C94.40 Acute panmyelosis with myelofibrosis not having achieved remission

ICD-10-CM C94.40: Acute panmyelosis with myelofibrosis not having achieved remission

ICD-10-CM code C94.40 identifies acute panmyelosis with myelofibrosis not having achieved remission, a rare acute myeloid leukemia subtype with simultaneous bone marrow cell proliferation and fibrosis. The code is billable and maps to specific CMS-HCC risk adjustment categories. Medicare documents reference this code alongside remission status codes within genomic sequencing and myeloid malignancy billing articles. 2 3 4 5 6

Plain-language overview

Acute panmyelosis with myelofibrosis is a rare subtype of acute myeloid leukemia characterized by simultaneous abnormal proliferation of all bone marrow cell lineages, including erythroid, granulocytic, and megakaryocytic cells, with concurrent fibrosis. 2 6

What this code represents

The ICD-10-CM diagnosis code C94.40 specifically represents acute panmyelosis with myelofibrosis not having achieved remission, distinguishing it from other clinical statuses of the same condition. 3 6

Coding details

C94.40 is a billable ICD-10-CM diagnosis code that maps to Cancer Metastatic to Lung, Liver, Brain, and Other Organs and Acute Myeloid Leukemia Except Promyelocytic under the CMS-HCC V28 risk adjustment model with a community non-dual aged base RAF weight of 4.209. 6

Under the older CMS-HCC V24 model, C94.40 maps to Metastatic Cancer and Acute Leukemia with a community non-dual aged base RAF weight of 2.659, while the current V28 model assigns it a weight of 4.209. 6

Documentation considerations

The ICD-10-CM system provides distinct codes for acute panmyelosis with myelofibrosis based on remission status, listing C94.40 for not having achieved remission, C94.41 for in remission, and C94.42 for another status. 4 5

Coverage and utilization context

The Centers for Medicare and Medicaid Services references C94.40 within billing and coding articles for genomic sequence analysis panels in hematolymphoid diseases and next-generation sequencing lab-developed tests for myeloid malignancies. 4 5

What the sources add

Clinical literature classifies acute panmyelosis with myelofibrosis as a rare acute myeloid leukemia subtype that can display CD33 positive cellular markers, whereas coding references focus on its billable status and risk adjustment mappings. 2 6

The National Cancer Institute terminology source confirms the exact ICD-10-CM label for C94.40 as acute panmyelosis with myelofibrosis not having achieved remission, while a separate coding reference adds the physiological definition involving bone marrow cell lineages and fibrosis. 3 6

Sources

1. Bookshelf — ncbi.nlm.nih.gov; accessed 2026-07-26.
2. Management of challenging myelofibrosis after JAK inhibitor failure and/or progression — pmc.ncbi.nlm.nih.gov; accessed 2026-07-26.
3. EVS Explore — evsexplore.semantics.cancer.gov; accessed 2026-07-26.
4. Article - Billing and Coding: Genomic Sequence Analysis Panels in the Treatment of Hematolymphoid Diseases (A56793) — cms.gov; accessed 2026-07-26.
5. Article - Billing and Coding: MolDX: Next-Generation Sequencing Lab-Developed Tests for Myeloid Malignancies and Suspected Myeloid Malignancies (A57892) — cms.gov; accessed 2026-07-26.
6. 2026 ICD-10-CM C94.40: Acute panmyelosis | HCC 17 — hccbuddy.com; accessed 2026-07-26.