Certified Outpatient Coder (COC®) Exam Prep 2026
Updated Practice Questions — Comprehensive Outpatient
Coding Review Detailed Explanations, Verified Answers,
Complete Success Workbook
SECTION 1: OUTPATIENT ICD-10-CM CODING
Question 1
A 65-year-old patient is seen in the hospital outpatient department for evaluation of
shortness of breath and chest pain. The physician's final diagnosis is "acute
bronchitis" after ruling out pneumonia and myocardial infarction. What is the
correct ICD-10-CM diagnosis code?
A) R06.02 (Shortness of breath)
B) R07.9 (Chest pain, unspecified)
C) J20.9 (Acute bronchitis, unspecified)
D) J44.0 (Chronic obstructive pulmonary disease with acute lower respiratory
infection)
Rationale: The final diagnosis of acute bronchitis (J20.9) is the correct code.
"Rule out" diagnoses should not be coded as if they exist. Symptoms (shortness of
breath, chest pain) that are integral to the definitive diagnosis should not be coded
separately. In outpatient coding, only confirmed diagnoses are coded.
Question 2
A patient with type 2 diabetes mellitus is seen in the outpatient clinic for diabetic
neuropathy affecting the lower extremities. The physician documents a cause-and-
effect relationship. What is the correct ICD-10-CM diagnosis code?
A) E11.9 (Type 2 diabetes mellitus without complications)
B) E11.40 (Type 2 diabetes mellitus with diabetic neuropathy, unspecified)
C) E11.42 (Type 2 diabetes mellitus with diabetic polyneuropathy)
D) G62.9 (Polyneuropathy, unspecified)
Rationale: When diabetes is the cause of a condition, the diabetes code with the
manifestation is used as the primary code. E11.40 is the correct code for type 2
,diabetes with diabetic neuropathy. The neuropathy is a manifestation of the
diabetes and should not be coded separately with a G code.
Question 3
A patient is seen in the outpatient clinic for a routine follow-up after a kidney
transplant. The patient is stable and is being seen for medication management.
What is the correct ICD-10-CM diagnosis code?
A) Z94.0 (Kidney transplant status)
B) Z94.0 (Kidney transplant status) and Z79.899 (Other long-term (current)
drug therapy)
C) T86.10 (Unspecified complication of kidney transplant)
D) Z00.00 (Encounter for general adult medical examination without abnormal
findings)
Rationale: A patient with a kidney transplant should have Z94.0 (Kidney
transplant status) coded to indicate the transplant. If the patient is on long-term
immunosuppressive therapy, Z79.899 may also be coded. Routine follow-up after
transplant without complications is coded with the transplant status code.
Question 4
A patient is seen in the emergency department for a laceration of the left forearm.
The physician repairs the laceration with sutures. What is the correct ICD-10-CM
diagnosis code for the injury?
A) S51.811A (Laceration without foreign body of right forearm, initial encounter)
B) S51.812A (Laceration without foreign body of left forearm, initial
encounter)
C) S51.819A (Laceration without foreign body of unspecified forearm, initial
encounter)
D) S51.812D (Laceration without foreign body of left forearm, subsequent
encounter)
Rationale: The correct code is S51.812A — laceration without foreign body of
the left forearm, initial encounter (A). The 7th character "A" indicates initial
encounter for the injury. Laterality (left vs. right) is essential for accurate coding.
,The "D" character indicates subsequent encounter and is not appropriate for the
initial treatment.
Question 5
A patient is seen in the outpatient clinic for a urinary tract infection (UTI). The
physician documents "acute cystitis." What is the correct ICD-10-CM diagnosis
code?
A) N39.0 (Urinary tract infection, site not specified)
B) N30.00 (Acute cystitis without hematuria)
C) N30.01 (Acute cystitis with hematuria)
D) N30.90 (Cystitis, unspecified)
Rationale: Acute cystitis is coded with N30.00 when there is no hematuria
documented. If hematuria is present, N30.01 would be used. N39.0 is used when
the site of the UTI is not specified.
Question 6
A patient is seen in the outpatient clinic for hypertension. The physician documents
"essential hypertension." What is the correct ICD-10-CM diagnosis code?
A) I10 (Essential (primary) hypertension)
B) I10 (Essential (primary) hypertension)
C) I15.0 (Renovascular hypertension)
D) I15.9 (Secondary hypertension, unspecified)
Rationale: I10 is the correct code for essential (primary) hypertension. Secondary
hypertension (I15) is coded when the hypertension is due to another condition
(e.g., renal disease, endocrine disorders).
Question 7
A patient is seen in the emergency department for a migraine headache. The
physician documents "migraine with aura." What is the correct ICD-10-CM
diagnosis code?
A) G43.009 (Migraine without aura, not intractable, without status migrainosus)
B) G43.109 (Migraine with aura, not intractable, without status migrainosus)
, C) R51 (Headache)
D) G44.1 (Vascular headache, not elsewhere classified)
Rationale: Migraine with aura is coded with G43.109 when it is not intractable
and without status migrainosus. G43.009 is for migraine without aura. Headache
(R51) is a symptom and should not be coded when a definitive diagnosis of
migraine is documented.
Question 8
A patient is seen in the outpatient clinic for follow-up of breast cancer. The patient
is currently in remission and is being seen for surveillance. What is the correct
ICD-10-CM diagnosis code?
A) C50.9 (Malignant neoplasm of breast, unspecified)
B) Z08 (Encounter for follow-up examination after completed treatment for
malignant neoplasm)
C) Z85.3 (Personal history of malignant neoplasm of breast)
D) Z80.3 (Family history of malignant neoplasm of breast)
Rationale: When a patient is being seen for follow-up after completed
treatment for cancer, the correct code is Z08. Z85.3 is used for personal history of
breast cancer when the patient is not being actively followed for surveillance.
C50.9 is used when the cancer is active.
Question 9
A patient is seen in the outpatient clinic for dehydration. The physician documents
"dehydration due to viral gastroenteritis." What is the correct ICD-10-CM coding
approach?
A) E86.0 (Dehydration)
B) E86.0 (Dehydration) and A08.4 (Viral intestinal infection, unspecified)
C) A08.4 (Viral intestinal infection, unspecified)
D) R11.2 (Nausea with vomiting, unspecified)
Rationale: When a patient is seen for dehydration due to another condition, both
codes should be reported. The dehydration (E86.0) is the reason for the encounter,
and the underlying cause (viral gastroenteritis, A08.4) is coded as a secondary
diagnosis. The combination provides a complete clinical picture.
Updated Practice Questions — Comprehensive Outpatient
Coding Review Detailed Explanations, Verified Answers,
Complete Success Workbook
SECTION 1: OUTPATIENT ICD-10-CM CODING
Question 1
A 65-year-old patient is seen in the hospital outpatient department for evaluation of
shortness of breath and chest pain. The physician's final diagnosis is "acute
bronchitis" after ruling out pneumonia and myocardial infarction. What is the
correct ICD-10-CM diagnosis code?
A) R06.02 (Shortness of breath)
B) R07.9 (Chest pain, unspecified)
C) J20.9 (Acute bronchitis, unspecified)
D) J44.0 (Chronic obstructive pulmonary disease with acute lower respiratory
infection)
Rationale: The final diagnosis of acute bronchitis (J20.9) is the correct code.
"Rule out" diagnoses should not be coded as if they exist. Symptoms (shortness of
breath, chest pain) that are integral to the definitive diagnosis should not be coded
separately. In outpatient coding, only confirmed diagnoses are coded.
Question 2
A patient with type 2 diabetes mellitus is seen in the outpatient clinic for diabetic
neuropathy affecting the lower extremities. The physician documents a cause-and-
effect relationship. What is the correct ICD-10-CM diagnosis code?
A) E11.9 (Type 2 diabetes mellitus without complications)
B) E11.40 (Type 2 diabetes mellitus with diabetic neuropathy, unspecified)
C) E11.42 (Type 2 diabetes mellitus with diabetic polyneuropathy)
D) G62.9 (Polyneuropathy, unspecified)
Rationale: When diabetes is the cause of a condition, the diabetes code with the
manifestation is used as the primary code. E11.40 is the correct code for type 2
,diabetes with diabetic neuropathy. The neuropathy is a manifestation of the
diabetes and should not be coded separately with a G code.
Question 3
A patient is seen in the outpatient clinic for a routine follow-up after a kidney
transplant. The patient is stable and is being seen for medication management.
What is the correct ICD-10-CM diagnosis code?
A) Z94.0 (Kidney transplant status)
B) Z94.0 (Kidney transplant status) and Z79.899 (Other long-term (current)
drug therapy)
C) T86.10 (Unspecified complication of kidney transplant)
D) Z00.00 (Encounter for general adult medical examination without abnormal
findings)
Rationale: A patient with a kidney transplant should have Z94.0 (Kidney
transplant status) coded to indicate the transplant. If the patient is on long-term
immunosuppressive therapy, Z79.899 may also be coded. Routine follow-up after
transplant without complications is coded with the transplant status code.
Question 4
A patient is seen in the emergency department for a laceration of the left forearm.
The physician repairs the laceration with sutures. What is the correct ICD-10-CM
diagnosis code for the injury?
A) S51.811A (Laceration without foreign body of right forearm, initial encounter)
B) S51.812A (Laceration without foreign body of left forearm, initial
encounter)
C) S51.819A (Laceration without foreign body of unspecified forearm, initial
encounter)
D) S51.812D (Laceration without foreign body of left forearm, subsequent
encounter)
Rationale: The correct code is S51.812A — laceration without foreign body of
the left forearm, initial encounter (A). The 7th character "A" indicates initial
encounter for the injury. Laterality (left vs. right) is essential for accurate coding.
,The "D" character indicates subsequent encounter and is not appropriate for the
initial treatment.
Question 5
A patient is seen in the outpatient clinic for a urinary tract infection (UTI). The
physician documents "acute cystitis." What is the correct ICD-10-CM diagnosis
code?
A) N39.0 (Urinary tract infection, site not specified)
B) N30.00 (Acute cystitis without hematuria)
C) N30.01 (Acute cystitis with hematuria)
D) N30.90 (Cystitis, unspecified)
Rationale: Acute cystitis is coded with N30.00 when there is no hematuria
documented. If hematuria is present, N30.01 would be used. N39.0 is used when
the site of the UTI is not specified.
Question 6
A patient is seen in the outpatient clinic for hypertension. The physician documents
"essential hypertension." What is the correct ICD-10-CM diagnosis code?
A) I10 (Essential (primary) hypertension)
B) I10 (Essential (primary) hypertension)
C) I15.0 (Renovascular hypertension)
D) I15.9 (Secondary hypertension, unspecified)
Rationale: I10 is the correct code for essential (primary) hypertension. Secondary
hypertension (I15) is coded when the hypertension is due to another condition
(e.g., renal disease, endocrine disorders).
Question 7
A patient is seen in the emergency department for a migraine headache. The
physician documents "migraine with aura." What is the correct ICD-10-CM
diagnosis code?
A) G43.009 (Migraine without aura, not intractable, without status migrainosus)
B) G43.109 (Migraine with aura, not intractable, without status migrainosus)
, C) R51 (Headache)
D) G44.1 (Vascular headache, not elsewhere classified)
Rationale: Migraine with aura is coded with G43.109 when it is not intractable
and without status migrainosus. G43.009 is for migraine without aura. Headache
(R51) is a symptom and should not be coded when a definitive diagnosis of
migraine is documented.
Question 8
A patient is seen in the outpatient clinic for follow-up of breast cancer. The patient
is currently in remission and is being seen for surveillance. What is the correct
ICD-10-CM diagnosis code?
A) C50.9 (Malignant neoplasm of breast, unspecified)
B) Z08 (Encounter for follow-up examination after completed treatment for
malignant neoplasm)
C) Z85.3 (Personal history of malignant neoplasm of breast)
D) Z80.3 (Family history of malignant neoplasm of breast)
Rationale: When a patient is being seen for follow-up after completed
treatment for cancer, the correct code is Z08. Z85.3 is used for personal history of
breast cancer when the patient is not being actively followed for surveillance.
C50.9 is used when the cancer is active.
Question 9
A patient is seen in the outpatient clinic for dehydration. The physician documents
"dehydration due to viral gastroenteritis." What is the correct ICD-10-CM coding
approach?
A) E86.0 (Dehydration)
B) E86.0 (Dehydration) and A08.4 (Viral intestinal infection, unspecified)
C) A08.4 (Viral intestinal infection, unspecified)
D) R11.2 (Nausea with vomiting, unspecified)
Rationale: When a patient is seen for dehydration due to another condition, both
codes should be reported. The dehydration (E86.0) is the reason for the encounter,
and the underlying cause (viral gastroenteritis, A08.4) is coded as a secondary
diagnosis. The combination provides a complete clinical picture.
