D56.0 Alpha Thalassemia Does Not Map in V28. D56.1 / D56.2 / D56.5 Are HCC 108.

If you searched alpha thalassemia, D56.0, or nearby thalassemia leaves next to V28, you are looking at a D56 cluster where only three billable leaves map under CMS-HCC V28 for payment year 2026, and several nearby leaves do not.

D56.0 (Alpha thalassemia) is billable. It does not map in CMS-HCC V28. The PY2026 V28 CSV has no row for `D560`. Do not invent a payment map for alpha thalassemia, hemoglobin H disease language parked on D56.0, or Constant Spring phrasing that still lands on a no-map leaf.

Three nearby D56 leaves do map. The PY2026 CSV rows are `D561,108.0,,,`, `D562,108.0,,,`, and `D565,108.0,,,`:

• D56.1 Beta thalassemia -> HCC 108
• D56.2 Delta-beta thalassemia -> HCC 108
• D56.5 Hemoglobin E-beta thalassemia -> HCC 108

The live HCC 108 hub title is Sickle Cell Disorders, Except Sickle Cell Anemia (Hb-SS), with a source-labeled community non-dual aged reference coefficient of 0.146 and 39 ICD rows. That hub lists D56.1, D56.2, and D56.5. That is a category reference, not a member RAF total.

Other D56 leaves are also billable when documented, but they do not map in V28 (no CSV row):

• D56.3 Thalassemia minor
• D56.4 Hereditary persistence of fetal hemoglobin [HPFH]
• D56.8 Other thalassemias
• D56.9 Thalassemia, unspecified

Billable is not the same as risk-adjusted. Do not substitute D56.1, D56.2, or D56.5 to force HCC 108 when the chart only supports alpha thalassemia, thalassemia minor, HPFH, other thalassemia, or unspecified thalassemia.

As of October 2, 2026, the public ICD leaf cards default to the FY2027 ICD-10-CM edition and show CMS-HCC V28 source verification pending site-wide. Payment maps in this desk are verified from the PY2026 V28 CSV and the live HCC 108 hub listing. Re-check the live leaf card when FY2027 mapping verification returns.

Related hierarchy context (not a D56 substitute path): HCC 107 Sickle Cell Anemia (Hb-SS) and Thalassemia Beta Zero has CNA ref 0.457 and 14 ICD rows. The HCC 108 hub notes that HCC 108 is superseded by HCC 107 when a more severe category in the same disease group is also present. None of the D56 leaves in this desk map to HCC 107 in the PY2026 CSV.

This page is the coder-desk walk for the D56.0 / thalassemia map trap under CMS-HCC V28 for payment year 2026.

Desk table: verified maps (2026-10-02)

HCC 108 coeff ref 0.146 is the live hub community non-dual aged reference. Not a member total. Segment coefficients vary.

What D56.0 means on the claim

D56.0 is the alpha thalassemia leaf. Use it when the chart supports alpha thalassemia. It can still be the correct ICD-10-CM code when documented. It does not create a V28 HCC by itself.

Do not substitute D56.1, D56.2, or D56.5 to force HCC 108. Those leaves are for beta thalassemia, delta-beta thalassemia, and hemoglobin E-beta thalassemia when the chart supports those conditions.

Do not treat D56.3 (thalassemia minor), D56.4 (HPFH), D56.8 (other thalassemias), or D56.9 (unspecified) as risk-adjusted because nearby D56.1 maps. Map is leaf-specific.

Coding paths (documentation-driven)

Pick the path from what the chart actually supports. Do not invent beta thalassemia, delta-beta thalassemia, or hemoglobin E-beta thalassemia for RAF.

1. Chart supports alpha thalassemia -> D56.0 -> billable, no V28 map.

2. Chart supports beta thalassemia -> D56.1 -> V28 HCC 108.

3. Chart supports delta-beta thalassemia -> D56.2 -> V28 HCC 108.

4. Chart supports hemoglobin E-beta thalassemia -> D56.5 -> V28 HCC 108.

5. Chart supports thalassemia minor -> D56.3 -> billable, no V28 map.

6. Chart supports hereditary persistence of fetal hemoglobin -> D56.4 -> billable, no V28 map.

7. Chart supports other thalassemias without a more specific mapped leaf -> D56.8 -> billable, no V28 map.

8. Chart supports thalassemia, unspecified -> D56.9 -> billable, no V28 map.

9. Do not treat billable as risk-adjusted without checking the CSV and the live HCC hub.

10. Do not invent member RAF totals from the 0.146 reference.

11. If a sickle-cell anemia (Hb-SS) / thalassemia beta zero path is also present, follow the chart and check HCC 107 hierarchy rules. Do not invent a D56 leaf into HCC 107.

MEAT for mapped HCC 108

A mapped D56.1, D56.2, or D56.5 still needs monitoring, evaluation, assessment, or treatment in the eligible encounter year. A problem-list row that says "thalassemia" from a prior year does not carry the HCC forward by itself.

For mapped leaves in this desk, the note should support:

• M Monitor: hemoglobin pattern, transfusion needs when documented, iron overload surveillance when relevant, symptoms, safety
• E Evaluate: electrophoresis or genotype results when used, phenotype vs trait language when documented, complications when present
• A Assess: explicit beta thalassemia, delta-beta thalassemia, or hemoglobin E-beta thalassemia (not only "thalassemia" when a more specific mapped leaf is supported, and not alpha thalassemia labeled as beta)
• T Treat: hematology plan, transfusion plan, chelation when documented, medication or specialty follow-up when relevant

MEAT is a review mnemonic, not a universal CMS coding rule. Follow the applicable coding, encounter, program, and payer requirements. See MEAT and problem lists.

Audit and query traps

1. Coding D56.0 as if it maps to HCC 108 in V28. It does not. No CSV row.

2. Treating billable D56.3 / D56.4 / D56.8 / D56.9 as risk-adjusted because D56.1 maps. Map is leaf-specific.

3. Forcing D56.1 when the chart only supports alpha thalassemia, trait/minor language, HPFH, or unspecified thalassemia.

4. Parking hemoglobin H / Constant Spring documentation on a no-map leaf and still expecting HCC 108.

5. Using the 0.146 CNA reference as a member RAF total.

6. Inventing Coding Clinic quotes, competitor CTAs, or PHI examples.

7. Inventing a D56 map into HCC 107. In the PY2026 CSV, the D56 leaves in this desk that map go to HCC 108 only.

8. Coding a historical "thalassemia" label with no current MEAT in the eligible year for a mapped leaf.

9. Ignoring hierarchy when a true HCC 107 sickle-cell anemia (Hb-SS) / thalassemia beta zero category is also supported. Follow the chart and the live hubs.

Related desks and tools

• Live cards: D56.0, D56.1, D56.2, D56.3, D56.4, D56.5, D56.8, D56.9
• Hubs: HCC 108, HCC 107
• Lookup: ICD-10 to HCC, Encoder
• Evidence habits: MEAT, problem lists
• Nearby map/trap desks: N18.9 CKD, D68.311 acquired hemophilia, E24.0 pituitary Cushing

Current as of October 2, 2026. Always confirm the PY2026 V28 CSV and the live HCC hub before you lock a map claim. Re-check the leaf card when FY2027 V28 verification is no longer pending.