sites (6)

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

Anatomical sites from the official ICD-10-CM Table of Neoplasms that map to this code, with the matching behavior column.

  • Neoplasm, neoplastic, fossa (of), piriform — Malignant, Primary
  • Neoplasm, neoplastic, fossa (of), pyriform — Malignant, Primary
  • Neoplasm, neoplastic, hypopharynx, hypopharyngeal NEC, pyriform fossa (sinus) — Malignant, Primary
  • Neoplasm, neoplastic, piriform fossa or sinus — Malignant, Primary
  • Neoplasm, neoplastic, pyriform fossa or sinus — Malignant, Primary
  • Neoplasm, neoplastic, sinus (accessory), pyriform — Malignant, Primary

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

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 C12 or its code family, from the CMS ICD-10-CM tabular instructional notes and the CMS Table of Neoplasms. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes2 note: C13 — Malignant neoplasm of hypopharynx.

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

Referenced by 5 Same-site neoplasm codes: C79.89 — Secondary malignant neoplasm of other specified sitesCompare C12 vs C79.89 →, D00.08 — Carcinoma in situ of pharynxCompare C12 vs D00.08 →, D10.7 — Benign neoplasm of hypopharynxCompare C12 vs D10.7 →, D37.05 — Neoplasm of uncertain behavior of pharynxCompare C12 vs D37.05 →, D49.0 — Neoplasm of unspecified behavior of digestive systemCompare C12 vs D49.0 →.

These codes represent related neoplasm behaviors affecting the same anatomic site.

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.

Named in the grouper logic of 6 MS-DRGs: DRG 011 (MDC PRE), DRG 012 (MDC PRE), DRG 013 (MDC PRE), DRG 146 (MDC 03), DRG 147 (MDC 03), DRG 148 (MDC 03).

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

Clinical classification (AHRQ CCSR):NEO006 — Head and neck cancers - hypopharyngeal (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

Same CMS-HCC risk category (V28)

CMS maps these diagnoses to the same Hierarchical Condition Category (Lymphoma and Other Cancers) for risk-adjusted payment.

C10.3 — Malignant neoplasm of posterior wall of oropharynx, C10.4 — Malignant neoplasm of branchial cleft, C10.8 — Malignant neoplasm of overlapping sites of oropharynx, C10.9 — Malignant neoplasm of oropharynx, unspecified, C11.0 — Malignant neoplasm of superior wall of nasopharynx, C11.1 — Malignant neoplasm of posterior wall of nasopharynx, C11.2 — Malignant neoplasm of lateral wall of nasopharynx, C11.3 — Malignant neoplasm of anterior wall of nasopharynx, C11.8 — Malignant neoplasm of overlapping sites of nasopharynx, C11.9 — Malignant neoplasm of nasopharynx, unspecified, C13.0 — Malignant neoplasm of postcricoid region, C13.1 — Malignant neoplasm of aryepiglottic fold, hypopharyngeal aspect, C13.2 — Malignant neoplasm of posterior wall of hypopharynx, C13.8 — Malignant neoplasm of overlapping sites of hypopharynx, C13.9 — Malignant neoplasm of hypopharynx, unspecified, C14.0 — Malignant neoplasm of pharynx, unspecified, C14.2 — Malignant neoplasm of Waldeyer's ring, C14.8 — Malignant neoplasm of overlapping sites of lip, oral cavity and pharynx, C30.0 — Malignant neoplasm of nasal cavity, C30.1 — Malignant neoplasm of middle ear, +442 more

Related risk categories

These categories interact through CMS's HCC hierarchy — one can suppress the other's risk-adjustment weight when both are present on a claim.

Cancer Metastatic to Lung, Liver, Brain, and Other Organs; Acute Myeloid Leukemia Except Promyelocytic, Cancer Metastatic to Bone, Other and Unspecified Metastatic Cancer; Acute Leukemia Except Myeloid, Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers, Lung and Other Severe Cancers, Bladder, Colorectal, and Other Cancers, Prostate, Breast, and Other Cancers and Tumors

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Head and neck cancers - hypopharyngeal).

C13.0 — Malignant neoplasm of postcricoid region, C13.1 — Malignant neoplasm of aryepiglottic fold, hypopharyngeal aspect, C13.2 — Malignant neoplasm of posterior wall of hypopharynx, C13.8 — Malignant neoplasm of overlapping sites of hypopharynx, C13.9 — Malignant neoplasm of hypopharynx, unspecified

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

Iron Panel

Contextual Map

Every relationship of C12 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 C12 with these 7 related codes in Claim Check

Hierarchy

Use Additional Code

Same site

Referenced by Excludes2 notes

Referenced by Same-site neoplasm codes

Clinical classification (CCSR)

Risk adjustment (CMS-HCC)

  • HCC 21 — Lymphoma and Other Cancers [CMS-HCC]: “Lymphoma and Other Cancers — supersedes HCC 22 (Bladder, Colorectal, and Other Cancers), HCC 23 (Prostate, Breast, and Other Cancers and Tumors)”— CMS-HCC V28 · 2026

MS-DRG Grouper

MDC crossing

  • Pre-MDC[MDC crossing]: “Pre-MDC — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 175 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027
  • MDC 03 — Diseases and Disorders of the Ear, Nose, Mouth and Throat[MDC crossing]: “Diseases and Disorders of the Ear, Nose, Mouth and Throat — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 5,151 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027

Neoplasm sites

  • Neoplasm, neoplastic, fossa (of), piriform — Neoplasm, neoplastic, fossa (of), piriform — Malignant, Primary [Neoplasm table]: “Neoplasm, neoplastic, fossa (of), piriform (Malignant, Primary)”— CMS Table of Neoplasms · icd10cm-fy2027
  • Neoplasm, neoplastic, fossa (of), pyriform — Neoplasm, neoplastic, fossa (of), pyriform — Malignant, Primary [Neoplasm table]: “Neoplasm, neoplastic, fossa (of), pyriform (Malignant, Primary)”— CMS Table of Neoplasms · icd10cm-fy2027
  • Neoplasm, neoplastic, hypopharynx, hypopharyngeal NEC, pyriform fossa (sinus) — Neoplasm, neoplastic, hypopharynx, hypopharyngeal NEC, pyriform fossa (sinus) — Malignant, Primary [Neoplasm table]: “Neoplasm, neoplastic, hypopharynx, hypopharyngeal NEC, pyriform fossa (sinus) (Malignant, Primary)”— CMS Table of Neoplasms · icd10cm-fy2027
  • Neoplasm, neoplastic, piriform fossa or sinus — Neoplasm, neoplastic, piriform fossa or sinus — Malignant, Primary [Neoplasm table]: “Neoplasm, neoplastic, piriform fossa or sinus (Malignant, Primary)”— CMS Table of Neoplasms · icd10cm-fy2027
  • Neoplasm, neoplastic, pyriform fossa or sinus — Neoplasm, neoplastic, pyriform fossa or sinus — Malignant, Primary [Neoplasm table]: “Neoplasm, neoplastic, pyriform fossa or sinus (Malignant, Primary)”— CMS Table of Neoplasms · icd10cm-fy2027
  • Neoplasm, neoplastic, sinus (accessory), pyriform — Neoplasm, neoplastic, sinus (accessory), pyriform — Malignant, Primary [Neoplasm table]: “Neoplasm, neoplastic, sinus (accessory), pyriform (Malignant, Primary)”— CMS Table of Neoplasms · icd10cm-fy2027

Change history

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

Deep reference

Published questions and FAQ, every source behind this page with its release and checksum, the date-of-service check and the complete change history.

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 FY2027 tabular list, index and tables, effective October 1, 2026 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v44.0 (October 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 — v44 Release, file and checksum · Publisher’s page
Risk adjustment Official source data
2026 Mid-Year Final ICD-10 Mappings + Model Software (cms.gov/files/zip/2026-midyear-final-icd-10-mappings.zip, 2026-midyear-final-model-software.zip) — CMS-HCC V28, PY2026 mid-year final release 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.

Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 20, 2026 · All releases and sources

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

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "C12 — Malignant neoplasm of pyriform sinus." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/c12-malignant-neoplasm-of-pyriform-sinus

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Malignant neoplasm of pyriform sinus

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