- A patient presents with chest pain. After a complete workup, the physician's final documented diagnosis is "chest pain, etiology undetermined." For this outpatient encounter, which code is reported?
Answer: Chest pain (R07.9 or specific subcategory)
For outpatient encounters, signs and symptoms are coded when no definitive diagnosis has been confirmed. The physician's documentation of "chest pain, etiology undetermined" means no confirmed diagnosis exists, and the symptom code (R07 series for chest pain) is the first-listed diagnosis. "Probable," "possible," or "undetermined" diagnoses are not coded as confirmed in the outpatient setting.
- The ICD-10-CM Official Guidelines include four sections. Which section addresses general coding guidelines applicable to all settings?
Answer: Section I
ICD-10-CM Official Guidelines are divided into four sections: Section I covers general coding guidelines and chapter-specific guidelines applicable across all settings. Section II addresses selection of the principal diagnosis for inpatient admissions. Section III addresses reporting additional diagnoses for inpatient settings. Section IV addresses diagnostic coding and reporting for outpatient services.
- A coder encounters the ICD-10-CM notation "Code also." What does this instruction require?
Answer: Both codes should be reported, with sequencing determined by the reason for the encounter
The "code also" note in ICD-10-CM instructs that a second code should be reported when the condition is present. Unlike "code first" (which mandates sequencing), "code also" does not specify a sequencing requirement — the order is determined by the circumstances of the encounter and the applicable sequencing guidelines.
- A patient has both essential hypertension and stage 3 chronic kidney disease. There is no documentation of a causal relationship. How are these conditions coded?
Answer: I12.9 and N18.3 — ICD-10-CM presumes a causal relationship between hypertension and CKD when both conditions coexist
Per ICD-10-CM Official Guidelines (Section I.C.9), when both hypertension and chronic kidney disease are present, a cause-and-effect relationship is presumed and the combination code from category I12 is always used — regardless of whether the provider explicitly documents causality. I12.9 (Hypertensive chronic kidney disease with stage 1–4 or unspecified CKD) and N18.3 (CKD, stage 3) are both reported. Separate reporting of I10 and N18.3 without the combination code is incorrect when both conditions coexist.
- A patient with type 2 diabetes is seen for a new diagnosis of mild non-proliferative diabetic retinopathy with macular edema, right eye. Which ICD-10-CM code should be reported?
Answer: E11.3211 — type 2 diabetes with mild nonproliferative diabetic retinopathy with macular edema, right eye
ICD-10-CM E11.3211 covers type 2 diabetes mellitus with mild nonproliferative diabetic retinopathy with macular edema, right eye. The combination code captures the diabetes type, the retinopathy severity (mild nonproliferative), the presence of macular edema, and the specific eye — all in a single code. Separate diabetes and eye codes are not needed. E11.9 does not capture the retinopathy or macular edema, and H35.81 is not a diabetic retinopathy code.
- The Tabular List shows an Excludes2 note beneath a code. A patient has both conditions listed. Can both codes be reported?
Answer: Yes — Excludes2 indicates the excluded condition is not included in the code but may be reported separately when both conditions coexist
An Excludes2 note means the excluded condition is not part of the condition represented by the code, but a patient may have both conditions simultaneously. When both conditions are present and documented, both codes may be reported. This is the key distinction from Excludes1, where simultaneous reporting is never permitted.
- A patient is being treated for a condition the physician documents as "impending respiratory failure." ICD-10-CM guidelines address how to code impending or threatened conditions. What is the correct approach?
Answer: Refer to the ICD-10-CM Alphabetic Index — if the condition is indexed as "impending," use that code; if not, report the current signs and symptoms
The ICD-10-CM Official Guidelines state that if the Alphabetic Index provides a subterm for "impending" or "threatened," that entry should be used. If no such entry exists, the condition is coded based on the current signs and symptoms that are actually present. The condition is not coded as if it exists unless it is specifically listed as such in the Index.
- An ICD-10-CM code requires a placeholder character. The code structure is T36.0X1A (poisoning by penicillins, accidental). What is the purpose of the "X" in this code?
Answer: X is a placeholder to allow for future expansion and to maintain the correct code length for 7th character assignment
In ICD-10-CM, the letter X is used as a placeholder character to fill positions in codes that require a specific length before a 7th character can be assigned. Without the placeholder, the 7th character would not fall in the correct position. Codes requiring a 7th character must have all positions filled, using X when no other character applies for that position.
- A patient with a history of colon cancer, now in remission, is seen for a follow-up surveillance colonoscopy. No current malignancy is found. Which ICD-10-CM code is reported as the first-listed diagnosis?
Answer: Z08 — encounter for follow-up examination after completed treatment for malignant neoplasm
Z08 (encounter for follow-up examination after completed treatment for malignant neoplasm) is the first-listed diagnosis for a surveillance visit following cancer treatment when no current malignancy exists. The personal history code (Z85 series) is reported as an additional diagnosis. C18.9 is not reported since the cancer is in remission and not currently active.
- A patient is seen for a condition described in the documentation as "NOS." What does NOS mean in ICD-10-CM, and how does it affect code selection?
Answer: NOS means "not otherwise specified" and indicates the coder should assign the unspecified or default code for that condition
In ICD-10-CM, "NOS" stands for "Not Otherwise Specified" — equivalent to "unspecified." When a provider documents a condition without further specification, the NOS or unspecified code is assigned. Coders should not assume additional specificity beyond what is documented; however, they may query the physician for clarification before defaulting to an unspecified code.
- A patient fractured her left wrist 6 months ago and is now being seen for persistent wrist stiffness as a result. The fracture has healed. Which 7th character is used for this sequela encounter?
Answer: S
The 7th character "S" (sequela) is used for complications or conditions that arise as a direct result of an injury, after the active phase of treatment has ended. The sequela code is reported along with the injury code using the "S" 7th character to identify the late effect. "D" is for routine subsequent encounters during active healing, not for sequelae after the injury has resolved.
- A patient sustains multiple injuries in a car accident: a closed femur fracture and a laceration of the spleen. Both conditions are treated during the same admission. How many ICD-10-CM codes are required?
Answer: Two codes — one for each injury, sequencing determined by the most severe or most resource-intensive condition
When a patient sustains multiple injuries, each injury is coded separately. ICD-10-CM does not have combination codes for multiple traumatic injuries across different body systems. The most severe injury or the one chiefly responsible for the admission is sequenced first. Both the femur fracture and the splenic laceration require their own specific ICD-10-CM codes.
- The ICD-10-CM Alphabetic Index lists a main term with subterms. A coder finds the main term but cannot locate the specific subterm for the documented condition. What is the correct next step?
Answer: Check cross-references, synonyms, or "see also" notes in the Alphabetic Index before proceeding to the Tabular List
The correct ICD-10-CM coding process requires reviewing the Alphabetic Index first, then verifying in the Tabular List. If the specific subterm is not found, the coder should check cross-references ("see," "see also"), synonyms, and eponyms in the Index before proceeding to the Tabular List. A code should never be assigned based solely on the Index or the Tabular List alone — both must be used.
- A patient is diagnosed with acute and chronic sinusitis affecting the same sinus. ICD-10-CM provides a combination code for acute-on-chronic sinusitis. What is the correct coding approach?
Answer: Report the combination code for acute and chronic sinusitis
When ICD-10-CM provides a combination code that captures both the acute and chronic components of a condition, the combination code should be reported. Reporting separate acute and chronic codes when a single combination code exists is incorrect coding. Coders should always check the Alphabetic Index and Tabular List for combination codes before assigning multiple codes.
- A patient is diagnosed with cellulitis of the right lower leg. ICD-10-CM requires laterality in code selection. Which code correctly identifies this condition?
Answer: L03.115
ICD-10-CM L03.115 covers cellulitis of the right lower limb. L03.116 is cellulitis of the left lower limb; L03.119 is cellulitis of unspecified lower limb. When laterality is documented, the specific laterality code must be selected. Reporting an unspecified code (L03.119) when the side is documented constitutes incomplete coding.
- A patient is seen for a condition that is documented as "possible pneumonia." This is an inpatient admission, and the condition is still being worked up at discharge. How is this coded for inpatient purposes?
Answer: The possible pneumonia is coded as if confirmed, per inpatient coding guidelines
ICD-10-CM Official Guidelines for inpatient coding (Section II) permit coding of "possible," "probable," "suspected," or "likely" diagnoses as if established when they remain under investigation at the time of discharge. This is the opposite of outpatient guidelines, where only confirmed diagnoses or symptoms are reported. For the inpatient setting, "possible pneumonia" is coded as pneumonia.
- A patient is treated for a deep vein thrombosis (DVT) of the left femoral vein. ICD-10-CM requires specificity for DVT coding. Which element is NOT required for accurate DVT code selection in ICD-10-CM?
Answer: The patient's age at onset of DVT
ICD-10-CM DVT codes require: laterality (left/right/bilateral), the specific vessel involved (e.g., femoral, popliteal), and the acuity (acute vs. chronic). Patient age is not an axis of classification in DVT code selection. Accurate reporting requires all three documented clinical elements to avoid use of an unspecified code.
- A physician documents "hypertensive heart disease with heart failure." ICD-10-CM provides a combination code for this condition. Which code category captures both hypertension and heart failure together?
Answer: I11.0, with an additional code from the I50 series to specify the type of heart failure
When hypertensive heart disease is accompanied by heart failure, ICD-10-CM code I11.0 (Hypertensive heart disease with heart failure) is used — the specific subcategory within I11 that captures the heart failure component. Per Official Guidelines, an additional code from category I50 is required to identify the type of heart failure. I10 captures hypertension alone without heart disease; I11.9 is hypertensive heart disease without heart failure; I13 is for hypertensive heart and chronic kidney disease combined.
- A patient is seen for a follow-up visit following treatment for a resolved urinary tract infection. No current infection is present. Which type of ICD-10-CM code is most appropriate as the first-listed diagnosis?
Answer: An aftercare code (Z09)
Z09 (encounter for follow-up examination after completed treatment for conditions other than malignant neoplasm) is appropriate when a patient returns for follow-up after a condition has been resolved and no current condition exists. Personal history codes (Z87) are used to report past conditions that no longer exist and are not receiving treatment. Z09 specifically captures the follow-up visit context.
- The ICD-10-CM category "NEC" appears in the Tabular List. What does NEC mean, and how is it different from NOS?
Answer: NEC means "not elsewhere classified" — the condition exists but there is no more specific code available; NOS means "not otherwise specified" — the condition is unspecified
NEC (Not Elsewhere Classified) means there is no more specific code in ICD-10-CM for the documented condition, even though the documentation is specific. "NOS" (Not Otherwise Specified) means the documentation lacks specificity. NEC = specific condition, no specific code available. NOS = unspecified condition. Understanding this distinction guides accurate code assignment.
