Work through these ten groups in order, because later application assumes earlier foundations. Keep your ICD-10-CM, CPT, and HCPCS Level II code books open beside each concept, since rules are taught as decisions you will make on encounter and operative note documentation. Each concept pairs a rule with a resolved example and a common error to avoid. This guide is an independent study aid, not an official syllabus, and it does not replace official materials or hands-on coding experience.
ICD-10-CM Conventions and Structure
1. Index-First Workflow for Code Assignment
Always locate the documented condition in the Alphabetic Index first, then verify the code in the Tabular List while reading all instructional notes. The conventions and instructions of the classification itself take precedence over the guidelines that accompany it.
Example: A note documents heart failure; the coder locates the index entry, verifies the code in the Tabular List, and applies its instructional notes before finalizing the assignment.
Mistake to avoid: Assigning a code straight from the Tabular List without first locating the term in the Alphabetic Index.
Reference: CDC ICD-10-CM Official Guidelines, FY 2027
2. Placeholder X and Seventh Characters
Codes with applicable 7th characters are invalid without them, and the 7th character must always occupy the seventh position. When a code requiring a 7th character is shorter than six characters, fill the empty positions with the placeholder X.
Example: A five-character code that carries an applicable extension gets the placeholder inserted before the extension, making the completed code valid for reporting.
Mistake to avoid: Appending a 7th character directly to a short code without inserting the required X placeholders.
Reference: CDC ICD-10-CM Official Guidelines, FY 2027
3. Excludes1 Versus Excludes2 Notes
An Excludes1 note means the excluded code is never used with the code above it because the conditions cannot coexist, such as congenital versus acquired forms. An Excludes2 note means the excluded condition is not part of the code but both may be reported together when present.
Example: A patient has two conditions connected by an Excludes2 note under one of them; both are coded because the note permits the conditions to coexist.
Mistake to avoid: Treating every Excludes note as a prohibition and dropping a legitimately coexisting condition.
Reference: CDC ICD-10-CM Official Guidelines, FY 2027
4. NEC Versus NOS Abbreviations
NEC, meaning not elsewhere classifiable, directs the coder to an other specified code when no specific code exists for the documented condition. NOS, meaning not otherwise specified, is the equivalent of unspecified and is used when documentation lacks the detail for something better.
Example: A rare documented rhythm abnormality without its own code is assigned the other specified code, because the provider's documentation names the condition.
Mistake to avoid: Defaulting to an unspecified code when the documentation clearly supports an other specified code.
Reference: CDC ICD-10-CM Official Guidelines, FY 2027
5. The With Convention Presumes Linkage
The word with or in, when it appears in a code title, index entry, or instructional note, means associated with or due to, and the classification presumes a causal relationship between the linked conditions even without explicit provider documentation linking them.
Example: Documentation lists two conditions that the index links with the word with; they are coded as related without demanding an explicit provider statement of linkage.
Mistake to avoid: Requiring the provider to explicitly link conditions that the classification already presumes are related.
Reference: CDC ICD-10-CM Official Guidelines, FY 2027
6. Code Also Versus Use Additional Code
A code also note signals that two codes may be required to fully describe one condition but provides no sequencing direction, so order depends on the encounter. In contrast, use additional code and code first notes establish a required order, with the etiology sequenced before the manifestation.
Example: A condition carrying a code also note is sequenced according to the circumstances of the encounter rather than a fixed etiology-then-manifestation order.
Mistake to avoid: Assuming a code also note establishes a mandatory sequencing order it does not contain.
Reference: CDC ICD-10-CM Official Guidelines, FY 2027
Diagnosis Selection and Sequencing
7. Provider Statement Over Clinical Criteria
Code assignment rests on the provider's diagnostic statement that the condition exists, not on the clinical criteria, labs, or imaging the provider used to reach it. When record documentation conflicts, the correct response is to query the provider rather than choose between the statements.
Example: A cardiologist documents a diagnosis despite atypical findings; the coder assigns the stated diagnosis rather than second-guessing the workup that produced it.
Mistake to avoid: Overriding a provider's stated diagnosis because test results or clinical criteria appear inconsistent.
Reference: CDC ICD-10-CM Official Guidelines, FY 2027
8. Uncertain Diagnoses: Inpatient Versus Outpatient
Inpatient guidelines permit conditions documented as probable, suspected, or ruled out at discharge to be coded as if established. Outpatient services follow the opposite rule: code the symptoms or signs actually evaluated, and never report an unconfirmed probable diagnosis as if definitive.
Example: An office note lists possible pericarditis as the only assessment; the symptom code is reported instead of the pericarditis code.
Mistake to avoid: Coding a suspected outpatient diagnosis as confirmed instead of reporting the documented symptoms.
Reference: CDC ICD-10-CM Official Guidelines, FY 2027
9. Symptoms in Lieu of a Definitive Diagnosis
When no definitive diagnosis has been established by the end of the encounter, report codes for the sign or symptom in lieu of a diagnosis. Unspecified codes are acceptable and even necessary when they most accurately reflect what is known at that encounter.
Example: Chest pain evaluated without a confirmed cause is coded to the symptom, because the encounter's documented certainty ends at the symptom level.
Mistake to avoid: Assigning a specific diagnosis unsupported by the record simply to avoid a symptom or unspecified code.
Reference: CDC ICD-10-CM Official Guidelines, FY 2027
10. Acute and Chronic Conditions Together
When the same condition is documented as both acute or subacute and chronic, and separate subentries exist in the Alphabetic Index at the same indentation level, assign both codes and sequence the acute code before the chronic one.
Example: A note documents acute on chronic disease with distinct index subentries; both codes are assigned with the acute one listed first.
Mistake to avoid: Reporting only the chronic code when both the acute and chronic forms are documented.
Reference: CDC ICD-10-CM Official Guidelines, FY 2027
11. Combination Codes Replace Multiple Codes
A combination code captures two diagnoses, a diagnosis with a secondary manifestation, or a diagnosis with a complication in a single code. When a combination code fully identifies all the diagnostic conditions involved, assign only that code instead of using multiple coding.
Example: A single code fully describes a condition together with its associated process; reporting that one code alone is correct rather than stacking separate codes.
Mistake to avoid: Splitting a fully described condition into multiple codes when one combination code covers it.
Reference: CDC ICD-10-CM Official Guidelines, FY 2027
12. Laterality From Other Clinicians
Laterality is an exception to the rule that code assignment rests on the patient's own provider: documentation from other clinicians may establish the affected side. If documentation conflicts about the side, query the provider rather than defaulting to an unspecified side code.
Example: A nurse documents the affected side while the provider does not; the coder may rely on that documentation for side assignment without a query.
Mistake to avoid: Assigning an unspecified side code when another clinician clearly documented the affected side.
Reference: CDC ICD-10-CM Official Guidelines, FY 2027
E/M Leveling: MDM and Time
13. Leveling by MDM or Total Time
Office and outpatient E/M levels are selected using either the level of medical decision making or the total time for services performed on the date of the encounter, chosen case by case. Whichever basis is used, the documentation must still support the medical necessity of the visit.
Example: A visit with modest MDM but extensive same-day record review and coordination is leveled by total time because that basis supports the higher code.
Mistake to avoid: Mixing elements of both MDM and time in one visit to manufacture a higher level.
Reference: AAPC CCC study guide sample
14. History and Exam Do Not Set the Level
A medically appropriate history and/or physical examination, when performed, is included in the E/M service. History and exam should still be documented, but under current guidelines they are not used in determining the level of the code.
Example: A detailed exam paired with low-complexity MDM is coded at the level supported by MDM, not at the level the exam thoroughness suggests.
Mistake to avoid: Leveling a visit by the extent of the examination as under the retired 1995 and 1997 frameworks.
Reference: AAPC CCC study guide sample
15. The Three MDM Components
MDM is determined across three components: the number and complexity of problems addressed at the encounter, the amount and complexity of data reviewed and analyzed, and the risk of complications, morbidity, or mortality of patient management. The CPT code book definitions govern each component.
Example: A visit where data review and management risk both reach moderate complexity is assessed directly against the MDM table definitions in the code book.
Mistake to avoid: Estimating MDM levels from intuition instead of applying the CPT MDM table definitions.
Reference: AAPC CCC study guide sample
16. Problems Must Be Addressed to Count
For a problem to count in the number and complexity of problems addressed, it must be addressed within that encounter. Read the entire note rather than the chief complaint alone, because the full record reveals which conditions were truly assessed and managed.
Example: A historical condition merely listed is excluded from the count, while one assessed in the plan with findings and decisions counts toward leveling.
Mistake to avoid: Counting every condition in the past medical history as an addressed problem for the encounter.
Reference: AAPC CCC study guide sample
17. Comorbidities Require Addressing
Comorbidities and underlying diseases do not influence E/M level unless they are addressed during the encounter and their presence increases the amount or complexity of data reviewed or the risk of patient management. Simply listing a chronic illness in the documentation is not sufficient.
Example: Diabetes noted only in passing adds nothing to the level; documentation showing it complicated today's management decisions supports higher risk.
Mistake to avoid: Boosting a visit level because a chronic illness appears somewhere in the note.
Reference: AAPC CCC study guide sample
18. Conditions Managed by Another Provider
When a physician documents only that another provider manages a condition, that condition is not considered in leveling the visit. It becomes countable when additional documentation shows assessment of the condition or care coordination beyond the bare statement of external management.
Example: A note stating hypertension is managed elsewhere is excluded; a documented medication review and coordination with that provider makes the condition countable.
Mistake to avoid: Counting externally managed conditions toward MDM with no documented assessment or coordination.
Reference: AAPC CCC study guide sample
E/M Patient Status and Visit Rules
19. New Versus Established Patient Definition
A new patient is one who has not received any face-to-face professional services from the physician or qualified health care professional, or another of the same specialty and subspecialty within the same group practice, within the past three years. Professional services means face-to-face services.
Example: A patient saw a different cardiologist in the same group one year ago; today's visit with another group cardiologist is established, not new.
Mistake to avoid: Resetting new-patient status when the patient switches physicians within the same group and specialty.
Reference: AAPC CCC study guide sample
20. Three Requirements for a Consultation
A consultation under CPT requires three documented elements: a request from a physician or other qualified source, a service to recommend care or decide whether to accept ongoing management, and a written report back to the requesting provider. If any element is missing, a consultation code cannot be used.
Example: A cardiologist evaluates a patient at another physician's request but sends no written report; an office visit code is reported instead of a consultation code.
Mistake to avoid: Coding a consultation when the written report back to the requesting provider was never documented.
Reference: AAPC CCC study guide sample
21. CMS Consultation Non-Payment Substitution
CMS no longer reimburses consultation codes, so Medicare patients are coded with office and outpatient or hospital care codes instead. Apply this substitution only when the case note or question states Medicare coverage, and never assume Medicare coverage from the patient's age.
Example: A documented Medicare consultation is coded with an office visit code; a non-Medicare consult meeting all three CPT requirements keeps the consultation code.
Mistake to avoid: Assuming Medicare coverage from age and dropping a valid consultation code for a non-Medicare patient.
Reference: AAPC CCC study guide sample
22. Same-Day Admission From Another Site
When a patient is admitted to inpatient or observation status during an encounter that began in another site of service, such as the office or emergency department, the initial-site services may be separately reported. Modifier 25 is appended to that E/M to indicate a significant, separately identifiable service by the same professional on the same date.
Example: An office visit leads to a same-day admission; both the office E/M with modifier 25 and the admission code are separately reported.
Mistake to avoid: Dropping the initial-site E/M simply because the admission occurred later the same date.
Reference: AAPC CCC study guide sample
23. Initial Hospital Care by a Second Physician
When a patient is admitted by a physician of a different group and different specialty or subspecialty, a cardiologist seeing the patient for the first time during that admission reports an initial hospital care code. Each provider qualifies independently because they are of different groups and specialties.
Example: A primary care physician admits a patient; the cardiologist's first visit the next morning is coded as initial hospital care, not subsequent care.
Mistake to avoid: Reporting subsequent hospital care for the cardiologist's first visit merely because another physician admitted first.
Reference: AAPC CCC study guide sample
24. 99211 and the Absence of MDM
Code 99211 is reported for services that typically do not require the presence of a provider, which is why the concept of medical decision making does not apply to it. This code captures clinical staff work rather than physician or qualified health care professional decision making.
Example: A nurse checks a stable patient's blood pressure per protocol; 99211 is reported because no provider presence or medical decision making was involved.
Mistake to avoid: Attempting to level a 99211 claim using the medical decision making table.
Reference: AAPC CCC study guide sample
Billing Roles, Supervision, and Report Review
25. Split and Shared Visits in Facilities Only
A shared or split visit occurs when an NPP and a physician of the same group are both involved in one patient case. These rules apply only in facility settings, require face-to-face encounters by both, and the visit is billed by whoever performs the substantive, more-than-half portion.
Example: A hospital encounter where the NPP performs more than half the visit is billed under the NPP rather than the participating physician.
Mistake to avoid: Applying split/shared rules to an office encounter instead of using incident-to requirements.
Reference: AAPC CCC study guide sample
26. Incident-To Requirements in the Office
In the office setting, services involving NPPs do not follow split/shared rules; incident-to requirements apply instead. When those conditions are satisfied, the service is reported under the supervising physician, which distinguishes office billing from facility billing for the same kind of shared work.
Example: An established patient's office follow-up that meets incident-to conditions is billed under the supervising physician rather than the NPP.
Mistake to avoid: Using facility split/shared logic to bill an office visit performed with NPP involvement.
Reference: AAPC CCC study guide sample
27. Teaching Physician Participation
When residents or other trainees participate in care, teaching physician guidelines determine what the teaching physician must personally perform or be present for before the service can be billed under the physician. Without documented physician participation meeting the guideline, the trainee's work alone cannot be billed as physician work.
Example: A resident documents most of a visit, but the teaching physician's documented participation satisfies the guideline; the physician reports the service.
Mistake to avoid: Billing a service under the physician when the required teaching physician participation is not documented.
Reference: AAPC CCC study guide sample
28. Default to CPT Guidelines Unless Medicare Coverage Is Stated
The CCC examination tests coding concepts, anatomic principles, and coding guidelines only, so individual payer rules are not a consideration when choosing the right answer. Unless it is specifically stated in the case note or examination question that the patient is covered by Medicare, follow the CPT coding guidelines for code selection, bundling, and modifier use. Never assume Medicare coverage from the patient's age alone.
Example: A case note is silent about insurance, so the coder selects, sequences, and applies modifiers under CPT guidelines rather than any payer-specific policy, because Medicare rules attach only when the note or question identifies Medicare coverage.
Mistake to avoid: Applying Medicare-only rules to a case with no stated coverage, or assuming Medicare coverage from the patient's age.
Reference: AAPC CCC study guide sample
29. Purpose of the Advance Beneficiary Notice
An Advance Beneficiary Notice is used when Medicare coverage of a service is in doubt. A properly executed ABN informs the patient that Medicare may not pay and that the patient accepts potential financial responsibility, which permits billing the patient directly if the claim is denied.
Example: A service of uncertain Medicare coverage proceeds with a signed ABN; after denial, the practice may bill the patient for the service.
Mistake to avoid: Delivering a service expected to be denied without first obtaining a valid, signed ABN.
Reference: AAPC CCC study guide sample
30. Read the Entire Operative Report
Do not rely on the headers of an operative report. Additional procedures are sometimes performed but not listed in the header, and conversely a procedure named in the header may not actually have been performed. Verify every code against the complete body of the report.
Example: A header lists only diagnostic angiography, but the report body describes stent deployment; the stent is coded because the full report supports it.
Mistake to avoid: Coding from the procedure header alone and missing procedures documented in the report body.
Reference: AAPC CCC study guide sample
Echocardiography Coding
31. Complete Versus Limited 2D Echocardiography
A complete transthoracic 2D echo requires evaluation and documentation of all the structures that comprise the complete exam, or documentation of why a structure could not be visualized. If components are missing without explanation, report the follow-up or limited study code instead.
Example: An echo visualizes all structures except one, and the reason is documented; the complete code is reported rather than the limited study code.
Mistake to avoid: Reporting a complete study when unvisualized structures are present but never explained in the report.
Reference: AAPC CCC study guide sample
32. The Combined Comprehensive Echo Code
When a complete 2D study, complete spectral Doppler, and color flow Doppler are all performed and documented, report the single combined comprehensive code. That code specifically includes the work of the complete 2D, complete Doppler, and color flow components, so the individual codes are not reported.
Example: A comprehensive study with all three elements documented is reported with the combined code alone, not as three separate component codes.
Mistake to avoid: Unbundling a comprehensive study into separate 2D, Doppler, and color flow component codes.
Reference: AAPC CCC study guide sample
33. Parenthetical Prohibition Under the Complete 2D Code
A parenthetical note under the complete 2D echo code instructs not to report it in conjunction with the spectral Doppler and color flow add-on codes. Parenthetical notes and subsection guidelines control which code combinations are permissible, so they must be checked for every echo combination.
Example: A complete 2D echo performed without Doppler is reported alone; appending a Doppler add-on would violate the parenthetical prohibition.
Mistake to avoid: Stacking add-on Doppler codes onto a complete 2D echo when the parenthetical forbids it.
Reference: AAPC CCC study guide sample
34. Complete Versus Limited Spectral Doppler
A complete Doppler study examines every cardiac valve and the atrial and ventricular septa for antegrade and retrograde flow and provides functional hemodynamic data. A study that evaluates fewer structures is reported as the follow-up or limited Doppler study code.
Example: Doppler interrogating only the mitral valve for a known lesion is reported as the limited Doppler study, not the complete one.
Mistake to avoid: Reporting complete Doppler when only selected valves or flow areas were interrogated.
Reference: AAPC CCC study guide sample
35. Color Flow Reporting Without Complete or Limited Options
Color flow Doppler currently has no complete versus limited option. Report the color flow add-on code as long as the report clearly illustrates that color flow imaging was performed and documents the physician's findings and interpretation of the color flow data.
Example: A study documenting color flow assessment of regurgitant jets supports the color flow add-on code reported alongside the limited echo.
Mistake to avoid: Withholding the color flow code merely because the rest of the echo study was limited.
Reference: AAPC CCC study guide sample
36. Echo Report Content Requirements
For all 2D studies, the report must include interpretation of all information, documentation of clinically relevant findings including quantitative measurements, and a description of recognized abnormalities. Use of ultrasound without thorough evaluation, image documentation, and a final written report is not separately reportable.
Example: A limited echo with measurements, findings, and a written interpretation is separately reportable; a screening ultrasound without a final report is not.
Mistake to avoid: Reporting echocardiography from images alone without a final written interpretation.
Reference: AAPC CCC study guide sample
Stress Testing and Pharmacologic Stress
37. Global Stress Test Reporting in the Office
Report the global cardiovascular stress test code for testing performed in the office, where the physician provides supervision, interpretation, and the equipment or facility. This single code describes the full treadmill exercise or pharmacologic stress service in that setting.
Example: An office treadmill test with physician supervision, interpretation, and office equipment is reported with the single global code.
Mistake to avoid: Splitting an office stress test into technical and professional component codes.
Reference: AAPC CCC study guide sample
38. Hospital Setting Splits the Stress Test
In the hospital setting the global stress test code is not reported because it includes the technical portion of the exam. The physician instead reports supervision only and interpretation and report as separate codes, selecting each based on which portions the physician personally performed.
Example: A hospital pharmacologic stress test with physician supervision and interpretation is billed with the supervision code plus the interpretation code.
Mistake to avoid: Using the global stress test code for physician services performed in a hospital.
Reference: AAPC CCC study guide sample
39. Combined Stress Echo Code in the Office
In the office setting, when the physician performs all the work of the stress echo and all the work of the treadmill exercise, report the combined stress echo code rather than separately reporting the stress echo and stress test codes. A parenthetical note under the combined code directs this.
Example: An office stress echo with rest and stress imaging plus supervised exercise is reported with the single combined code, not the two component codes.
Mistake to avoid: Reporting the stress echo and stress test codes separately for a fully physician-performed office service.
Reference: AAPC CCC study guide sample
40. Contrast Administration With Stress Echo
When an echocardiographic contrast agent is administered during a stress echo, report the contrast add-on code in addition to the code for the primary procedure, when the use is documented. The add-on structure means it is never reported alone and always accompanies the stress echo code.
Example: Contrast enhancement clarifies left ventricular borders during a stress echo; the contrast add-on code accompanies the primary stress echo code.
Mistake to avoid: Omitting the contrast add-on code when the report clearly documents contrast use.
Reference: AAPC CCC study guide sample
41. Documenting the Reason for Pharmacologic Stress
When exercise is not possible and pharmacologic stress is used instead, the reason must be documented, for example dizziness, a prosthetic limb, or arthritis. The stress test codes themselves cover treadmill or bicycle exercise and/or pharmacologically induced stress, so the agent choice does not change the code.
Example: A note cites severe arthritis preventing treadmill use; the pharmacologic stress test is coded with the reason for drug stress documented.
Mistake to avoid: Coding pharmacologic stress without documenting why the patient could not exercise.
Reference: AAPC CCC study guide sample
42. Pharmaceutical Reporting Differs by Setting
For office-based studies, the pharmaceutical used, when supplied by the office, may also be reported. The hospital facility reports the pharmaceutical for tracking purposes as well, but the cost there is included in the procedure, so facility tracking does not translate into separate physician billing.
Example: An office-supplied stress agent is separately reported by the practice; the hospital's tracking report does not create separate physician payment.
Mistake to avoid: Separately billing the stress agent in the hospital setting where its cost is bundled.
Reference: AAPC CCC study guide sample
Catheter Placement and Angiography
43. Nonselective Catheter Placement Defined
Nonselective catheter placement describes movement toward or into the aorta from any access point, for instance catheter placement into a lower extremity artery with upstream advancement into the aorta. Injections performed through the sheath are considered nonselective and are coded accordingly.
Example: Contrast injected through the sheath at the access site is nonselective; the nonselective catheter placement code is reported for that access.
Mistake to avoid: Coding a sheath injection as if it were a selective catheter placement.
Reference: AAPC CCC study guide sample
44. Above Versus Below the Diaphragm Code Families
Selective catheter placement codes come in two families: one for vascular families branching off the aorta above the diaphragm and one for those below it. Choose the family that matches the vascular territory actually catheterized during the procedure, not the access site alone.
Example: A catheter advanced to the popliteal artery uses the below-diaphragm family because the entire procedure stayed below the diaphragm.
Mistake to avoid: Selecting an above-diaphragm code for a catheter position reached entirely below the diaphragm.
Reference: AAPC CCC study guide sample
45. Order of Selectivity Within a Vascular Family
Within a vascular family, code by the highest order of selectivity reached: each first order branch, initial second order branch, or initial third order or more selective branch. Additional second- and third-order placements beyond the initial one are captured with the additional-placement add-on codes.
Example: The catheter's final position is a third-order branch within the vascular family; the initial third-order selective code is reported for the case.
Mistake to avoid: Coding every branch the catheter passed through instead of the highest order actually reached.
Reference: AAPC CCC study guide sample
46. Additional Vessel Angiography Add-On Code
The add-on angiography code for each additional vessel studied after the basic examination applies when an additional selective study is performed within the same anatomic area as a complete diagnostic study already reported. The additional study must be performed from a selective catheter position to qualify.
Example: After an initial extremity study, repositioning to the distal popliteal artery for further imaging supports the additional-vessel add-on code.
Mistake to avoid: Overlooking the additional-vessel add-on when imaging continues beyond the initial basic study.
Reference: AAPC CCC study guide sample
47. Unilateral Versus Bilateral Extremity Angiography
Extremity angiography supervision and interpretation codes distinguish unilateral from bilateral studies. A study is bilateral when both extremities are imaged, whether through separate injection points or a contralateral injection combined with a sheath shot, and the bilateral code is then reported.
Example: A right leg study plus a sheath shot of the left leg is reported as a bilateral extremity angiogram, not a unilateral one.
Mistake to avoid: Reporting a unilateral code when the documentation shows both extremities were imaged.
Reference: AAPC CCC study guide sample
48. Femoral Arteriogram: Two Separate Components
For a femoral arteriogram, code the catheter insertion and the radiology supervision and interpretation as separate services. The catheter placement is reported with the nonselective placement code, and the imaging is reported with the unilateral or bilateral extremity angiography code as performed.
Example: A unilateral femoral arteriogram reports the arterial access placement code together with the unilateral extremity imaging code.
Mistake to avoid: Bundling the catheter insertion into the imaging code when reporting extremity angiography.
Reference: AAPC CCC study guide sample
Interventions and Procedure Sequencing
49. Stents Are Reported Per Vessel
Stent placement codes are reported per vessel, not per stent. If two stents are deployed in the same vessel, the procedure is reported only once for that vessel, regardless of how many devices were required to complete the treatment.
Example: Two stents are deployed in one vessel at separate stenoses; the stent code is reported a single time for that vessel.
Mistake to avoid: Reporting each deployed stent as if it were a separate billable procedure.
Reference: AAPC CCC study guide sample
50. Angioplasty Per Vessel and Its Inclusion Rule
Angioplasty codes are reported per vessel, not per angioplasty. Angioplasty performed at two separate sites of the same vessel is reported once, and angioplasty is considered included when other interventions, such as stent placement or atherectomy, are performed in the same vessel.
Example: Balloon dilation at two stenoses in one vessel followed by stenting reports only the stent code for that vessel.
Mistake to avoid: Separately reporting angioplasty performed in a vessel that also received a stent or atherectomy.
Reference: AAPC CCC study guide sample
51. Catheter Placement Included in Intervention Codes
Catheter placement performed to access the vessel for angioplasty or stent deployment is included in the intervention code and is not separately reported. This inclusion applies to the access work for the intervention itself, distinguishing it from separately reportable diagnostic catheter placements.
Example: Access catheterization performed to deploy a stent is bundled; only the stent code is reported for that vessel.
Mistake to avoid: Adding a selective catheter placement code for the access used solely to perform the intervention.
Reference: AAPC CCC study guide sample
52. Carotid Selective Hierarchy and Bilateral Reporting
Selective catheter placement of the carotid arteries is reported on a hierarchy. The internal carotid code includes the service performed on the common carotid of the same side, so only the highest-level code is reported. Bilateral performance appends modifier 50, and add-on codes are reported twice for bilateral procedures.
Example: Selective placement in the right internal and right common carotids reports only the internal carotid code, because it includes the common carotid service.
Mistake to avoid: Reporting both the internal and common carotid codes for placements performed on the same side.
Reference: AAPC CCC study guide sample
53. Different-Side Carotid Placements Use Modifier 59
When carotid selectivity differs between sides, such as internal carotid catheterization on the left and common carotid on the right, report the distinct placement codes for each side. Append modifier 59 to indicate the procedures were separate, because the same-side hierarchy and bilateral modifier do not fit this situation.
Example: Left internal and right common carotid placements are reported as distinct codes with modifier 59 appended to show separate procedures.
Mistake to avoid: Appending modifier 50 when the two sides required different-order selective placements.
Reference: AAPC CCC study guide sample
54. Sequencing Multiple Procedures by Complexity
When multiple procedures are performed and reported together, sequence the CPT codes with the most complex or labor-intensive procedure first. The codes with the highest relative value units are sequenced first, which means report order reflects procedural weight rather than the chronology of the operative narrative.
Example: A case combining diagnostic angiography with an intervention lists the intervention code first because it carries the higher relative value units.
Mistake to avoid: Sequencing codes in the order the procedures happen to appear in the report narrative.
Reference: AAPC CCC study guide sample
HIPAA Privacy and Compliance
55. Who Is a Covered Entity
The Privacy Rule applies to health plans, health care clearinghouses, and any health care provider who transmits health information electronically in connection with standard HIPAA transactions, such as claims, eligibility inquiries, or referral authorization requests. Using email alone does not make a provider covered; the transmission must involve a standard transaction.
Example: A cardiology practice submitting electronic claims is a covered entity; a practice transmitting no standard transactions is not automatically one.
Mistake to avoid: Assuming every healthcare business is covered regardless of whether it transmits standard electronic transactions.
Reference: HHS Summary of the HIPAA Privacy Rule
56. Protected Health Information in Any Form
Protected health information is individually identifiable health information held or transmitted by a covered entity or its business associate in any form or media, whether electronic, paper, or oral. It includes demographic data relating to health, care, or payment that identifies the individual or could reasonably be used to identify them.
Example: A hallway conversation about a patient's echo results that includes identifying detail involves protected health information.
Mistake to avoid: Treating oral communications as outside privacy protections because they are not written or electronic.
Reference: HHS Summary of the HIPAA Privacy Rule
57. The Minimum Necessary Standard
Covered entities must make reasonable efforts to use, disclose, and request only the minimum amount of protected health information needed to accomplish the intended purpose. The standard does not apply to disclosures for treatment, to the individual, under an authorization, to HHS for enforcement, or when required by law.
Example: A payer request supporting claim adjudication receives only the relevant encounter documentation rather than the patient's complete chart.
Mistake to avoid: Sending an entire medical record when only specific encounter documentation is needed for the purpose.
Reference: HHS Summary of the HIPAA Privacy Rule
58. Treatment, Payment, and Operations Disclosures
A covered entity may use and disclose protected health information without individual authorization for its own treatment, payment, and health care operations. It may also disclose for the treatment activities of any provider, the payment activities of other entities, and certain operations of other covered entities that have a relationship with the patient.
Example: Sending records to a referring cardiologist for ongoing care is a treatment disclosure requiring no signed authorization from the patient.
Mistake to avoid: Delaying provider-to-provider care coordination while waiting for a signed authorization that is not required.
Reference: HHS Summary of the HIPAA Privacy Rule
59. Business Associates and Written Agreements
A business associate is a person or organization outside the covered entity's workforce that performs functions on its behalf involving protected health information, such as claims processing, billing, or data analysis. A written business associate agreement imposing specified safeguards is required, and a covered entity may serve as another covered entity's business associate.
Example: An outside billing service handling the practice's claims must operate under a business associate agreement before receiving patient records.
Mistake to avoid: Exchanging PHI with a billing contractor without a written business associate agreement in place.
Reference: HHS Summary of the HIPAA Privacy Rule
60. Authorization Requirements and Marketing
Written authorization is required for any use or disclosure of protected health information beyond permitted purposes, including marketing arrangements where the covered entity receives direct or indirect remuneration for communicating about another entity's products. Authorizations must be in plain language, specify the information and parties, include an expiration, and be revocable.
Example: A drug company paying the practice to send patients promotional communications requires a signed authorization that reveals the remuneration.
Mistake to avoid: Treating remunerated third-party marketing as an ordinary health care operations activity needing no authorization.
Reference: HHS Summary of the HIPAA Privacy Rule
References and further reading
Source links checked on Oct 2, 2026.