D46.21

Billable

Refractory anemia with excess of blasts 1

HCC Category Mapping

V28HCC 19 — Lymphoma and Other Cancers

0.105

V24HCC 46 — Severe Hematological Disorders

0.666

ESRDHCC 46 — Severe Hematological Disorders

0.000

RxHCCHCC 19 — Lymphoma and Other Cancers

0.000

What This Code Means

A bone marrow disorder where red blood cells cannot be produced normally and there is an excess of immature blood cells at 5-9% of the bone marrow.

Coding Tips

•Requires documentation of blast percentage between 5-9%
•Distinguish from D46.22 which indicates 10-19% blasts

Clinical Significance

Refractory anemia with excess of blasts 1 (RAEB-1) is a higher-risk myelodysplastic syndrome subtype with 5-9% blasts in the bone marrow. This condition carries an intermediate risk of progressing to acute myeloid leukemia, with a median survival of approximately 18-25 months, and typically requires close hematologic surveillance and possibly disease-modifying therapy.

Documentation Requirements

✓Documentation must include bone marrow biopsy confirming blast percentage between 5-9%, along with cytogenetic analysis and International Prognostic Scoring System score.
✓Document peripheral blood counts, transfusion requirements, and any treatment with hypomethylating agents or other therapies.
✓The specific blast percentage must be explicitly stated in pathology.

Commonly Confused Codes

D46.22 (RAEB-2, 10-19% blasts) indicates a higher blast count with worse prognosis.D46.20 (excess blasts, unspecified) should not be used when the blast percentage is documented.D46.0 (refractory anemia without ring sideroblasts) has a lower blast count.C92.00 (acute myeloblastic leukemia) is used when blasts reach 20%.

Code Hierarchy

└D46Myelodysplastic syndromes └D46.2Refractory anemia with excess of blasts [RAEB]└D46.21Refractory anemia with excess of blasts 1

└D46.21Refractory anemia with excess of blasts 1