COC Exam Prep: Free Practice Questions, Section Map & 6-Week Plan

The AAPC Certified Outpatient Coder (COC) exam is 100 multiple-choice questions in 4 hours (AAPC COC certification FAQ). Start your COC exam prep with the op-note drill, then use the section map and 25 practice questions below.

Op-note drill: abstract before you code

Surgery and modifiers is the biggest section in AAPC's estimates. Code what the note documents. Read this original note, fill in the fields yourself, then compare.

Hospital outpatient procedure. Right knee arthroscopy. The torn portion of the medial meniscus was trimmed and removed. The lateral compartment was inspected; no treatment was performed there. No meniscal repair or open conversion occurred.

Op-note drill: what the fictional right knee arthroscopy note supports for each abstraction field
Field	What the note supports
Action	Removal of the torn portion of the medial meniscus
Anatomy and side	Medial meniscus, right knee
Approach	Arthroscopic
Extent	Partial removal; no meniscal repair documented
Only inspected	Lateral compartment, with no treatment
Don't code	An open procedure, a repair, or treatment in the lateral compartment

Now find the arthroscopic knee and meniscus procedures in your CPT book. Read the full descriptors and the section notes, and decide which details above choose between them. Then check for any modifier or National Correct Coding Initiative (NCCI) edit questions. The point of the drill is the reading, so do it with your own book.

Your prep in four moves

Set up your references. AMA CPT Professional Edition, an ICD-10-CM book, and a HCPCS Level II book, all current-year if you can. Decide now whether you will test with printed books or the exam's built-in eBooks; you can't use both.
Study by section weight. Surgery and modifiers, ICD-10-CM, payment methodologies, and CPT make up an estimated 63 of the 100 questions.
Learn the facility rules, not just the codes. The Outpatient Prospective Payment System (OPPS), Ambulatory Payment Classifications (APCs), status indicators, facility modifiers, and Advance Beneficiary Notices (ABNs). This is what separates the COC from physician-side coding.
Practice under the clock. You have about 2.4 minutes per question, and the last 10 questions are full medical-record cases.

Where the 100 COC questions come from

AAPC publishes estimated question counts for each section (2026 Official COC Study Guide sample, pp. 3–4). Sorted from most to fewest:

COC exam section map: AAPC estimated question counts, what each section tests and how to study it
Section	Questions (AAPC estimate)	What it tests in practice	How to study it
Surgery and modifiers	22	Outpatient hospital and ambulatory surgery center (ASC) procedures, plus facility modifier use	Abstract op notes before coding; drill modifiers 73, 74, 52, PT, and NCCI edits
ICD-10-CM	15	Diagnosis selection under outpatient rules	Read Section IV of the Official Guidelines; practice conventions (Excludes1, "with," 7th characters)
Payment methodologies	13	OPPS, APCs, payment status indicators, ASC payment, Medicare Severity Diagnosis Related Group (MS-DRG) basics	Learn what each common status indicator does to payment
CPT	13	Guideline-driven code selection	Read section guidelines in your CPT book; practice size and length math
Cases	10 (1 question each)	Coding a full record with CPT, ICD-10-CM, and HCPCS Level II	Timed record coding; these come at the end of the exam
Medical terminology	7	Terms across all body systems	Roots, prefixes, surgical suffixes
Anatomy	7	Anatomy across all body systems	Pair it with the procedures you code most
HCPCS Level II	7	Supplies, drugs, G-codes, HCPCS modifiers	Drug units, JW/JZ, hospital G-codes
Coding guidelines	3	Official coding rules across code sets	Folds into your ICD-10-CM and CPT study
Compliance	3	National/local coverage determinations (NCDs/LCDs), the Health Insurance Portability and Accountability Act (HIPAA), ABNs	ABN modifiers GA, GZ, GX, GY; coding only what's documented

These are AAPC's estimates, not fixed quotas, and AAPC notes that diagnosis questions also show up inside the CPT-category sections (Taking the COC exam). So ICD-10-CM skill counts for more than its 15 dedicated questions.

Free COC practice questions (25, with rationales)

These 25 questions are original and unofficial, written by Castleport Test Prep. They are not actual or recalled AAPC exam items, and they are not a full-length exam. They sample every AAPC section and use 2026 exam-study references; confirm codes in the references you'll test with. Your score here is feedback on these items, not a prediction of your exam result.

Question 1 — Medical terminology

A surgeon brings a segment of the colon through the abdominal wall to create a permanent opening for stool to exit. Which term describes this procedure?

A. Colectomy
B. Colotomy
C. Colostomy
D. Coloplasty

Show answer and explanation

Answer: C. Colostomy. The suffix -ostomy means surgically creating an opening. -ectomy is removal (a colectomy removes part of the colon), -otomy is an incision into the organ, and -plasty is surgical repair (MedlinePlus, word parts: procedures and surgery). On an op note, the suffix tells you which family of procedures to look in. It doesn't pick the code for you.

Question 2 — Medical terminology

An operative note reads: "An incision was made into the stomach, the foreign body was retrieved, and the stomach was closed." Which suffix describes the main procedure?

A. -ectomy
B. -otomy
C. -ostomy
D. -plasty

Show answer and explanation

Answer: B. -otomy (gastrotomy). -otomy means an incision into an organ (MedlinePlus, word parts: procedures and surgery). The surgeon cut into the stomach and closed it. No stomach tissue was removed, and no permanent opening was made. Picking -ectomy would send you to a resection code, and -ostomy to a code for creating a stoma. Both overstate what happened. Closing the access incision does not make the main procedure a -plasty.

Question 3 — Anatomy

Which segment of the small intestine attaches to the stomach at the pyloric sphincter?

A. Duodenum
B. Jejunum
C. Ileum
D. Cecum

Show answer and explanation

Answer: A. Duodenum. The small intestine runs duodenum, then jejunum, then ileum. The duodenum is the short first segment (about 25 cm), joined to the stomach at the pylorus (NCI SEER Training). The cecum isn't small intestine at all. It's the start of the large intestine.

Question 4 — Anatomy

A colonoscopy report describes a lesion at the ileocecal valve. Which two structures does this valve separate?

A. Stomach and duodenum
B. Jejunum and ileum
C. Sigmoid colon and rectum
D. Ileum and cecum

Show answer and explanation

Answer: D. Ileum and cecum. The ileocecal valve is where the small intestine ends and the large intestine begins (NCI SEER Training). That tells you a lesion "at the valve" is reached by colonoscopy, not by upper endoscopy (NIDDK, endoscopy procedures).

Question 5 — Coding guidelines

A patient is seen in a hospital outpatient clinic for right lower quadrant abdominal pain. All test results are back. The provider's final assessment reads "right lower quadrant pain; possible appendicitis." No definitive diagnosis is documented. Which diagnosis code is correct?

A. R10.31
B. R10.30
C. R10.32
D. K35.80

Show answer and explanation

Answer: A. R10.31 (right lower quadrant pain). In outpatient settings, don't code a diagnosis documented as possible, probable, suspected, or rule out. Code the condition to the highest degree of certainty for that encounter, which here is the symptom (ICD-10-CM Official Guidelines FY2026, §IV.H; §I.B.4 allows symptom codes when no definitive diagnosis is established). Look it up as Pain → abdominal → lower → right quadrant, then confirm in the Tabular List. B drops the documented location, C is the wrong side, and D (unspecified acute appendicitis) codes a condition that was never confirmed.

Question 6 — Payment methodologies

On a Medicare hospital outpatient claim, a HCPCS code carries OPPS payment status indicator N. What does that mean for payment?

A. Packaged into the payment for other services, with no separate APC payment
B. Paid separately, subject to multiple-procedure discounting
C. Not covered under any Medicare outpatient benefit
D. Inpatient-only; not payable under OPPS

Show answer and explanation

Answer: A. Status indicator N means the item or service is packaged into the APC payment for other services on the claim (Noridian, OPPS payment status indicators). Report the service as required; packaging means it does not earn a separate payment. B describes status indicator T, C describes E1, and D describes C.

Question 7 — Payment methodologies

Medicare pays most hospital outpatient department services under the Outpatient Prospective Payment System (OPPS). Services are grouped into which classification for payment?

A. MS-DRGs
B. Physician fee schedule relative value units
C. Revenue codes
D. Ambulatory Payment Classifications (APCs)

Show answer and explanation

Answer: D. APCs. OPPS assigns HCPCS codes to APCs, and the APC sets the base payment. MS-DRGs are how CMS pays acute care hospital inpatient stays (CMS, Medicare Payment Systems). The physician fee schedule pays the professional's service, not the facility's. Revenue codes identify the department or type of charge on the facility claim, but they don't set the OPPS rate (CMS, institutional claims).

Question 8 — Payment methodologies

A Medicare patient has a procedure performed as a hospital outpatient. The procedure's OPPS status indicator is C, and no exception to the inpatient-only policy applies. How is the procedure treated under OPPS?

A. It is paid under OPPS through a separate APC payment
B. It is packaged into the clinic visit payment
C. It is not paid under OPPS under these circumstances; it has an inpatient-only designation
D. It is paid through a comprehensive APC with eligible associated services packaged

Show answer and explanation

Answer: C. Status indicator C marks inpatient-only procedures. Under the stated circumstances, the procedure is not paid under OPPS (CMS Pub. 100-04, Ch. 4, §180.7). The indicator is not an admission order or permission to change the documented patient status. That's why facilities check status indicators before scheduling a procedure as outpatient, not after. D describes status indicator J1 (Noridian).

Question 9 — Payment methodologies

A freestanding, Medicare-certified ambulatory surgery center (ASC) performs a covered procedure. How does Medicare pay the ASC's facility service?

A. Through an inpatient MS-DRG
B. Through the ASC payment system, generally a single payment for each covered procedure
C. Through hospital OPPS, because every outpatient surgery is paid under OPPS
D. Through the physician fee schedule, because a surgeon performed the procedure

Show answer and explanation

Answer: B. Medicare pays ASCs under their own payment system, generally a single payment per covered procedure that includes nursing, facility use, and most supplies. Most ASC rates are built from OPPS APC relative weights, but the ASC system is separate from hospital OPPS (CMS, Medicare Payment Systems). A is an inpatient payment, C wrongly treats every outpatient setting as a hospital department, and D confuses the surgeon's professional payment with the facility's.

Question 10 — Payment methodologies

A Medicare patient receives observation services overnight in the hospital and goes home the next morning. No inpatient admission order was written. What is the patient's status for this stay?

A. Inpatient, because the stay crossed midnight
B. Inpatient, because the patient used a hospital bed
C. Whichever status pays the hospital more
D. Outpatient

Show answer and explanation

Answer: D. Outpatient. Observation services are outpatient care, even when the patient spends the night. A patient becomes an inpatient only when formally admitted with a doctor's order (Medicare.gov, inpatient or outpatient status). A and B swap the admission order for time or location, and C swaps it for payment. The coder reports the documented status; deciding whether admission was appropriate isn't the coder's call.

Question 11 — Compliance

An Original Medicare beneficiary gets a lab test in a hospital outpatient department. The hospital expected Medicare to deny it as not reasonable and necessary because it exceeds the covered frequency, so staff issued a valid, required Advance Beneficiary Notice (ABN) before the test. The patient signed it, and it's on file. Which modifier applies?

A. GA
B. GZ
C. GX
D. GY

Show answer and explanation

Answer: A. GA. GA reports that a required ABN was issued and is on file. GZ is for an expected medical-necessity denial when no ABN was issued. GX is for a voluntary ABN for a service Medicare never covers. GY is for a statutorily excluded service or one that is not a Medicare benefit; a mandatory ABN is not required (CMS, Medicare Advance Written Notices of Non-coverage, pp. 5–7 and 11).

Question 12 — Compliance

A supervisor asks a coder to assign a higher-level, better-paying service code to help the department meet a revenue target. The record supports only the lower-level service. What should determine the code?

A. The revenue target
B. The highest service that might have been performed
C. The documented services and the applicable coding rules
D. The patient's ability to pay

Show answer and explanation

Answer: C. Claims must be supported by documentation. Billing a higher-level service than was provided or documented is upcoding (HHS-OIG, physician relationships with payers). A and D let money drive the code, and B invents a service the record doesn't show.

Question 13 — ICD-10-CM

The provider documents type 2 diabetes mellitus and chronic kidney disease, stage 3a. The note doesn't say whether the diabetes caused the CKD. Which codes are correct?

A. E11.9, N18.31
B. E11.22 only
C. E11.22, N18.31
D. N18.31, E11.9

Show answer and explanation

Answer: C. E11.22 (type 2 diabetes with diabetic CKD) and N18.31 (CKD stage 3a). ICD-10-CM presumes a cause-and-effect link between conditions joined by "with" in the Alphabetic Index or Tabular List, unless the documentation clearly says they're unrelated (Official Guidelines FY2026, §I.A.15). Diabetes "with" chronic kidney disease indexes to E11.22, and that code tells you to add a code for the CKD stage (2026 ICD-10-CM Index and Tabular List). A and D ignore the presumed link. B leaves out the required stage code.

Question 14 — ICD-10-CM

A patient returns to the hospital's orthopedic clinic for cast removal. The closed traumatic distal radius fracture is healing normally after treatment six weeks ago. Which 7th character goes on the fracture code?

A. D (subsequent encounter)
B. A (initial encounter)
C. S (sequela)
D. No 7th character is needed for an aftercare visit

Show answer and explanation

Answer: A. Seventh character D. For this closed fracture, D identifies subsequent care with routine healing, such as cast changes or removal and follow-up visits (Official Guidelines FY2026, §I.C.19.a and §I.C.19.c; 2026 Tabular List, S52). Seventh character A is for encounters during active treatment. Seventh character S is for a complication or condition that results from the injury, such as a scar. This traumatic fracture code requires a 7th character, so leaving it off isn't an option.

Question 15 — ICD-10-CM

The Tabular List shows an Excludes1 note under the code for Condition X, and the note lists Condition Y. The provider documents both conditions and clearly states they are unrelated to each other. What should you do?

A. Never report both codes together
B. Report only Condition Y
C. Report only the condition listed first in the Tabular List
D. Report both codes, because the conditions are documented as unrelated

Show answer and explanation

Answer: D. An Excludes1 note normally means the two codes are never reported together. The official exception: when the two conditions are unrelated, both may be reported. If you can't tell whether they're related, query the provider (Official Guidelines FY2026, §I.A.12.a). A is the default rule without the exception, and the exception is exactly what this question tests. B and C would omit one of the unrelated documented conditions without a reason.

Question 16 — CPT

A benign skin lesion on the back, not a skin tag, has a greatest clinical diameter of 0.9 cm. The surgeon performs a full-thickness excision through the dermis with 0.3 cm margins on each side and closes it simply. Which excision code applies?

A. 11401
B. 11402
C. 11403
D. 11602

Show answer and explanation

Answer: B. 11402. Include the documented margin on each side: 0.9 + 0.3 + 0.3 = 1.5 cm. Code 11402 covers benign lesions of the trunk, arms, or legs with an excised diameter of 1.1 to 2.0 cm (CMS, October 2026 code file). A is the trap: coding the lesion alone (0.9 cm) drops you into the smaller size range. C is the next larger range. D is in the malignant-lesion series, but this lesion is benign. Use the lesion-plus-margin diameter.

Question 17 — CPT

In the emergency department, a patient gets simple repairs with sutures of a 2.5 cm scalp laceration and a 3.0 cm forearm laceration. How is the repair reported?

A. 12001 for each wound
B. 12002
C. 12001 and 12002
D. 12004

Show answer and explanation

Answer: B. 12002. Add together the lengths of wounds that have the same repair complexity and fall in the same anatomic group. The scalp and the extremities are both in the 12001–12007 group, and both repairs are simple, so the total is 5.5 cm. That falls in the 12002 range of 2.6 to 7.5 cm (ACEP, wound repair FAQ; CMS, October 2026 code file). A and C split up wounds that have to be added together. D is for a longer total. Wounds in different anatomic groups, or of different complexity, are reported separately.

Question 18 — HCPCS Level II

A Medicare patient has an evaluation and management visit in an on-campus hospital outpatient clinic. Which code does the hospital report for the clinic visit under OPPS?

A. 99213
B. 99283
C. 99213 with modifier 25
D. G0463

Show answer and explanation

Answer: D. G0463. Since January 1, 2014, CMS has recognized HCPCS G0463 for hospital outpatient clinic visits under OPPS. CPT 99201–99205 and 99211–99215 are no longer recognized for OPPS payment (CMS Transmittal 2845, §I.B.4; CMS E/M Services, May 2026, p. 13). A and C are the physician-side office visit codes. B is an emergency department visit level, not a clinic visit.

Question 19 — HCPCS Level II

A hospital outpatient department gives a separately payable, non-vaccine Part B drug from a single-dose vial. The patient receives the entire contents and nothing is discarded. Which modifier goes on the drug line?

A. JW
B. JZ
C. No modifier
D. KX

Show answer and explanation

Answer: B. JZ. JZ attests that none of a single-dose container drug was discarded. CMS has required it since July 1, 2023, when there's no waste on a separately payable single-dose container drug subject to this policy (CMS JW/JZ FAQs, Q2, Q5, and Q7). JW reports the amount discarded. Leaving the modifier off is wrong for these drugs. KX does not report zero discarded drug. JZ doesn't apply to multiple-dose containers.

Question 20 — HCPCS Level II

In a practice exercise, a drug's HCPCS code descriptor sets one billing unit at 10 mg. The record documents 50 mg administered, with nothing discarded. How many units represent the administered amount?

A. 50
B. 10
C. 5
D. 1

Show answer and explanation

Answer: C. 5 units. The dose description in the HCPCS descriptor defines how much product one billing unit represents (CMS HCPCS drug coding manual, §4.2). So 50 mg ÷ 10 mg per unit = 5 units. A counts milligrams as units, B repeats the amount per unit, and D assumes one administration equals one unit. The numbers here are made up for practice. This is billing arithmetic, not dosing advice.

Question 21 — Surgery and modifiers

A Medicare hospital outpatient is prepped and taken to the procedure room for a colonoscopy with anesthesia planned. Before any anesthesia or scope insertion, the patient's blood pressure spikes and the physician cancels the procedure. Which modifier does the hospital append?

A. 52
B. 53
C. 73
D. 74

Show answer and explanation

Answer: C. 73. On a hospital outpatient claim, modifier 73 reports a procedure with anesthesia planned that was stopped after the patient was prepared and taken to the room, but before anesthesia was given (CMS Pub. 100-04, Ch. 4, §20.6.4). D is for after anesthesia is given or the procedure has started. A is for reduced or discontinued services for which anesthesia was not planned. B is the physician-side discontinued-procedure modifier; CMS directs OPPS hospitals to 73, 74, or 52 instead.

Question 22 — Surgery and modifiers

General anesthesia is induced for a planned Medicare outpatient hospital procedure. Before the incision, a change in the patient's condition threatens their well-being and the physician stops the procedure. Which modifier does the hospital append?

A. 74
B. 52
C. 73
D. PT

Show answer and explanation

Answer: A. 74. Anesthesia had already been given, so this is a discontinuation after anesthesia (CMS Pub. 100-04, Ch. 4, §20.6.4). C applies before anesthesia is given and before the procedure starts. B is for services for which anesthesia was not planned. D signals a Medicare colorectal screening that became diagnostic or therapeutic. It has nothing to do with this. In this case, anesthesia had already been given. In other discontinued-procedure cases, also check whether the procedure had started.

Question 23 — Surgery and modifiers

A Medicare hospital outpatient CT scan is stopped partway through. No anesthesia was planned, and no separate HCPCS code describes the portion completed. Which modifier goes on the intended procedure code?

A. 52
B. 53
C. 73
D. 74

Show answer and explanation

Answer: A. 52. First code the radiology service actually completed. When no HCPCS code describes that portion, CMS directs the hospital to report the intended procedure code with modifier 52 (CMS Pub. 100-04, Ch. 4, §20.6.6 and §20.6.4). B is the physician-side discontinued-procedure modifier. C and D concern procedures with anesthesia planned or provided; no anesthesia was planned here. The answer depends on both facts in the stem, not on a blanket rule that radiology always takes 52.

Question 24 — Surgery and modifiers

Two procedures on a Medicare outpatient claim hit an active NCCI procedure-to-procedure edit with a modifier indicator of 1. Nothing in the record shows a separate encounter, a separate anatomic site, or another distinct-service circumstance. What's the right conclusion?

A. Modifier 59 should always be added when the indicator is 1
B. Indicator 1 allows a modifier only when the circumstances justify it, and the record here doesn't
C. Change one procedure to an unlisted code to avoid the edit
D. Split the services onto separate claims to avoid the edit

Show answer and explanation

Answer: B. An NCCI modifier indicator of 1 means a modifier may bypass the edit, but only in appropriate circumstances, such as separate encounters, anatomic sites, or specimens (CMS NCCI FAQ library). The indicator doesn't supply the justification; the record has to. A turns the exception into a habit. C and D dodge the edit instead of coding correctly.

Question 25 — Cases

Record summary: Asymptomatic Medicare patient, average risk, scheduled for a screening colonoscopy in the hospital outpatient department. The colonoscopy is completed. One sigmoid colon polyp is found and removed with a snare. No other procedures.

Which reporting is correct for the hospital?

A. G0121; Z12.11
B. 45385-PT; the polyp code first-listed, followed by Z12.11
C. 45378-PT; Z12.11
D. 45385-PT; Z12.11 first-listed, followed by the code for the polyp

Show answer and explanation

Answer: D. When a Medicare screening colonoscopy becomes therapeutic, report the procedure actually performed (45385, colonoscopy with removal by snare technique; 2026 NCCI Manual, Ch. VI, §H.25). Append modifier PT to show the service began as colorectal cancer screening; the deductible is waived (CMS Pub. 100-04, Ch. 18, §60.1.1 and §60.2). When screening was the reason for the encounter, the screening code (Z12.11) is listed first and the finding follows (Official Guidelines FY2026, §I.C.21.c.5). A reports only the screening and ignores the polypectomy. B reverses the diagnosis order. C is a colonoscopy without lesion removal.

Answer key: 1 C · 2 B · 3 A · 4 D · 5 A · 6 A · 7 D · 8 C · 9 B · 10 D · 11 A · 12 C · 13 C · 14 A · 15 D · 16 B · 17 B · 18 D · 19 B · 20 C · 21 C · 22 A · 23 A · 24 B · 25 D

Turn your misses into your next study task

Count how many you got right out of 25, but spend more time on why you missed. A miss you can name tells you what to study next. Review a lucky guess or a slow answer even if it was correct.

Missed practice questions routed to the usual problem and what to study next
If you missed…	Usually the problem is…	Study next
1–4	Reading the procedure or the anatomy	Word parts and anatomy for the body systems you code most; then the op-note drill above
5, 13–15	Outpatient diagnosis rules or ICD-10-CM conventions	Official Guidelines §I.A–I.B and Section IV; always confirm Index results in the Tabular List
6–10	Facility payment	Status indicators C, E1, J1, N, Q1, S, T, V; OPPS vs. ASC payment; inpatient vs. outpatient status
11–12, 24	Compliance and correct coding	ABN modifiers; NCCI modifier indicators; code only what's documented
16–17	CPT measurement rules	Lesion excision and wound-repair guidelines in your CPT book
18–20	HCPCS Level II	Hospital G-codes, JW/JZ, units per descriptor
21–23, 25	Facility modifiers and screening rules	Modifiers 52, 73, 74, and PT; screening Z codes

Keep a simple error log, in a notebook rather than in your code books (AAPC doesn't allow notes from practice exams in exam books):

Error log template with one example row
Question	Section	My answer	Why the right answer is right	Rule I missed and where it is	Recheck on
24	Surgery and modifiers	A	Indicator 1 allows a modifier only when the record supports it	NCCI modifier indicators (CMS NCCI FAQ)	(date)

Your 6-week COC study plan

This plan assumes you already know basic coding, from a CPC, coding coursework, or on-the-job experience. Budget five sessions a week of about 75 minutes (6 hours 15 minutes a week). It's an editorial plan, not an AAPC requirement or a guarantee; stretch it if a skill still needs work.

Six-week COC study plan by week: focus, tasks and what to keep in your log
Week	Focus	Do this	Keep in your log
1	References, terminology, anatomy	Confirm your book editions and pick print or eBook. Read ICD-10-CM §I.A–I.B and Section IV, and the CPT surgery guidelines. Review word parts and the anatomy of the systems you code most. Take questions 1–4.	Your reference choice; five-term and five-structure lists
2	ICD-10-CM (15 questions, plus diagnoses inside other sections)	Practice outpatient diagnosis selection: uncertain diagnoses, signs and symptoms, "with," Excludes1, 7th characters, screening Z codes. Take questions 5 and 13–15.	Each miss with the guideline section that fixes it
3	Payment methodologies and compliance (16 questions)	Learn OPPS and APC basics; status indicators C, E1, J1, N, Q1, S, T, V; ASC payment; observation status. Learn ABN modifiers and what NCDs and LCDs do. Take questions 6–12.	A one-line definition for each status indicator
4	Surgery and modifiers (22 questions)	Code from operative notes across body systems. Do the op-note drill. Drill modifiers 52, 73, 74, and PT, NCCI indicators, and size and length rules. Take questions 16–17 and 21–25.	The fact in each note that decided the modifier
5	CPT, HCPCS Level II, and cases (30 questions)	Section guidelines in CPT; drugs, supplies, units, JW/JZ, G0463. Code full records against the clock. Take questions 18–20.	Slowest lookups and how you'll speed them up
6	Timed practice and review	If you already have a lawful full-length practice set, schedule one uninterrupted 4-hour block for its 100 questions using your chosen references, replacing that week's shorter sessions as needed. Otherwise, work these 25 questions in 60 minutes, then repeat the op-note drill and review your two weakest topics. Review every miss by section. When retaking these questions, explain each answer; remembering familiar items is not fresh readiness evidence.	Three named tasks for any remaining gaps

The 25-question option gives you a timed review on this page; it does not test four-hour endurance.

Adjust the plan to your situation

Still building foundations: If terminology or finding codes is slowing you down, repeat Week 1 before moving on. Spreading the plan over 12 weeks is reasonable.
Coming from CPC study: Terminology, anatomy, and lookup skills carry over. Put your extra time into Weeks 3 and 4: facility payment, status indicators, and facility modifiers. Don't skip the other sections.
Retaking: Start from the areas your AAPC result flagged (AAPC exam results) and your own error log. A weak section and a slow lookup are different problems, and they need different fixes.
Exam date is close: Work your most frequent error type first, then the heaviest sections you haven't reviewed. Still do the reference check below.

How to manage 4 hours and 100 questions

AAPC's own math is about 2.4 minutes per question (Taking the COC exam). Two habits help:

Bank time for the cases. The last 10 questions are full medical-record cases. Keep moving through the first 90 so you aren't coding a full record in your final minutes.
Answer everything. AAPC advises answering every question, even when you're unsure. Flag hard ones and come back rather than stalling.

If you have a full-length practice set, use it for at least one uninterrupted timed sitting before test day. For a shorter timing exercise on this page, allow 60 minutes for the 25 questions.

Code books and exam-day references

Allowed references: AMA CPT Professional Edition (no other CPT publisher), any publisher's ICD-10-CM, and any publisher's HCPCS Level II (AAPC COC certification FAQ). Study guides aren't allowed, not even AAPC's own.
Print or eBook, not both: You choose printed books or the exam platform's eBooks for a given exam. The eBooks are searchable but standardized; your personal notes and highlights aren't in them (AAPC: eBooks vs. printed books).
Edition year: AAPC generally updates exams each January for that year's code sets; its 2026 HCPCS Level II transition was March 2. For printed references, you may use the current year's books, the preceding year's, or a mix, with one copy of each. Older books and next year's books aren't allowed. Current-year books are strongly recommended (AAPC: which year's books).
Two different calendars: The annual ICD-10-CM release used for actual patient care takes effect October 1; interim updates can also apply (CDC/NCHS release files). Your exam follows AAPC's exam-year policy, so an exam in November or December 2026 still uses 2026 code sets. If your appointment is in 2027, check AAPC's year-specific instructions before choosing references. These practice questions use 2026 exam-study references, not the code edition for every future date of service.
Notes and tabs in printed books: Tabs are for navigation only and can't add information. Brief handwritten notes and highlighting are allowed only if they relate to daily coding work. Nothing from study guides or practice exams is allowed, and neither are sticky notes, loose pages, or inserts (AAPC: what notes are allowed).

In the final week: confirm your appointment and which exam and year it's for, check your book editions or eBook choice, check your AAPC membership status, and if you test online, set up your room and equipment ahead of time.

COC exam facts at a glance

COC exam facts at a glance: detail for each exam item
Item	Detail
Credential owner	AAPC
Questions	100 multiple choice, including 10 single-question cases
Time	4 hours, one sitting
To pass	70 correct (70%)
Where	Online with a live remote proctor, or at a testing center; AAPC schedules through its testing partner, Meazure Learning
Cost	$499 for a voucher with two attempts
Membership	Your AAPC membership must be active when results are released, or AAPC holds them until you renew
Experience	Without proof of two years of coding experience (or the equivalent), passing earns the COC-A (apprentice) designation

Sources: AAPC COC certification FAQ, AAPC exam cost, Meazure Learning scheduling, membership and results, After the COC exam: apprenticeship.

For booking, results, and retakes, see AAPC exam registration, AAPC exam results, and the AAPC exam retake policy. To keep the credential after you pass, see AAPC certification renewal.

Common questions

Is the COC harder than the CPC? The two test different work. The COC is outpatient facility coding: hospital outpatient departments and ASCs, with OPPS, APCs, and status indicators. The CPC covers professional (provider-side) coding. If you come from CPC study, expect the payment-methodology and facility-modifier questions to feel least familiar, and give them extra time. See also CPC exam prep and the overview of medical billing and coding certifications.

Do I need to know MS-DRGs for an outpatient exam? AAPC lists MS-DRG knowledge as part of the COC credential (AAPC COC certification FAQ). Know what they are (the inpatient payment classification) and how they differ from APCs. The COC focuses on outpatient facility coding.

Can I take the COC if I'm already a CPC? Yes, they're separate AAPC credentials. Focus your prep on what's new to you: OPPS and APCs, status indicators, facility modifiers, and hospital HCPCS coding.

Sources and verification

By Castleport Test Prep Editorial Team. Last verified October 21, 2026: we checked the COC exam format, AAPC's estimated section counts, book-year, eBook, and notes policies, the exam fee, and the membership rule against AAPC's published pages. We checked the coding and payment rules in the practice questions against the CMS, CDC/NCHS, Medicare contractor, and other sources linked beside each answer. This was source and editorial checking, not review by a credentialed coder, and we did not test AAPC's booking or exam platform. AI tools assisted with research, drafting, and source checks; see our editorial standards.

AAPC: COC certification FAQ · Taking the COC exam · After the COC exam: apprenticeship · Apprenticeship equivalents · 2026 Official COC Study Guide sample pages
AAPC Support: Which year's books · Code books needed · eBooks vs. printed books · Notes allowed in exam books · Exam cost · Membership and results · Scheduling with Meazure Learning
CDC/NCHS and CMS: FY2026 ICD-10-CM Official Guidelines · 2026 Index and Tabular List ZIP · Release dates and files
CMS: Claims Processing Manual, Chapter 4 · Chapter 18: preventive services · Medicare Payment Systems · Institutional claims · ABN guidance · E/M Services, May 2026 · G0463 historical effective date · JW/JZ modifier FAQs · HCPCS drug coding manual · NCCI FAQ library · 2026 NCCI Manual, Chapter VI · October 2026 code file
Medicare and contractors: Medicare.gov inpatient or outpatient status · Noridian OPPS status indicators
Other: HHS-OIG physician education · ACEP wound repair FAQ · NCI SEER Training · NIDDK endoscopy procedures · MedlinePlus word parts

Castleport Test Prep is an independent exam prep publisher, not affiliated with, endorsed by, or approved by AAPC. Exam and credential names identify their subjects; CPT and other trademarks belong to their respective owners. The practice questions on this page are original and unofficial, not actual or recalled exam questions. No study resource guarantees passing, certification, employment, or payment of a claim.