ICD-10 M31.11
Billable / Specific HCC v28: 186 MCCHematopoietic stem cell transplantation-associated thrombotic microangiopathy [HSCT-TMA]
About ICD-10-CM M31.11
ICD-10-CM code M31.11 represents Hematopoietic stem cell transplantation-associated thrombotic microangiopathy [HSCT-TMA]. This is a billable/specific code in the Musculoskeletal and Connective Tissue chapter (block M31). The 2026 edition of ICD-10-CM M31.11 became effective on October 1, 2025.
Coding Tips for M31.11
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
M31.11 is a CMS-HCC v28 risk-adjustment code (category 186). To count for the patient Risk Adjustment Factor (RAF), document the diagnosis with MEAT language each calendar year: Monitored, Evaluated, Assessed, Treated. A diagnosis on the problem list alone does not satisfy CMS RADV audit standards. Include the diagnosis in the assessment with current status and current treatment plan.
M31.11 is designated MCC for MS-DRG grouping. On inpatient claims, this code can shift the DRG to the with-MCC variant when documented as a present-on-admission secondary diagnosis. Hospital CDI programs flag MCC opportunities during chart review. Failure to capture this code may leave 30 to 80 percent of the inpatient stay revenue unrealized.
Inclusion Terms / Approximate Synonyms
Clinical terms and conditions classified under M31.11. Per CMS ICD-10-CM Tabular 2026.
- Transplant-associated thrombotic microangiopathy [TA-TMA]
Use Additional Code
When coding M31.11, also report these additional codes when applicable.
- code to identify specific organ dysfunction, such as:
- acute kidney failure (N17.-)
- acute respiratory distress syndrome (J80)
- capillary leak syndrome (I78.8)
- diffuse alveolar hemorrhage (R04.89)
- encephalopathy (metabolic) (septic) (G93.41)
- fluid overload, unspecified (E87.70)
- graft versus host disease (D89.81-)
- hemolytic uremic syndrome (D59.3-)
- hepatic failure (K72.-)
- hepatic veno-occlusive disease (K76.5)
- idiopathic interstitial pneumonia (J84.11-)
- sinusoidal obstruction syndrome (K76.5)
Coding Notes
Code First
- if applicable:
- complications of bone marrow transplant (T86.0-)
- complications of stem cell transplant (T86.5)
Medicare Advantage HCC Impact
Capture this diagnosis annually for accurate risk adjustment. Missed HCC captures are the #1 revenue leak in Medicare Advantage risk programs.
Inpatient DRG Impact, MCC
codes Hematopoietic stem cell transplantation-associated thrombotic microangiopathy [HSCT-TMA]. As a Major Complication/Comorbidity (MCC), this can shift the DRG assignment to a higher-weighted category, substantial reimbursement impact.
Medicare LCD Coverage for M31.11
Local Coverage Determinations (LCDs) from CMS MACs that list M31.11 as a covered diagnosis.
Showing top 10 of 82 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing M31.11.
5 Medicare
1 Aetna
CPT Codes Commonly Billed with M31.11
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
We don't have CPT pairings indexed for this specific code yet. Use the CPT search above to find common procedures, or check your payer's published medical policy for code-specific guidance.
Codes Adjacent To M31.11
Other codes in section M30-M36 (Systemic connective tissue disorders).
ICD-10 M31.11, Billing FAQ
Is ICD-10 code M31.11 billable? +
Yes, M31.11 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
What other names or terms map to M31.11? +
ICD-10 M31.11 includes: Transplant-associated thrombotic microangiopathy [TA-TMA].
Does M31.11 affect Medicare Advantage HCC risk adjustment? +
Yes. M31.11 maps to CMS-HCC v28 category 186. Capture this diagnosis annually for accurate Medicare Advantage risk score.
Is M31.11 a CC or MCC for inpatient DRG? +
Yes, this code is designated as MCC. Documenting as a secondary diagnosis on inpatient claims can shift the DRG to a higher-weighted category.
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on June 1, 2026.
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