COSC study guide
COSC · Work through your exam, one topic at a time.
The Certified Orthopaedic Surgery Coder (COSC) credential is intended for coders who assign CPT and ICD-10-CM codes for musculoskeletal care, including fracture and dislocation treatment, arthroscopy, spine and joint replacement, and the modifiers and compliance rules that surround surgical coding. It is aimed at experienced orthopaedic coders, ambulatory surgery and hospital outpatient coders, billing specialists, auditors, and clinicians who need to understand coding logic rather than only terminology. The COSC study guide has 7 sections and about 2,181 words.
01Orthopaedic Anatomy, Terminology, and Operative Report Fundamentals
Long bones are described by region: epiphysis, physis (growth plate), metaphysis, and diaphysis. Fracture and manipulation codes turn on these regions, so a metaphyseal fracture is not the same code as a diaphyseal one.
348 words, about 2 min02Musculoskeletal CPT Coding: Fractures, Dislocations, and Trauma Repair
CPT organizes fracture treatment by site and method: closed without manipulation, closed with manipulation, percutaneous, and open. With manipulation requires a documented reduction, not merely cast application.
313 words, about 2 min03Arthroscopy and Minimally Invasive Joint Procedures
Arthroscopy codes are joint-specific and often compartment-specific. A diagnostic scope is included in any surgical arthroscopy of the same joint, so never report a diagnostic code with a surgical one.
290 words, about 1 min04Spine, Arthroplasty, and Major Joint Replacement Coding
Spine codes are built on approach (anterior, posterior, lateral), level or interspace, and procedure (decompression, discectomy, corpectomy, fusion, instrumentation). Count interspaces, not vertebrae: a fusion from L4 to L5 is one interspace.
298 words, about 1 min05ICD-10-CM Diagnosis Coding for Musculoskeletal Conditions and Injuries
Musculoskeletal diagnosis codes live in Chapter 13 (M00-M99) and injury codes in Chapter 19 (S00-T88). Most musculoskeletal codes require site and laterality.
305 words, about 2 min06Modifiers, Surgical Package, and E/M Services in Orthopaedic Practice
The global surgical package includes preoperative evaluation and planning, the procedure, and postoperative care for the global period (0, 10, or 90 days). Fracture care and most major orthopaedic procedures carry a 90-day global.
323 words, about 2 min07Compliance: NCCI Edits, Medical Necessity, Documentation, and Payer Rules
NCCI Procedure-to-Procedure edits pair a column 1 primary code with a column 2 secondary code. The modifier indicator tells you whether an override is allowed: 0 means no, 1 means yes with an appropriate modifier, and 9 means not applicable.
304 words, about 2 min