Medical Coding Interview Questions & Answers for Freshers (2026 Guide)

### Q1: What is Medical Coding and why is it essential? **Model Answer:** Medical coding is the transformation of healthcare diagnoses, procedures, medical services, and equipment into universal alphanumeric codes. In US healthcare, it establishes medical necessity, standardizes clinical documentation, and drives insurance claim reimbursement between healthcare providers and third-party payers. ### Q2: What is the fundamental difference between ICD-10-CM, CPT, and HCPCS? **Model Answer:** - **ICD-10-CM (Clinical Modification)**: Diagnosis coding system developed by CDC/WHO. Explains **WHY** the patient sought healthcare (e.g., J45.909 for Unspecified asthma). - **CPT (Current Procedural Terminology)**: Maintained by the American Medical Association (AMA). Explains **WHAT** service, diagnostic test, or surgical procedure was performed by the healthcare provider (e.g., 99213 for Office outpatient visit). - **HCPCS Level II**: Maintained by CMS. Codes non-physician services, ambulance transportation, prosthetics, orthotics, and durable medical equipment (DME).

### Q3: Explain the structure of an ICD-10-CM code. **Model Answer:** An ICD-10-CM code consists of 3 to 7 characters: - **Character 1**: Always an alphabet (except U). - **Characters 2 and 3**: Numeric characters representing the category. - **Characters 4 through 6**: Numeric or alphabetic, specifying etiology, anatomical site, or manifestation. - **Character 7**: Extension representing the episode of care (A = Initial encounter, D = Subsequent encounter, S = Sequela). ### Q4: What is the purpose of the dummy placeholder character 'X'? **Model Answer:** The letter 'X' is used as a placeholder in certain 6-character codes that require a 7th character extension. It preserves code structure when a specific subcategory does not have characters 4, 5, or 6, allowing future expansions without breaking existing electronic billing formats (e.g., T36.0X1A). ### Q5: What is the difference between 'Excludes1' and 'Excludes2'? **Model Answer:** - **Excludes1 ('NOT CODED HERE!')**: Pure exclusion rule. The code excluded and the code listed can NEVER be reported together on the same claim because they are mutually exclusive. - **Excludes2 ('NOT INCLUDED HERE')**: Indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. Both codes may be billed together if documented.

### Q6: What is a Modifier and why is it used in CPT coding? **Model Answer:** A modifier is a two-character numeric or alphanumeric code appended to a CPT code to report that a service or procedure has been altered by some specific circumstance, without changing the fundamental definition of the code. ### Q7: Explain Modifier 25 and Modifier 59. **Model Answer:** - **Modifier 25**: Significant, Separately Identifiable Evaluation and Management (E/M) Service by the Same Physician on the Same Day of the Procedure or Other Service. Example: A diabetic patient comes for routine E/M and the doctor also performs a minor skin excision. Modifier 25 is attached to the E/M code. - **Modifier 59**: Distinct Procedural Service. Identifies procedures or services that are not normally reported together, but were distinct or independent under the clinical circumstances (different site, different organ, or separate incision).

### Q8: Describe the stages of the US Healthcare Revenue Cycle (RCM). **Model Answer:** 1. **Patient Registration & Eligibility Verification**: Pre-authorizations and insurance coverage checks. 2. **Clinical Encounter & Documentation**: Physician charts notes in Electronic Health Records (EHR). 3. **Medical Coding & Charge Capture**: Certified coders assign ICD-10-CM and CPT codes. 4. **Claim Scrubbing & Submission**: Electronic EDI 837 claim transmission via clearinghouse. 5. **Payment Posting & Denial Management**: Electronic Remittance Advice (ERA/835) processing, appeals for rejected claims, and patient billing.

### Q9: What are common root words, prefixes, and suffixes asked in coding interviews? **Model Answer:** - **Prefixes**: Dys- (painful/abnormal), Brady- (slow), Tachy- (rapid), Sub- (below), Poly- (many). - **Roots**: Nephr/o (Kidney), Hepat/o (Liver), Cholecyst/o (Gallbladder), Encephal/o (Brain), Arthr/o (Joint). - **Suffixes**: -itis (inflammation), -ectomy (surgical removal), -otomy (cutting into/incision), -ostomy (creating an artificial opening), -plasty (surgical repair).

### Scenario A: Acute vs Chronic Sequencing *Question:* "A patient presents with acute and chronic cholecystitis. How do you sequence the diagnosis codes?" *Answer:* According to ICD-10-CM Official Guidelines for Coding and Reporting (Section I.B.8): If the same condition is described as both acute (subacute) and chronic, and separate subentries exist in the Alphabetic Index at the same indentation level, **code both and sequence the acute (subacute) code first**. ### Scenario B: Signs and Symptoms vs Confirmed Diagnosis *Question:* "A patient presents with severe right upper quadrant abdominal pain. Ultrasound confirms acute cholelithiasis. Do you code both the pain and the gallstones?" *Answer:* **No, code only the cholelithiasis.** Under ICD-10 guidelines, signs and symptoms that are routinely associated with a confirmed disease process should not be assigned additional codes once the definitive diagnosis has been established.