2026 ICD-10-CM Diagnosis Code R76.81Abnormal rheumatoid factor and anti-citrullinated protein antibody without rheumatoid arthritis
R76.81 is a billable ICD-10-CM diagnosis code for abnormal rheumatoid factor and anti-citrullinated protein antibody without rheumatoid arthritis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 814 through 816. As a symptom code, it should not be used as a principal diagnosis once a related definitive diagnosis has been established.
Code Identity
Code Classification
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Abnormal anti-CCP
- Abnormal anti-cyclic citrullinated protein antibody and rheumatoid factor
Type 1 Excludes
- rheumatoid arthritis with rheumatoid factor M05
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.
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- Abnormal, abnormality, abnormalities - See Also: Anomaly;
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Abnormal, abnormality, abnormalities
- anti-cyclic citrullinated protein antibody and rheumatoid factor
- Abnormal, abnormality, abnormalities
- anti-CCP (cyclic citrullinated protein)
- Abnormal, abnormality, abnormalities
- rheumatoid factor and anti-citrullinated protein antibody
- without rheumatoid arthritis
Code History & ChangesHistory
New Code R76.81 was added to the ICD-10-CM code set for FY 2026, effective October 1, 2025.
Replacement R76.81 replaces the following previously assigned code(s):
- R76.8 - Other specified abnormal immunological findings in serum
Questions About R76.81Overview
Is R76.81 (Other specified abnormal immunological findings in serum) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report abnormal rheumatoid factor and anti-citrullinated protein antibody without rheumatoid arthritis on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does R76.81 group to?
When abnormal rheumatoid factor and anti-citrullinated protein antibody without rheumatoid arthritis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 814, 815, 816, with relative weights from 0.6320 to 2.1267 depending on complications. Higher weights mean higher Medicare reimbursement.
Can R76.81 be a principal diagnosis?
Use it with care. This is a symptom code, so once a definitive diagnosis explaining the abnormal rheumatoid factor and anti-citrullinated protein antibody without rheumatoid arthritis is established, that condition takes the principal position instead.
