D521 Medical Coding 2026 Exam (200+ Questions) – D521 ICD-10-CM, CPT, HCPCS & Billing Concepts Q&A – WGU

This document provides a comprehensive set of over 200 exam-style questions and answers for D521 Introduction to Medical Coding 2026. It covers fundamental medical coding concepts including ICD-10-CM and ICD-10-PCS classification systems, CPT and HCPCS coding, healthcare documentation, reimbursement methods, and revenue cycle management. The content is structured in a clear Q&A format to support efficient learning and exam preparation. The material emphasizes core coding principles and real-world healthcare applications. Topics include diagnosis definitions (morbidity, mortality, comorbidity), coding systems (ICD revisions, CPT structure), healthcare organizations (AHIMA, AHA, WHO), and billing processes such as claim adjudication, reimbursement models (PPS, IPPS, OPPS), and revenue cycle stages. For example, early sections (pages 1–4) introduce foundational terminology and coding systems, while later sections (pages 7–14) focus on procedural coding, billing workflows, and reimbursement strategies. This document is particularly suitable for: Students enrolled in D521 Introduction to Medical Coding (WGU) Health information management (HIM) students Medical billing and coding certification candidates (CPC, CCS) Healthcare administration and allied health students Beginners learning ICD-10, CPT, and reimbursement systems The content aligns closely with standard textbooks such as Step-by-Step Medical Coding by Carol J. Buck and AHIMA coding resources, making it an excellent standalone revision guide and a strong supplement for coursework and certification preparation. Keywords: medical coding exam questions, ICD 10 CM coding, ICD 10 PCS procedures, CPT coding system, HCPCS level II, medical billing concepts, revenue cycle management, diagnosis coding, healthcare documentation, reimbursement methods, claim adjudication, coding guidelines, health information management, coding certification prep