The International Classification of Diseases, Tenth Revision (ICD-10) is the global numerical system for coding diseases, procedures and medical symptoms and conditions. Updated annually, the newest ICD-10 code set went into effect on Oct. 1 and includes about 395 new diagnosis codes, 25 deleted codes, 22 revised codes, 131 new header codes and four revised headers.
The following ICD-10 code updates for rheumatology practices provide specificity for conditions affecting bones, joints or muscles in Chapter 13 – Diseases of the Musculoskeletal System and Connective Tissue, which expands on synovitis and tenosynovitis by adding information for specific locations.
| M65.971 | Unspecified synovitis and tenosynovitis, right ankle and foot |
| M65.972 | Unspecified synovitis and tenosynovitis, left ankle and foot |
| M65.979 | Unspecified synovitis and tenosynovitis, unspecified ankle and foot |
| M65.98 | Unspecified synovitis and tenosynovitis, other site |
| M65.99 | Unspecified synovitis and tenosynovitis, multiple sites |
The ICD-10 Official Guidelines for Coding and Reporting for 2025 are minimal, but include updates necessary to maintain consistency in how diagnostic codes are referenced in the manual. The ICD-10 updates are meant to improve the accuracy of diagnostic coding for numerous conditions and to delete and alter codes whose use has changed. Additionally, the updates ensure consistency in referencing the coding guidelines, address social barriers, align with new rulings regarding payment, and capture acuity of patients and the care provided.
To prepare for the new codes and remain compliant with diagnostic coding standards, rheumatology practices should:
- Make sure all coders and providers understand ICD-10 codes for rheumatic and musculoskeletal diseases and how to use them;
- Be attentive of the anatomy and structures involved in patient health records; and
- Utilize a documentation system to verify codes are applied accurately.
ICD-10 Coordination & Maintenance
The World Health Organization owns and publishes ICD-10 but has authorized the Centers for Disease Control & Prevention (CDC) National Center for Health Statistics (NCHS) to develop annual modifications. The formal process is performed twice a year through the ICD-10 Coordination and Maintenance Committee, which comprises representatives from the Centers for Medicare & Medicaid Services (CMS) and NCHS.
The ACR attends each public meeting. At the September 2024 meeting, ACR representatives proposed a new diagnosis code to describe abnormal rheumatoid factor and anti-citrullinated protein antibody without rheumatoid arthritis. As the next step in the process, the CMS will leave the proposal open for 60 days and solicit public comments regarding any clinical questions or coding options for the code proposal. The final decisions on code revisions are made through a clearance process within the Department of Health & Human Services (HHS). The ACR will release additional information once it receives the final recommendation from NCHS.
