2026 ICD-10-CM Diagnosis Code M32.12Pericarditis in systemic lupus erythematosus
ICD-10-CM Codes›M00–M99›M30-M36›SLE
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Risk Adjusts — HCC 94
- Chronic Condition
M32.12 is a billable ICD-10-CM diagnosis code for pericarditis in systemic lupus erythematosus. 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. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 17 closely related codes. Coders also document this condition as pericarditis secondary to systemic lupus erythematosus. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Pericarditis and pericardial disease and Systemic lupus erythematosus and connective tissue disorders.
For Medicare Advantage risk adjustment, M32.12 maps to CMS-HCC Category 94 (Systemic Lupus Erythematosus and Other Specified Systemic Connective Tissue Disorders) under the V28 model, adding a risk factor of about 0.268 for a community, non-dual, aged beneficiary in payment year 2026.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
M32.12 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2026.
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.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Pericarditis secondary to systemic lupus erythematosus
- Systemic lupus erythematosus with pericarditis
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Lupus pericarditis
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Lupus
Lupus is a chronic (long-lasting) type of autoimmune disease.Autoimmune diseases happen when your immune system attacks healthy cells and tissues by mistake. This attack causes inflammation. It can also damage many parts of the body, including the joints, skin, kidneys, heart, lungs, and brain.
The full article covers:
- What is lupus?
- What causes lupus?
- Who is more likely to get lupus?
- What are the symptoms of lupus?
- What other problems can lupus cause?
- How is lupus diagnosed?
- What are the treatments for lupus?
- How can I cope with lupus?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert M32.12 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About M32.12Overview
What is the ICD-10 code for pericarditis in systemic lupus erythematosus?
The ICD-10-CM code for pericarditis in systemic lupus erythematosus is M32.12 (sometimes written as M3212). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is M32.12 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report pericarditis in systemic lupus erythematosus on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does M32.12 group to?
When pericarditis in systemic lupus erythematosus is the principal diagnosis on an inpatient stay, it groups to MS-DRG 545, 546, 547, with relative weights from 0.8362 to 2.4817 depending on complications. Higher weights mean higher Medicare reimbursement.
Is M32.12 a CC or MCC?
CMS lists M32.12 as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 17 closely related codes in its exclusion list.
What is the ICD-9 equivalent of M32.12?
Under the General Equivalence Mappings, pericarditis in systemic lupus erythematosus converts to ICD-9-CM 710.0 (syst lupus erythematosus) and 420.0 (ac pericardit in oth dis). The mapping is approximate, so confirm the match fits the documentation.
What HCC is M32.12?
M32.12 (pericarditis in systemic lupus erythematosus) maps to CMS-HCC Category 94 (Systemic Lupus Erythematosus and Other Specified Systemic Connective Tissue Disorders), commonly written as HCC 94, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2026. It mapped to HCC 40 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 84.
Does M32.12 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, M32.12 adds a risk adjustment factor of about 0.268 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.196 to 0.297 depending on the payment segment). A more severe related category (HCC 93) supersedes it when both are reported. See the full factor table on the HCC 94 category page.
