2025 ICD-10-CM Range M00-M99Diseases of the musculoskeletal system and connective tissueNoteUse an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal conditionType 2 Excludesarthropathic psoriasis (L40.5-)certain conditions originating in the perinatal period (P04-P96)certain infectious and parasitic diseases (A00-B99)compartment syndrome (traumatic) (T79.A-)complications of pregnancy, childbirth and the puerperium (O00-O9A)congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)endocrine, nutritional and metabolic diseases (E00-E88)injury, poisoning and certain other consequences of external causes (S00-T88)neoplasms (C00-D49)symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94) Diseases of the musculoskeletal system and connective tissue ICD-10-CM Diagnosis Code M65Synovitis and tenosynovitis2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 Non-Billable/Non-Specific Code Type 1 Excludeschronic crepitant synovitis of hand and wrist (M70.0-)current injury - see injury of ligament or tendon by body regionsoft tissue disorders related to use, overuse and pressure (M70.-) Synovitis and tenosynovitis, M65.4 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. The 2025 edition of ICD-10-CM M65.4 became effective on October 1, 2024. This is the American ICD-10-CM version of M65.4 - other international versions of ICD-10 M65.4 may differ., M65.4 is a valid billable ICD-10 diagnosis code for Radial styloid tenosynovitis [de Quervain]. It is found in the 2025 version of the ICD-10 Clinical Modification (CM) and can be used in all HIPAA-covered transactions from Oct 01, 2024 - Sep 30, 2025..