2026 ICD-10-CM Diagnosis Code M36.8Systemic disorders of connective tissue in other diseases classified elsewhere
ICD-10-CM Codes›M00–M99›M30-M36›M36
- Billable — Valid for Submission
- Not Chronic
M36.8 is a billable ICD-10-CM diagnosis code for systemic disorders of connective tissue in other diseases classified elsewhere. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 545 through 547. The code is a manifestation code that cannot be reported as the principal diagnosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Systemic lupus erythematosus and connective tissue disorders.
M36.8 no longer risk-adjusts for Medicare Advantage: it mapped to HCC 40 under the retired CMS-HCC V24 model through payment year 2025 but maps to no category in the live V28 model. It still risk-adjusts in the PACE (CMS-HCC V22) category 40, ESRD (V21) category 40, ESRD (V24) category 40, and RxHCC Part D (V08) category 84 for payment year 2026.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for M36.8.
Medicare Risk Adjustment (HCC)Billing
M36.8 no longer risk-adjusts for Medicare Advantage: it maps to no payment category in the live CMS-HCC V28 model, although it still risk-adjusts in the other CMS models shown below.
Source: CMS Payment Year 2026 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Code First
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Connective Tissue Disorders
Your connective tissue supports many different parts of your body, such as your skin, eyes, and heart. It is like a "cellular glue" that gives your body parts their shape and helps keep them strong. It also helps some of your tissues do their work. It is made of many kinds of proteins. Cartilage and fat are types of connective tissue.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert M36.8 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About M36.8Overview
Is M36.8 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report systemic disorders of connective tissue in other diseases classified elsewhere on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does M36.8 group to?
On inpatient claims, systemic disorders of connective tissue in other diseases classified elsewhere maps to MS-DRG 545, 546, 547, with relative weights from 0.8362 to 2.4817 depending on complications. Higher weights mean higher Medicare reimbursement.
Can M36.8 be a principal diagnosis?
No. This is a manifestation code: systemic disorders of connective tissue in other diseases classified elsewhere describes the manifestation of an underlying disease rather than the disease itself, so the underlying condition is sequenced first.
What is the ICD-9 equivalent of M36.8?
Under the General Equivalence Mappings, systemic disorders of connective tissue in other diseases classified elsewhere converts to ICD-9-CM 710.9 (diff connect tis dis NOS). The mapping is approximate, so confirm the match fits the documentation.
Does M36.8 risk-adjust for Medicare Advantage payment?
Not for Medicare Advantage. M36.8 mapped to HCC 40 in the retired CMS-HCC V24 model, which last determined payment in 2025, but it maps to no category in the live V28 model; see all codes that no longer risk-adjust. It still risk-adjusts in the PACE (CMS-HCC V22) category 40 (Rheumatoid Arthritis and Inflammatory Connective Tissue Disease), ESRD (V21) category 40 (Rheumatoid Arthritis and Inflammatory Connective Tissue Disease), ESRD (V24) category 40 (Rheumatoid Arthritis and Inflammatory Connective Tissue Disease), and RxHCC Part D (V08) category 84 (Systemic Lupus Erythematosus and Other Systemic Connective Tissue Disorders).
