1.3 COC vs CPC, CIC, and CASCC
Key Takeaways
- AAPC's COC credential page describes hospital outpatient and facility coding with ICD-10-CM, CPT, HCPCS Level II, APCs, and revenue-code linkage — not physician professional billing as the primary job.
- AAPC's CPC credential page describes outpatient and physician/professional services, typically billed on the CMS-1500.
- AAPC's CIC credential page describes inpatient ICD-10-CM plus ICD-10-PCS and MS-DRG work; the approved-books chart lists CIC as 40 multiple-choice items plus 7 fill-in inpatient cases, books 2 and 3.
- AAPC's CASCC page is an ASC specialty credential using the same three outpatient code sets; maintenance still needs 36 CEUs every two years, and AAPC requires 8 of those CEUs to be ASC-specific.
- CPC-H is the retired former name of today's COC (AAPC materials still identify CPC-H as now COC).
COC vs CPC, CIC, and CASCC
Quick Answer: Certified Outpatient Coder (COC) is the American Academy of Professional Coders (AAPC) credential for hospital outpatient and ambulatory surgery center (ASC) facility coding (CPT, ICD-10-CM, HCPCS Level II, OPPS/APC, revenue codes). Certified Professional Coder (CPC) is physician/professional coding. Certified Inpatient Coder (CIC) is inpatient ICD-10-CM plus ICD-10-PCS. Certified Ambulatory Surgery Center Coder (CASCC) is an ASC specialty. CPC-H is the retired former name of today's COC.
Why the alphabet soup is an exam issue
Job posts, recruiters, and even hospital human-resources templates mix these letters. A CPC who has never seen a UB-04, a revenue code, or an Ambulatory Payment Classification (APC) status indicator is not yet doing COC work. A CIC candidate who lives in ICD-10-PCS tables is not sitting the same open-CPT exam. If you study the wrong claim form, you will miss AAPC's 13 payment-methodology questions even if your CPT surgery is strong.
This independent OpenExamPrep guide helps learners study for AAPC's COC. It does not argue that OpenExamPrep replaces AAPC, and it does not treat the four credentials as interchangeable titles.
Four credentials, four jobs
Certified Outpatient Coder (COC)
AAPC's COC page describes expertise in coding outpatient hospital and facility services: same-day surgeries, emergency department (ED) visits, and hospital outpatient clinic services, using ICD-10-CM, Current Procedural Terminology (CPT), and Healthcare Common Procedure Coding System (HCPCS) Level II. AAPC also lists outpatient reimbursement including APCs, documentation and compliance (including National Correct Coding Initiative (NCCI) edits), and linking codes to revenue codes and APC assignment.
COC is the credential for hospital outpatient departments (HOPDs) and for facility-side ASC coding at core (not specialty) depth. Procedure coding is still CPT, not ICD-10-PCS. Payment thinking is Outpatient Prospective Payment System (OPPS) packaging and APCs, with enough Inpatient Prospective Payment System (IPPS) knowledge to tell outpatient from inpatient — AAPC puts OPPS and IPPS on the COC payment-methodology domain for that reason.
Certified Professional Coder (CPC)
AAPC's CPC page describes coding across outpatient and physician services, with ICD-10-CM, CPT, and HCPCS Level II, and a focus on professional services: office Evaluation and Management (E/M), procedures in physician practices and other outpatient settings, medical-necessity linkage, and professional modifiers. The professional claim form is the CMS-1500. AAPC presents CPC as a common starting credential. It is not the hospital facility outpatient credential.
Same CPT book, different reporting entity. For a laparoscopic cholecystectomy, the hospital bills a facility fee (revenue codes, OPPS, possibly an ASC payment if the site is an ASC). The surgeon bills a professional fee. COC tests the facility side, including packaging that professional billers do not live in every day. CPC tests the professional side, including global-period and office-E/M issues that facility coders handle differently.
Certified Inpatient Coder (CIC)
AAPC's CIC page describes inpatient hospital coding: ICD-10-CM diagnoses and International Classification of Diseases, Tenth Revision, Procedure Coding System (ICD-10-PCS) procedures, Medicare Severity Diagnosis-Related Group (MS-DRG) assignment, and inpatient documentation. AAPC's approved-code-books chart lists CIC as 40 multiple-choice questions plus 7 inpatient fill-in-the-blank cases, books 2 and 3 (ICD-10-CM and ICD-10-PCS). CPT and HCPCS Level II are not CIC's procedure code sets. Inpatient stays use IPPS/MS-DRG logic, not OPPS APCs, as the inpatient grouping engine.
If the patient is admitted as inpatient, the facility inpatient coder is in CIC territory. If the patient is discharged from same-day surgery, ED, or outpatient observation under outpatient rules, you are in COC territory. Observation versus admission is a documentation and status decision with coding consequences; it is also the fork between "still CPT/OPPS" and "now PCS/MS-DRG."
Certified Ambulatory Surgery Center Coder (CASCC)
AAPC's CASCC page describes a specialty credential for coding services in ambulatory surgery centers. The code sets overlap COC (ICD-10-CM, CPT, HCPCS Level II), with ASC-specific reporting, modifiers, bundling, and payment. AAPC's approved-code-books chart lists CASCC as a 100-question specialty exam with books 1, 2, 4. AAPC's exam-cost support page lists specialty exams at $325 for one attempt and $399 for two (confirm the price in your cart). Maintenance is still membership plus 36 continuing education units (CEUs) every two years, and AAPC requires 8 of those CEUs to be ASC-specific.
CASCC is depth in ASC. COC is the broader hospital-outpatient-plus-ASC facility core, including ED, observation, and hospital clinics that a pure ASC specialty exam is not built to be. AAPC's COC surgery domain is "procedures approved for outpatient hospital and ASC facilities" — COC already expects ASC-eligible procedure thinking, without being the CASCC specialty credential.
Side-by-side comparison
| Feature | COC | CPC | CIC | CASCC |
|---|---|---|---|---|
| AAPC type | Core | Core | Core | Specialty |
| Typical work | HOPD and ASC facility coding | Physician / professional coding | Hospital inpatient coding | ASC specialty coding |
| Procedure code set | CPT + HCPCS Level II | CPT + HCPCS Level II | ICD-10-PCS | CPT + HCPCS Level II |
| Diagnosis code set | ICD-10-CM | ICD-10-CM | ICD-10-CM | ICD-10-CM |
| Payment system to know | OPPS/APC, facility reporting | Professional fee, CMS-1500 | IPPS / MS-DRG | ASC payment and ASC facility rules |
| Claim-form emphasis | UB-04 (institutional); CMS-1500 appears as contrast | CMS-1500 | Institutional inpatient | ASC facility reporting |
| Approved books (AAPC chart) | 1, 2, 4 | 1, 2, 4 | 2, 3 | 1, 2, 4 |
| Exam shape (AAPC chart) | 100 multiple-choice | 100 multiple-choice | 40 multiple-choice + 7 fill-in cases | 100 multiple-choice |
| Former name | CPC-H (retired name of COC) | — | — | — |
CPC-H is not a second exam
Older job descriptions still say CPC-H (Certified Professional Coder — Hospital). AAPC retired that name. AAPC's support materials and anniversary writing identify CPC-H as now COC. If a posting requires CPC-H, read it as COC unless the employer truly wants inpatient CIC. Do not hunt for a CPC-H voucher that no longer exists under that name.
What COC is not — in language you can use on the exam
- Not CPC: You still need CPT skill, but facility packaging, revenue codes, UB-04 thinking, and OPPS status indicators are in scope. Professional global surgical package rules do not automatically apply to the facility claim.
- Not CIC: You do not construct ICD-10-PCS codes or assign MS-DRGs as your procedure methodology. You do need enough IPPS literacy to recognize when a case is inpatient, not outpatient.
- Not CASCC alone: COC includes ASC-approved procedures and ED, observation, and hospital clinics. Choosing CASCC instead of COC because "the hospital has an ASC" leaves the rest of the outpatient facility job untested.
AAPC's Taking the COC exam page states each exam measures only its named credential. Holding CPC does not skip COC domains. Holding COC does not skip CIC's PCS cases.
When a second credential is rational
- CPC then COC: a professional coder hired into HOPD or ASC facility coding who must learn OPPS, revenue codes, and facility modifiers (including discontinued-procedure 73/74 thinking).
- COC then CIC: an outpatient facility coder moving to inpatient coding or clinical documentation work who must add ICD-10-PCS and MS-DRG sequencing.
- COC then CASCC: a coder already facility-capable who now works in a high-volume ASC that wants specialty depth and will support the extra 8 ASC-specific CEUs.
Do not collect letters to look busy. Each exam is a separate AAPC fee (COC core pricing on the taking-the-exam page is $425 / $499; CASCC uses specialty pricing) and a separate CEU plan.
Candidate scenario: Priya's hospital offer
Priya is CPC-certified in a surgical specialty office. A hospital offers an outpatient facility coding seat: same-day surgery, hospital clinic, occasional ED overflow. The posting says "CPC or COC." Priya's CPT surgery is strong. She has never completed a UB-04, never applied a revenue code, and has not used OPPS status indicators.
If she treats COC as "another CPC with hospital in the title," she will under-study AAPC's 13 payment-methodology questions and the facility-modifier subset of the 22 surgery items (discontinued procedures, packaging versus separately paid, ASC versus HOPD). She buys current AMA CPT Professional, ICD-10-CM, and HCPCS Level II — the same 1, 2, 4 set she used for CPC — and rebuilds her notes around facility reporting. She does not add ICD-10-PCS; that is CIC. She does not skip COC in favor of CASCC; the job includes clinic and ED, which are COC's broader outpatient facility scope. After she passes, she will keep AAPC membership ($229 per year on 2026 membership pages) and 36 CEUs every two years — the same maintenance shell as CPC, now attached to the COC letters on her badge.
Official pages
Which AAPC credential is built around hospital inpatient ICD-10-CM and ICD-10-PCS coding rather than CPT facility outpatient coding?
What is CPC-H in current AAPC credential naming?
Which setting and payment pair best matches AAPC's published COC focus?