Certified Professional Coder (CPC) Quiz: Apply Endocrine Coding Rules
20 questions · exam conditions
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Apply Endocrine Coding RulesQuestion 1 of 20

A surgeon removes a pituitary adenoma via a transsphenoidal approach. In which CPT® code range are transsphenoidal pituitary surgery codes found?

61546-61548
61500-61516
60600-60605
62165
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Certified Professional Coder (CPC) Quiz

Certified Professional Coder (CPC) Quiz: Apply Endocrine Coding Rules

Practice Apply Endocrine Coding Rules in Certified Professional Coder (CPC) with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Apply Endocrine Coding Rules, giving you a quick way to practice the rules, question types, and explanations that matter most for Certified Professional Coder (CPC).

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

A surgeon removes a pituitary adenoma via a transsphenoidal approach. In which CPT® code range are transsphenoidal pituitary surgery codes found?

  1. 61546-61548 (correct answer)
  2. 61500-61516
  3. 60600-60605
  4. 62165
Explanation: CPT® codes 61546-61548 cover transsphenoidal surgery for pituitary tumors. Code 61546 covers transsphenoidal excision of pituitary adenoma; 61548 covers hypophysectomy by transsphenoidal approach. The pituitary gland, although functionally part of the endocrine system, is surgically accessed via neurosurgical approaches and its procedure codes are found in the nervous system section (60000 series).

Question 2

A patient with type 1 diabetes is admitted for diabetic ketoacidosis (DKA) with coma. Which ICD-10-CM code is reported?

  1. E10.10
  2. E10.11 (correct answer)
  3. E11.01
  4. E13.00
Explanation: ICD-10-CM E10.11 covers type 1 diabetes mellitus with ketoacidosis with coma. E10.10 covers type 1 DKA without coma. E11.01 is type 2 diabetes with DKA with coma. ICD-10-CM provides combination codes that capture both the type of diabetes, the complication (DKA), and the presence or absence of coma — documentation of all three elements drives precise code selection.

Question 3

A patient with type 2 diabetes develops a diabetic foot ulcer on the plantar surface of the right foot with muscle involvement. Which ICD-10-CM code category is used for the diabetic foot ulcer?

  1. E11.621 (correct answer)
  2. E11.622
  3. E11.628
  4. L97.419
Explanation: ICD-10-CM E11.621 covers type 2 diabetes mellitus with foot ulcer. The additional code for the site and severity of the ulcer (L97.4-L97.5 series for foot ulcers) is also required. The diabetes combination code E11.621 captures both the diabetes and the foot ulcer manifestation; however, a separate L97 code is added per ICD-10-CM instructions to identify the site and severity.

Question 4

A patient's record documents that the patient uses insulin to manage type 2 diabetes. Which additional ICD-10-CM code is required?

  1. E11.649
  2. Z79.4 (correct answer)
  3. Z79.84
  4. Z96.41
Explanation: When a type 2 diabetic patient uses insulin, ICD-10-CM Z79.4 (long-term current use of insulin) must be reported as an additional code per the Official Guidelines. This code distinguishes insulin-dependent management from oral hypoglycemic management. Z79.84 covers long-term use of oral hypoglycemic drugs — it is not reported for insulin. Z96.41 relates to presence of insulin pump, not routine insulin use.

Question 5

A patient is newly diagnosed with Cushing's syndrome due to an adrenal cortical adenoma. After surgical adrenalectomy, the postoperative diagnosis confirms benign adrenal adenoma as the cause. Which ICD-10-CM code is reported for the Cushing's syndrome?

  1. E24.0
  2. E24.2
  3. E27.0
  4. E24.8 (correct answer)
Explanation: ICD-10-CM E24.0 covers pituitary-dependent Cushing's disease, which is ACTH-dependent and caused by a pituitary adenoma or hypothalamic disorder. An adrenal cortical adenoma produces cortisol autonomously (ACTH-independent), which is classified under E24.8 (Other Cushing's syndrome). E24.2 is drug-induced Cushing's syndrome. E27.0 covers other adrenocortical overactivity such as congenital adrenal hyperplasia — not autonomous cortisol excess from an adenoma.

Question 6

The documentation states: "The patient has no personal history of diabetes but has a strong family history of type 2 diabetes. Family history is the reason for today's diabetes screening." Which ICD-10-CM code is most appropriate as the first-listed diagnosis?

  1. E11.9
  2. Z83.3
  3. Z13.1 (correct answer)
  4. Z82.3
Explanation: Z13.1 covers encounter for screening for diabetes mellitus. When a patient presents specifically for diabetes screening due to risk factors (family history), the screening Z code is the first-listed diagnosis. Z83.3 is family history of diabetes and would be reported as an additional code. E11.9 is not appropriate since the patient has no confirmed diagnosis of diabetes.

Question 7

A patient with an established diagnosis of type 2 diabetes presents for a routine diabetes management visit. The physician adjusts the patient's metformin dosage. Which Z code is appropriate as an additional code for this encounter?

  1. Z79.4
  2. Z79.899
  3. Z87.39
  4. Z79.84 (correct answer)
Explanation: ICD-10-CM Z79.84 covers long-term (current) use of oral hypoglycemic drugs. When a type 2 diabetic patient is managed with oral agents such as metformin, Z79.84 is reported as an additional code per ICD-10-CM guidelines. Z79.4 is reserved for long-term insulin use. Accurately reporting the type of medication management distinguishes insulin-dependent from non-insulin-dependent treatment in the medical record.

Question 8

The operative report documents removal of a thyroglossal duct cyst including the central portion of the hyoid bone (Sistrunk procedure). Which CPT® code is reported?

  1. 60200
  2. 42820
  3. 60280 (correct answer)
  4. 60281
Explanation: CPT® 60280 covers excision of thyroglossal duct cyst or sinus. The Sistrunk procedure — which includes removal of the central portion of the hyoid bone to reduce recurrence — is the standard technique and is captured by 60280. Code 60281 is for recurrent thyroglossal duct cyst excision. Code 60200 covers excision of a thyroid cyst or adenoma, not a thyroglossal duct cyst.

Question 9

The ICD-10-CM Tabular List includes a "code first" note at E08 (diabetes mellitus due to underlying condition) directing the coder to code the underlying condition first. A patient has diabetes caused by Cushing's syndrome. Which sequencing is correct?

  1. E08 first, then the Cushing's syndrome code
  2. Cushing's syndrome (E24.9) first, then E08.9 (correct answer)
  3. Either order is acceptable for diabetes caused by an endocrine disorder
  4. Only E08 is reported — the underlying condition is captured by the combination code
Explanation: The "code first" instruction at ICD-10-CM category E08 requires the underlying condition causing the diabetes to be sequenced before the diabetes code. For diabetes caused by Cushing's syndrome, the Cushing's code (E24.9 or appropriate subcategory) is sequenced first, followed by E08.9 (or the appropriate E08 subcategory based on complications). This is mandatory sequencing per the etiology/manifestation convention.

Question 10

A surgeon performs a thyroidectomy and, during the same operative session, must surgically manage an inadvertently injured parathyroid gland by reimplanting it. Can the parathyroid reimplantation be reported separately?

  1. Yes — the add-on code 60512 for parathyroid autotransplantation is reported in addition to the thyroidectomy code (correct answer)
  2. No — any incidental parathyroid work is always bundled into the thyroidectomy
  3. Yes, with modifier -22 added to the thyroidectomy code to reflect the increased complexity
  4. Yes, with modifier -59 on the parathyroid code
Explanation: CPT® add-on code 60512 (parathyroid autotransplantation) is specifically designed to be reported in addition to the primary thyroid or parathyroid procedure when autotransplantation is performed. Since it is an add-on code, modifier -51 does not apply. The reimplantation is a separately identifiable service captured by 60512, not bundled into the primary thyroid procedure.

Question 11

A physician documents "brittle diabetes" for a type 1 diabetic patient. How is this documented condition coded in ICD-10-CM?

  1. E10.9 with modifier
  2. E10.649
  3. E10.9 — brittle diabetes is not a separately classified condition in ICD-10-CM (correct answer)
  4. E10.8
Explanation: ICD-10-CM does not have a specific code for "brittle diabetes." The condition is captured under the appropriate type 1 diabetes code based on the documented complications. Without a specific complication documented, E10.9 (type 1 diabetes mellitus without complications) would apply. "Brittle" is a clinical descriptor, not an ICD-10-CM axis. Coders should query the physician for any specific complications to code them correctly.

Question 12

A patient undergoes removal of the right thyroid lobe only (right thyroid lobectomy), leaving the left lobe intact. Which CPT® code is reported?

  1. 60210
  2. 60212
  3. 60220 (correct answer)
  4. 60240
Explanation: CPT® 60220 covers total thyroid lobectomy, unilateral, with or without isthmusectomy. This code represents removal of one complete lobe of the thyroid. Code 60210 is partial lobectomy; 60212 is partial lobectomy with contralateral subtotal lobectomy; 60240 is total thyroidectomy (both lobes).

Question 13

A surgeon performs a laparoscopic pancreatectomy (distal) for a functioning insulinoma of the pancreatic tail. For CPT® coding purposes, the endocrine-related pancreatic procedure is found in which section?

  1. Endocrine system (60000 series)
  2. Digestive system (40000 series) (correct answer)
  3. Urinary system (50000 series)
  4. Medicine section
Explanation: Despite the endocrine function of the pancreatic islet cells, CPT® classifies pancreatic surgical procedures under the digestive system (40000 series). Pancreatectomy codes (e.g., 48140 for distal pancreatectomy) are found in the digestive system section. The anatomical location and surgical access of the pancreas drives its CPT® classification, not its endocrine secretory function.

Question 14

A surgeon performs a total thyroidectomy for papillary thyroid carcinoma. The parathyroid glands are identified and preserved. Which CPT® code is reported for the thyroidectomy?

  1. 60240 (correct answer)
  2. 60220
  3. 60252
  4. 60254
Explanation: CPT® 60240 covers total thyroidectomy. Code 60220 covers partial thyroid lobectomy with or without isthmusectomy; 60252 covers total thyroidectomy for malignancy with limited neck dissection; 60254 covers total thyroidectomy for malignancy with radical neck dissection. Since no neck dissection is documented, 60240 is the correct code.

Question 15

A surgeon performs a reoperation for persistent hyperparathyroidism after a previous failed neck exploration. Which CPT® code is reported for the re-exploration?

  1. 60500
  2. 60502 (correct answer)
  3. 60505
  4. 60512
Explanation: CPT® 60502 covers re-exploration of parathyroid glands. This code is specifically used when a previous parathyroid exploration was performed and a second surgery is required due to persistent or recurrent hyperparathyroidism. Code 60500 is for initial exploration only. Using the correct re-exploration code accurately reflects the increased complexity of operating in a previously explored field.

Question 16

The operative report documents a laparoscopic right adrenalectomy for a benign adrenal adenoma. Which CPT® code is reported?

  1. 60540
  2. 60545
  3. 60650 (correct answer)
  4. 60659
Explanation: CPT® 60650 covers laparoscopic adrenalectomy, including exploration of the adrenal gland with or without biopsy, transabdominal, lumbar, or dorsal approach. Codes 60540 and 60545 cover open adrenalectomy (60540 without exploration; 60545 with excision of adjacent retroperitoneal tumor). The laparoscopic approach is specifically captured by 60650.

Question 17

A surgeon performs a total thyroidectomy for malignancy and also performs a limited (central compartment) neck dissection to address regional lymph node involvement. Which CPT® code is reported?

  1. 60240
  2. 60252 (correct answer)
  3. 60254
  4. 60260
Explanation: CPT® 60252 covers total thyroidectomy for malignancy with limited neck dissection. Code 60240 is total thyroidectomy without neck dissection; 60254 is total thyroidectomy for malignancy with radical neck dissection. The extent of the neck dissection (limited vs. radical) is the key differentiator within thyroid malignancy surgery codes.

Question 18

A patient is seen for management of hypothyroidism. The physician prescribes levothyroxine and orders a TSH level. Which ICD-10-CM code is reported for primary hypothyroidism, unspecified?

  1. E03.0
  2. E03.1
  3. E03.9 (correct answer)
  4. E06.3
Explanation: ICD-10-CM E03.9 covers hypothyroidism, unspecified. E03.0 is congenital hypothyroidism with diffuse goiter; E03.1 is congenital hypothyroidism without goiter; E06.3 is autoimmune thyroiditis (Hashimoto's). When the documentation states "hypothyroidism" without further specification of the type or etiology, E03.9 is the appropriate code.

Question 19

A patient with an adrenal cortical carcinoma undergoes open right adrenalectomy with en bloc resection of the adjacent retroperitoneal tumor extension. Which CPT® code is reported?

  1. 60540
  2. 60650
  3. 60659
  4. 60545 (correct answer)
Explanation: CPT® 60545 covers adrenalectomy with excision of adjacent retroperitoneal tumor. This code is used when the adrenalectomy involves en bloc removal of a retroperitoneal tumor extension beyond the adrenal gland itself. Code 60540 is adrenalectomy without this additional resection; 60650 is the laparoscopic approach; 60659 is laparoscopic with excision of adjacent retroperitoneal tumor.

Question 20

A patient is admitted with hyperosmolar hyperglycemic state (HHS) in the setting of type 2 diabetes. Which ICD-10-CM code is reported?

  1. E11.00 (correct answer)
  2. E11.01
  3. E11.649
  4. E11.65
Explanation: ICD-10-CM E11.00 covers type 2 diabetes mellitus with hyperosmolarity without nonketotic hyperglycemic-hyperosmolar coma (NKHHC). E11.01 covers type 2 DM with hyperosmolarity with coma. If the documentation does not specify coma, E11.00 is the appropriate code. If coma is present and documented, E11.01 is used. The presence or absence of coma is the key differentiator within the hyperosmolar subcategory.