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C80.0 ICD-10-CM Code: Disseminated malignant neoplasm, unspecified

Compare with another codeCheck this code on a claim

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

Coding at a Glance

Tabular directives
3 inclusion terms · 2 Excludes1
Risk adjustment
CMS-HCC V28: 1 category · CMS-HCC V22 category 8 · RxHCC V08 category 20

Billable · FY2027A valid, specific ICD-10-CM code, reportable for dates of service in FY2027.

What you need to know

Source: CMS/NCHS Official ICD-10-CM tabular notes, quoted. From the CMS/NCHS tabular list for the release in force. A note the category or block publishes applies to this code too; the Instructions section marks which is which.

Excludes1Never report with this code
  • malignant carcinoid tumor of unspecified site (C7A.00)
  • malignant neoplasm of specified multiple sites- code to each site
IncludesWhat this code covers
  • Carcinomatosis NOS
  • Generalized cancer, unspecified site (primary) (secondary)
  • Generalized malignancy, unspecified site (primary) (secondary)

Most relevant related codes MedCoder-derived

Read off the official notes above and this code’s own position in the tabular list. Which to report is a documentation question; Compare shows the two side by side.

CompareCheck ClaimView Related Codes

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 826 — MYELOPROLIFERATIVE DISORDERS OR POORLY DIFFERENTIATED NEOPLASMS WITH MAJOR O.R. PROCEDURES WITH MCC (MDC 17)
  • MS-DRG 827 — MYELOPROLIFERATIVE DISORDERS OR POORLY DIFFERENTIATED NEOPLASMS WITH MAJOR O.R. PROCEDURES WITH CC (MDC 17)
  • MS-DRG 828 — MYELOPROLIFERATIVE DISORDERS OR POORLY DIFFERENTIATED NEOPLASMS WITH MAJOR O.R. PROCEDURES WITHOUT CC/MCC (MDC 17)
  • MS-DRG 829 — MYELOPROLIFERATIVE DISORDERS OR POORLY DIFFERENTIATED NEOPLASMS WITH OTHER PROCEDURES WITH CC/MCC (MDC 17)
  • MS-DRG 830 — MYELOPROLIFERATIVE DISORDERS OR POORLY DIFFERENTIATED NEOPLASMS WITH OTHER PROCEDURES WITHOUT CC/MCC (MDC 17)
  • MS-DRG 843 — OTHER MYELOPROLIFERATIVE DISORDERS OR POORLY DIFFERENTIATED NEOPLASTIC DIAGNOSES WITH MCC (MDC 17)
  • MS-DRG 844 — OTHER MYELOPROLIFERATIVE DISORDERS OR POORLY DIFFERENTIATED NEOPLASTIC DIAGNOSES WITH CC (MDC 17)
  • MS-DRG 845 — OTHER MYELOPROLIFERATIVE DISORDERS OR POORLY DIFFERENTIATED NEOPLASTIC DIAGNOSES WITHOUT CC/MCC (MDC 17)

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 18 — Cancer Metastatic to Bone, Other and Unspecified Metastatic Cancer; Acute Leukemia Except Myeloid (supersedes HCC 19, HCC 20, HCC 21, HCC 22, HCC 23)

Other models: CMS-HCC V22 HCC 8 · RxHCC V08 HCC 20

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 C80.0 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

Notes without a marker are published on C80.0 itself; “inherited from” names the category or block whose note applies here.

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Carcinomatosis NOS
  • Generalized cancer, unspecified site (primary) (secondary)
  • Generalized malignancy, unspecified site (primary) (secondary)

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Source: inherited from C80

Coder workflow for C80.0

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

Before you code C80.0

  1. Unspecified does not mean incorrect. When the record gives no greater specificity, C80.0 may be the appropriate code. Check the record for detail that supports a more specific sibling. An unspecified code is for records that do not provide the detail a more specific code needs; a query, not an assumption, is the route to specificity (Guidelines I.A.9.b, I.B.18).

    ReviewC80.2

    See the relationships section · Guide: Other vs unspecified (NEC vs NOS) →

  2. 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 →

  3. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with C80.0. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

    See the official tabular notes

Choose the right path

  1. Does the record document the detail a more specific sibling code needs?
    Yes → Review the specific siblings in this subcategory.
    No → Continue — C80.0 is appropriate when the documentation goes no further.

    ReviewC80.2

  2. Does the documentation support a condition named in C80.0’s Excludes1 note?
    Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
    No → Continue.

    ReviewC7A.00

Consider C80.0. Then confirm the code is valid for the date of service in the Verify section.

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.
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).
Any detail beyond this code’s title
What the record states that a more specific sibling code would capture — or its absence, which itself supports the unspecified code.

Official instructions as workflow

  • Excludes1 — check before selecting C80.0(2 notes)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with C80.0: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareC7A.00

    See the official tabular notes · Guidelines I.A.12.a

Coding decision scenarios

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

Documentation: The provider documents the condition in the terms of this code’s title and records no further detail.

Coding question: Is a more specific sibling code supportable?

Path: Review the specific siblings in this subcategory and what each requires the record to state.

Reason: A more specific code needs documentation of the distinguishing element; without it the unspecified code is appropriate, and a provider query is the route to specificity (Guidelines I.A.9.b, I.B.18).

ReviewC80.2

Documentation: Both the condition C80.0 describes and a condition named in its Excludes1 note are documented for the same encounter.

Coding question: Can both codes be reported?

Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.

Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).

ReviewC7A.00

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.

Don’t confuse C80.0 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of C80.0 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

  • C7A.00— Excludes1 conflict (Excludes1 — generally not reported together)

    Not coded here — the tabular list excludes this pair for the same encounter.

    Not reported together with this code, except where the two conditions are documented as unrelated.

    What moves you there: Documentation of malignant carcinoid tumor of unspecified site moves the case to C7A.00; the two are not reported together unless documented as unrelated.

    Full comparison: C80.0 vs C7A.00 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Coding context

Guidelines, coding notes, decision aids, relationships (with MS-DRG and CCSR classification), hierarchy, HCC, coverage and the context map: what a coder reaches for after the core. Each section names whether it is official source data, a MedCoder-derived relationship or MedCoder editorial.

Code Overview

Disseminated malignant neoplasm, unspecified is a billable ICD-10-CM diagnosis code (C80.0).

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

Official Coding 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 2: Neoplasms (C00-D49 )

j. Disseminated malignant neoplasm, unspecified Code C80.0, Disseminated malignant neoplasm, unspecified, is for use only in those cases where the patient has advanced metastatic disease and no known primary or secondary sites are specified. It should not be used in place of assigning codes for the primary site and all known secondary sites.

Verify Before Coding

  • CC as a secondary diagnosis (FY2027). Can raise the stay's MS-DRG severity tier.

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-derived relationships — computed from published CMS and AHRQ datasets

Other codes that name C80.0 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 Excludes1 note: C79.9 — Secondary malignant neoplasm of unspecified site.

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 MS-DRG: CC — Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 19 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 8 MS-DRGs: DRG 826 (MDC 17), DRG 827 (MDC 17), DRG 828 (MDC 17), DRG 829 (MDC 17), DRG 830 (MDC 17), DRG 843 (MDC 17), DRG 844 (MDC 17), DRG 845 (MDC 17).

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

Clinical classification (AHRQ CCSR):NEO071 — Malignant neoplasm, unspecified (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 clinical process (MS-DRG)

Acts as CC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.

C45.7 — Mesothelioma of other sites, C45.9 — Mesothelioma, unspecified, C76.8 — Malignant neoplasm of other specified ill-defined sites, C79.83 — Secondary malignant neoplasm of oral cavity, C79.89 — Secondary malignant neoplasm of other specified sites, C79.9 — Secondary malignant neoplasm of unspecified site, C7A.00 — Malignant carcinoid tumor of unspecified site, C7A.098 — Malignant carcinoid tumors of other sites, C7A.1 — Malignant poorly differentiated neuroendocrine tumors, C7A.8 — Other malignant neuroendocrine tumors, C7B.00 — Secondary carcinoid tumors, unspecified site, C7B.09 — Secondary carcinoid tumors of other sites, C7B.1 — Secondary Merkel cell carcinoma, C7B.8 — Other secondary neuroendocrine tumors, C80.1 — Malignant (primary) neoplasm, unspecified, D49.81 — Neoplasm of unspecified behavior of retina and choroid, D49.89 — Neoplasm of unspecified behavior of other specified sites, D49.9 — Neoplasm of unspecified behavior of unspecified site

Same CMS-HCC risk category (V28)

CMS maps these diagnoses to the same Hierarchical Condition Category (Cancer Metastatic to Bone, Other and Unspecified Metastatic Cancer; Acute Leukemia Except Myeloid) for risk-adjusted payment.

C79.10 — Secondary malignant neoplasm of unspecified urinary organs, C79.11 — Secondary malignant neoplasm of bladder, C79.19 — Secondary malignant neoplasm of other urinary organs, C79.2 — Secondary malignant neoplasm of skin, C79.51 — Secondary malignant neoplasm of bone, C79.52 — Secondary malignant neoplasm of bone marrow, C79.60 — Secondary malignant neoplasm of unspecified ovary, C79.61 — Secondary malignant neoplasm of right ovary, C79.62 — Secondary malignant neoplasm of left ovary, C79.63 — Secondary malignant neoplasm of bilateral ovaries, C79.81 — Secondary malignant neoplasm of breast, C79.82 — Secondary malignant neoplasm of genital organs, C79.89 — Secondary malignant neoplasm of other specified sites, C79.9 — Secondary malignant neoplasm of unspecified site, C91.00 — Acute lymphoblastic leukemia not having achieved remission, C91.01 — Acute lymphoblastic leukemia, in remission, C91.02 — Acute lymphoblastic leukemia, in relapse, C95.00 — Acute leukemia of unspecified cell type not having achieved remission, C95.01 — Acute leukemia of unspecified cell type, in remission, C95.02 — Acute leukemia of unspecified cell type, in relapse, +5 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, Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers, Lung and Other Severe Cancers, Lymphoma and Other 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 (Malignant neoplasm, unspecified).

C80.1 — Malignant (primary) neoplasm, unspecified, C80.2 — Malignant neoplasm associated with transplanted organ, D09.9 — Carcinoma in situ, unspecified, Z19.1 — Hormone sensitive malignancy status, Z19.2 — Hormone resistant malignancy status

Same Index main term, other category

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

C53.9 — Malignant neoplasm of cervix uteri, unspecified (solid, microinvasive, unspecified site), C56 — Malignant neoplasm of ovary (granulosa cell), C56.9 — Malignant neoplasm of unspecified ovary (papillocystic, unspecified site), C58 — Malignant neoplasm of placenta (chorionic, unspecified site, female), C61 — Malignant neoplasm of prostate (endometrioid, unspecified site, male), C62.90 — Malignant neoplasm of unspecified testis, unspecified whether descended or undescended (Sertoli cell, unspecified site), C64 — Malignant neoplasm of kidney, except renal pelvis (renal cell), C73 — Malignant neoplasm of thyroid gland (Hurthle cell), C74.0 — Malignant neoplasm of cortex of adrenal gland (adrenal cortical), C75.0 — Malignant neoplasm of parathyroid gland (water-clear cell), C75.1 — Malignant neoplasm of pituitary gland (basophil, unspecified site), C78.6 — Secondary malignant neoplasm of retroperitoneum and peritoneum (peritonei), C7A.1 — Malignant poorly differentiated neuroendocrine tumors (neuroendocrine, high grade, any site), C7B.1 — Secondary Merkel cell carcinoma (secondary, Merkel cell), D05.0 — Lobular carcinoma in situ of breast (noninfiltrating, lobular, breast), D05.1 — Intraductal carcinoma in situ of breast (intraductal, breast), D06.0 — Carcinoma in situ of endocervix (cervix uteri, in situ, endocervix), D06.1 — Carcinoma in situ of exocervix (cervix uteri, in situ, exocervix), D06.7 — Carcinoma in situ of other parts of cervix (cervix uteri, in situ, specified site NEC), D06.9 — Carcinoma in situ of cervix, unspecified (cervix uteri, in situ), +33 more

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.

Fecal Occult Blood Test (FOBT), Iron Panel

Contextual Map

Every relationship of C80.0 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 C80.0 with this related code in Claim Check

Hierarchy

Referenced by Excludes1 notes

Clinical classification (CCSR)

Risk adjustment (CMS-HCC)

  • HCC 18 — Cancer Metastatic to Bone, Other and Unspecified Metastatic Cancer; Acute Leukemia Except Myeloid [CMS-HCC]: “Cancer Metastatic to Bone, Other and Unspecified Metastatic Cancer; Acute Leukemia Except Myeloid — supersedes HCC 19 (Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers), HCC 20 (Lung and Other Severe Cancers), HCC 21 (Lymphoma and Other Cancers), 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

  • MDC 17 — Myeloproliferative Diseases and Disorders, Poorly Differentiated Neoplasms[MDC crossing]: “Myeloproliferative Diseases and Disorders, Poorly Differentiated Neoplasms — 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. 4,735 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027

Neoplasm sites

  • Neoplasm, neoplastic, disease, generalized — Neoplasm, neoplastic, disease, generalized — Malignant, Primary [Neoplasm table]: “Neoplasm, neoplastic, disease, generalized (Malignant, Primary)”— CMS Table of Neoplasms · icd10cm-fy2027
  • Neoplasm, neoplastic, disseminated — Neoplasm, neoplastic, disseminated — Malignant, Primary [Neoplasm table]: “Neoplasm, neoplastic, disseminated (Malignant, Primary)”— CMS Table of Neoplasms · icd10cm-fy2027
  • Neoplasm, neoplastic, generalized — Neoplasm, neoplastic, generalized — Malignant, Primary [Neoplasm table]: “Neoplasm, neoplastic, generalized (Malignant, Primary)”— CMS Table of Neoplasms · icd10cm-fy2027

Index entries

  • Carcinoma (malignant), generalized, with unspecified primary site[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Carcinomatosis[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Carcinomatosis, unspecified site (primary) (secondary)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027

Nearest codes

Change history

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

Reference

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

Indexed Clinical Terms (3)

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.

Neoplasm Table Sites (3)

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, disease, generalized — Malignant, Primary
  • Neoplasm, neoplastic, disseminated — Malignant, Primary
  • Neoplasm, neoplastic, generalized — Malignant, Primary

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
Coding guidelines Official source data
ICD-10-CM Official Guidelines for Coding and Reporting (FY2027), quoted by section 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-derived 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 editorial 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-derived relationship · MedCoder editorial 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. "C80.0 — Disseminated malignant neoplasm, unspecified." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/c80.0-disseminated-malignant-neoplasm-unspecified

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Disseminated malignant neoplasm, unspecified

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.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to C80.0 in its code family, with their registry titles.

View all codes in the C80 family