M31.1 ICD-10-CM Code: Thrombotic microangiopathy
M31.1 is not a CMS-HCC payment code. MEAT criteria · RAF Calculator · free HCC coding tools
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FY 2026 Apr update / Diseases of the musculoskeletal system and connective tissue (M00-M99) / Systemic connective tissue disorders (M30-M36)
M31.1
Header CodeICD-10-CMOfficial ICD-10-CMCodebook guidanceThrombotic microangiopathy
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
N/A—
Not mapped
ACA/HHS
N/A—
Not mapped
ESRD/PACE
N/A—
Not mapped
RXHCC
N/A—
Not mapped
Code Book Path
Inclusion Terms
OfficialNo inclusion terms are included in this display for M31.1. Check the code and parent instructions in the Code Book.
Excludes 2
Official- arthropathic psoriasis (L40.5-)Inherited from M00-M99
- certain conditions originating in the perinatal period (P04-P96)Inherited from M00-M99
- certain infectious and parasitic diseases (A00-B99)Inherited from M00-M99
- compartment syndrome (traumatic) (T79.A-)Inherited from M00-M99
- complications of pregnancy, childbirth and the puerperium (O00-O9A)Inherited from M00-M99
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)Inherited from M00-M99
- endocrine, nutritional and metabolic diseases (E00-E88)Inherited from M00-M99
- injury, poisoning and certain other consequences of external causes (S00-T88)Inherited from M00-M99
- neoplasms (C00-D49)Inherited from M00-M99
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)Inherited from M00-M99
Related Codes
Includes
Official- autoimmune disease NOSInherited from M30-M36
- collagen (vascular) disease NOSInherited from M30-M36
- systemic autoimmune diseaseInherited from M30-M36
- systemic collagen (vascular) diseaseInherited from M30-M36
Excludes 1
Official- autoimmune disease, single organ or single cell-type -code to relevant condition categoryInherited from M30-M36
Code First
OfficialNo Code First sequencing instructions are included in this display for M31.1. Check the code and parent instructions in the Code Book.
Use Additional
OfficialNo Use Additional Code instructions are included in this display for M31.1. Check the code and parent instructions in the Code Book.
Code Also
OfficialNo Code Also instructions are included in this display for M31.1. Check the code and parent instructions in the Code Book.
Buddy Documentation Tip
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
- Code
- M31.1
- Description
- Thrombotic microangiopathy
- HCC (V28)
- No CMS-HCC V28 mapping
- RAF reference coefficient
- —
- Billable
- No
- Payment year
- 2026
Coder workflow notes
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What This Code Means
M31.1 is the ICD-10-CM diagnosis code for thrombotic microangiopathy. M31.1 sits in the ICD-10-CM chapter for diseases of the musculoskeletal system and connective tissue (m00-m99), within the section covering systemic connective tissue disorders (m30-m36).
M31.1 is a non-billable category for thrombotic microangiopathy. Move through the official child-code path until the documented detail supports a reportable code.
HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for M31.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •M31.1 is a non-billable category for thrombotic microangiopathy. Move through the official child-code path until the documented detail supports a reportable code.
- •For this DOS, capture the provider's current assessment and the care action documented for thrombotic microangiopathy. Keep the checklist tied to the note.
- •Do not swap M31.1 with M31.0. The FY2026 tabular describes M31.0 as hypersensitivity angiitis. Follow the documented detail.
- •Ask Buddy to show the official notes for M31.1 or compare its code path with M31.0.