Medical coding interviews are more technical than most healthcare BPO interviews. Expect questions on anatomy, code sets, guidelines and modifiers, and very often a written coding test with real-style charts. Experienced coders are also tested on their specialty, whether that is E/M, surgery, emergency department or risk adjustment (HCC).
Here are the questions asked most often, with concise answers. Use them to revise, but always confirm details against the current official code books and guidelines, because codes and rules are updated every year.
Basics and code sets
1. What is medical coding?
Translating diagnoses, procedures, services and supplies documented in medical records into standard codes used for billing, reporting and analysis.
2. Which code sets are used in US outpatient coding?
ICD-10-CM for diagnoses, CPT for procedures and services by providers, and HCPCS Level II for supplies, drugs, equipment and certain services. Inpatient hospital procedures use ICD-10-PCS.
3. Describe the structure of an ICD-10-CM code.
3 to 7 characters. The first character is a letter, the second is a number; characters 3 to 7 can be letters or numbers. A decimal follows the third character. The 7th character, where required, adds information such as the encounter type for injuries, and the placeholder X is used when a 7th character is needed but positions are empty.
4. What are the CPT categories?
Category I: most procedures and services (5-digit numeric). Category II: performance measurement tracking codes (alphanumeric, ending in F). Category III: temporary codes for emerging technology (ending in T).
5. What are HCPCS Level II codes?
Alphanumeric codes (a letter followed by four digits) for items such as durable medical equipment, ambulance services, drugs and supplies not covered by CPT.
Guidelines
6. What does "code to the highest level of specificity" mean?
Use the most detailed code supported by the documentation, including all required characters, rather than a general or unspecified code when more detail is documented.
7. How are uncertain diagnoses ("rule out", "probable") coded in outpatient settings?
In outpatient settings, do not code uncertain diagnoses as if confirmed; code the signs, symptoms or abnormal findings instead. Inpatient guidelines differ: at discharge, certain uncertain diagnoses may be coded as if they exist. Know which setting the role covers.
8. What is the difference between Excludes1 and Excludes2?
Excludes1 means "not coded here": the two conditions are not reported together (with specific exceptions). Excludes2 means "not included here": the excluded condition is not part of the code, but both can be reported if the patient has both.
9. What are "code first" and "use additional code" notes?
Sequencing instructions: "code first" means the underlying condition must be sequenced before the manifestation code; "use additional code" means another code should be added to fully describe the condition.
10. What is the difference between principal and first-listed diagnosis?
Principal diagnosis is used for inpatient care: the condition established after study to be chiefly responsible for the admission. First-listed diagnosis is used for outpatient encounters: the main reason for the visit.
Modifiers and edits
11. Explain modifiers 25, 59, 26 and TC.
25: significant, separately identifiable E/M service on the same day as a procedure. 59: distinct procedural service, used when services are normally bundled but were separate (payers may prefer more specific X modifiers). 26: professional component only. TC: technical component only.
12. What are LT, RT and 50?
LT and RT indicate left and right sides of the body; 50 indicates a bilateral procedure. Payer rules differ on how bilateral procedures are reported.
13. What are NCCI edits?
National Correct Coding Initiative edits identify code pairs that should not normally be billed together (procedure-to-procedure edits) and the maximum units per service (medically unlikely edits).
14. What is unbundling?
Billing separately for components that should be reported with one comprehensive code. It is incorrect and can be a compliance issue.
E/M coding
15. How are office and outpatient E/M levels selected?
Based on either medical decision making (MDM) or total time spent by the provider on the date of the encounter, according to the current CPT E/M guidelines.
16. What are the elements of medical decision making?
The number and complexity of problems addressed, the amount and complexity of data reviewed and analysed, and the risk of complications or morbidity of patient management. Two of the three elements determine the level.
17. What is the difference between a new and an established patient?
A new patient has not received professional services from the same physician, or another physician of the same specialty and subspecialty in the same group, within the past three years.
HCC and risk adjustment
18. What is HCC coding?
Hierarchical Condition Category coding groups certain diagnosis codes into categories used in risk adjustment models, which predict expected healthcare costs for patients, mainly in Medicare Advantage.
19. What is a RAF score?
The risk adjustment factor: a score based on demographics and documented conditions that reflects a patient’s expected cost relative to average.
20. What is MEAT?
A common documentation check for risk adjustment: a condition should be Monitored, Evaluated, Assessed/addressed or Treated in the note to support coding it.
21. Why must chronic conditions be documented every year?
Risk adjustment models reset each year, so chronic conditions must be documented and coded from an acceptable face-to-face encounter at least once every calendar year (the data collection year) to be counted. Know the model version your client uses, as CMS updates the HCC model.
Anatomy and terminology (quick-fire)
- Suffixes: -ectomy (removal), -otomy (incision), -ostomy (creating an opening), -itis (inflammation), -plasty (repair).
- Prefixes: hyper- (above normal), hypo- (below), brady- (slow), tachy- (fast).
- Be ready to name the chambers of the heart, the parts of the digestive system and the major bones.
The coding test: how to do well
- Read the whole chart before coding.
- Identify the reason for the encounter, confirmed diagnoses and procedures performed.
- Use the index first, then verify in the tabular list. Never code from the index alone.
- Check instructional notes, laterality and 7th characters.
- Apply modifiers only when documentation supports them.
- Manage time: do not get stuck on one chart.
Questions for experienced coders
- What is your daily productivity and accuracy in your current specialty?
- How do you handle a chart with conflicting or unclear documentation? (Answer: follow the query process with the provider; never assume.)
- Which encoder and EHR tools have you used?
- How do you keep up with annual code and guideline updates?
Frequently Asked Questions
What questions are asked in a medical coding interview?
Code set basics (ICD-10-CM, CPT, HCPCS), guideline questions, modifiers, NCCI edits, E/M leveling, anatomy and terminology, specialty questions such as HCC risk adjustment, and usually a coding test.
Is there a test in medical coding interviews?
Usually yes. Most employers give a written or system-based coding test with charts from the specialty you are being hired for.
What is the difference between ICD-10-CM and CPT?
ICD-10-CM codes describe diagnoses; CPT codes describe procedures and services performed.
What is MEAT in HCC coding?
Monitor, Evaluate, Assess/address, Treat: a common check that a condition is supported by documentation before it is coded for risk adjustment.
Do freshers get medical coding jobs?
Yes, especially certified freshers from life science, pharmacy or nursing backgrounds, though experienced coders have more options.