CCS Medical Coding Guidelines & Compliance 2 — Questions and Answers
Question 1: According to the ICD-10-CM Official Guidelines, what is the definition of the principal diagnosis for inpatient coding?
- The diagnosis that is the patient's primary chronic condition
- The condition established after study to be chiefly responsible for occasioning the admission (Correct answer)
- The first diagnosis listed by the attending physician in the discharge summary
- The diagnosis with the highest DRG weight
Correct answer: The condition established after study to be chiefly responsible for occasioning the admission
Per UHDDS and ICD-10-CM Guidelines, the principal diagnosis is 'the condition established after study to be chiefly responsible for occasioning the admission to the hospital for care.'
The Uniform Hospital Discharge Data Set (UHDDS) definition, adopted by ICD-10-CM Guidelines, specifies that the principal diagnosis is established after the full workup is complete - it may differ from the admitting diagnosis. For example, a patient admitted for chest pain found to have acute MI has acute MI as the principal diagnosis, not chest pain. This is a fundamental guideline that drives DRG assignment and must be applied correctly by CCS candidates.
Question 2: Under ICD-10-CM Official Coding Guidelines, when two or more diagnoses meet the definition of principal diagnosis, how should the coder proceed?
- Always code the condition with the highest DRG weight first
- Either condition may be sequenced first (Correct answer)
- The admitting diagnosis must be listed as principal
- Query the physician to select one principal diagnosis
Correct answer: Either condition may be sequenced first
When two or more conditions equally meet the definition of principal diagnosis, the Official Guidelines state that either may be sequenced first as principal diagnosis.
ICD-10-CM Official Guidelines Section II.C states that when two or more diagnoses equally meet the criteria for principal diagnosis as defined in UHDDS, either may be sequenced as principal. The coder should not manipulate sequencing to maximize DRG reimbursement (that would be upcoding). If one diagnosis has an instructional note ('code first') or a sequencing guideline, those override this rule. Physician query is not required when guidelines explicitly permit either sequence.
Question 3: What is the ICD-10-CM coding guideline for signs and symptoms that are integral to a confirmed disease?
- Code both the sign/symptom and the confirmed disease
- Do not code signs and symptoms routinely reported with the confirmed disease (Correct answer)
- Code the sign/symptom as the principal diagnosis and the disease as secondary
- Query the physician before coding any symptom
Correct answer: Do not code signs and symptoms routinely reported with the confirmed disease
Per ICD-10-CM Guidelines, signs and symptoms that are routinely associated with a disease process (integral to the disease) should not be assigned as additional codes.
ICD-10-CM Official Guidelines Section I.C.18 and general guidelines state that signs and symptoms integral to a confirmed disease should not be coded additionally. For example, chest pain is integral to acute MI and should not be separately coded. However, signs and symptoms NOT routinely associated - such as a patient with pneumonia who also has a separate complaint of hematuria - should be coded. This guideline prevents redundant and misleading diagnosis reporting.
Question 4: Under the ICD-10-CM Official Guidelines, the term 'code also' means:
- An additional code is required to fully describe the condition
- An additional code should be reported if applicable and present (Correct answer)
- The code following should always be sequenced first
- Only one code may be assigned for this condition
Correct answer: An additional code should be reported if applicable and present
'Code also' is an instructional note indicating that an additional code may be assigned if the condition is present and applicable - it is not always mandatory.
ICD-10-CM conventions include instructional notes to guide code selection. 'Code also' instructs the coder to assign an additional code if the condition is documented and clinically present. It is not an absolute requirement like 'use additional code' (which is mandatory when the condition is present) or 'code first' (which mandates sequencing). Understanding the nuanced differences between 'code also,' 'use additional code,' and 'code first' is tested on the CCS exam.
Question 5: A patient is treated for a fractured femur resulting from a fall from a ladder at a construction site. In addition to the fracture code, what additional code type is required by ICD-10-CM?
- A Z code for the occupational setting
- An external cause code (V00-Y99) for the mechanism and place of injury (Correct answer)
- A code for osteoporosis as the underlying cause
- A social determinants of health (SDOH) code
Correct answer: An external cause code (V00-Y99) for the mechanism and place of injury
ICD-10-CM Guidelines require external cause codes (Chapter 20, V00-Y99) to capture the mechanism of injury (fall from ladder) and place of occurrence (construction site) when injuries are coded.
ICD-10-CM Chapter 20 (External Causes of Morbidity, V00-Y99) provides codes for the mechanism of injury, place of occurrence, activity, and patient status. For this case: W11.XXXA (fall on and from ladder, initial encounter), Y93.89 (activity, other specified), Y99.0 (civilian activity done for income). Place of occurrence codes (Y92.61x for construction site) are also reported. External cause codes are secondary diagnoses - never principal - and are used for injury epidemiology and liability tracking.
Question 6: What does the ICD-10-CM guideline state about coding 'probable' or 'suspected' diagnoses in the outpatient setting?
- Code the probable diagnosis as if confirmed, same as inpatient
- Do not code the probable diagnosis; code the signs, symptoms, or condition documented (Correct answer)
- Query the physician to confirm before coding
- Code both the probable diagnosis and the presenting symptom together
Correct answer: Do not code the probable diagnosis; code the signs, symptoms, or condition documented
In outpatient settings, ICD-10-CM Guidelines prohibit coding probable, suspected, or 'rule out' diagnoses. Code the documented sign, symptom, or finding instead.
This is a critical guideline distinction: For inpatient coding, probable, suspected, or 'rule out' diagnoses documented at discharge as 'probable' or 'suspected' may be coded as if confirmed (ICD-10-CM Guidelines Section II.H). For outpatient coding (Sections IV.D-E), coders must code the highest degree of certainty - only confirmed diagnoses, or the sign/symptom if no confirmed diagnosis. This distinction is heavily tested on the CCS exam as it applies differently to the inpatient vs. outpatient sections.
CCS Medical Coding Guidelines & Compliance 2
According to the ICD-10-CM Official Guidelines, what is the definition of the principal diagnosis for inpatient coding?