ICD 10 Study Guide 2026
Everything you need to pass the ICD 10 exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 ICD 10 Exam Format at a Glance
📚 ICD 10 Topics to Study (22)
✍️ Sample ICD 10 Questions & Answers
1. How should you approach questions you find difficult during an exam?
Moving past difficult questions ensures you answer all questions you know, then return to harder ones with remaining time and possibly new insight from other questions.
2. What does the first character of an ICD-10-CM code represent?
The first character is always a letter that corresponds to a specific chapter of the ICD-10-CM classification, such as J for respiratory diseases.
3. What is the principal diagnosis?
The principal diagnosis is determined after evaluation and is the condition that prompted the inpatient admission, which may differ from the admitting diagnosis.
4. How many characters does every valid ICD-10-PCS code contain?
Every ICD-10-PCS code has exactly 7 alphanumeric characters. Each position has a set meaning, such as section, body system and root operation. ICD-10-CM codes can be 3 to 7 characters, but PCS codes are always 7.
5. What ICD-10-CM chapter covers diseases of the musculoskeletal system?
Chapter 13 covers diseases of the musculoskeletal system and connective tissue using M codes (M00-M99), including arthritis, back pain, and osteoporosis.
6. What ICD-10-CM code range covers neoplasms?
Neoplasms (tumors/cancers) are classified in Chapter 2 using codes C00-D49, with C codes for malignant and D codes for benign/uncertain behavior.
🎯 Free ICD 10 Practice Tests
📖 ICD 10 Guides & Articles
What Practice Test Geeks adds beyond an AI chat for ICD 10
An AI chatbot can quiz you, but it can't reproduce the exam conditions or keep your record. Here you get:
- A timed, full-length ICD 10 mock exam — 75 questions in 210 minutes with a 80% pass mark, modeled on the official exam's question count and time limit, followed by a score report broken down by exam domain.
- A fixed ICD 10 question bank: the same test every attempt, so your score is comparable from one try to the next instead of changing with every regenerated quiz.
- Progress saved on your device: completed tests, scores and missed questions stay in My Progress, so you can retake only what you got wrong.
- A printable ICD 10 cheat sheet you can print or save as a PDF.
- ICD 10 flashcards built from the same question bank.
- Free ICD 10 practice tests with the correct answer shown after each question.
How this page was made: written with AI tools and published by Nathan Beja, founder of Practice Test Geeks, who is responsible for its content. Exam facts are checked against the official sources listed below. Not reviewed by a subject-matter expert. Editorial policy
Sources & references
Exam facts on this page (fees, format, dates, passing scores) are checked against these official sources; the date is our last check. Editorial policy
- cms.gov — Test delivery, exam format, passing score, retake policy, time limit · verified Sep 2026