Sequencing, Code First, Use Additional Code, and Excludes Notes

NHA Certified Billing and Coding Specialist CBCS

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1 Introduction and 2026 CBCS Exam Facts

Official 2026 CBCS Exam Facts How to Use This Guide Scoring, Time, and Question Strategy Current Manual Policy and Official Resources

2 Revenue Cycle Foundations

Revenue Cycle Map Patient Access to Charge Capture Claim to Payment Workflow Error Prevention and Rework Loops

3 Regulatory Compliance for Billing and Coding

HIPAA Privacy, Security, and Breach Recognition HITECH, FCA, Stark Law, and Anti-Kickback Basics OIG, Compliance Plans, and Audits Fraud, Abuse, and Documentation Risk

4 Confidentiality, Consent, and Professional Communication

PHI Identifiers and Minimum Necessary Consent, Authorization, and Release of Information Communicating with Patients, Providers, and Payers Ethical Escalation and Documentation Habits

5 Insurance Products and Payer Types

Commercial Plan Types Medicare, Medicaid, and TRICARE Secondary Payers, COB, and the Birthday Rule Workers' Compensation, Auto, and Other Third-Party Payers

6 Eligibility, Benefits, and Authorization

Intake Documents and Insurance Cards Eligibility, Benefits, Copay, Deductible, and Coinsurance Referrals, Preauthorization, and Predetermination ABN, Medical Necessity, and Self-Pay Workflows

7 Clinical Documentation and Abstraction

Anatomy, Terminology, and Acronyms Locating Relevant Documentation Abstracting Diagnoses, Procedures, and Services Provider Queries and Documentation Clarity

8 ICD-10-CM Guidelines and Sequencing

ICD-10-CM Structure, Conventions, and Notes Specificity, Laterality, and Episode of Care Sequencing, Code First, Use Additional Code, and Excludes Notes Medical Necessity and Diagnosis Support

9 CPT, E/M, and Procedure Coding

CPT Structure, Sections, and Symbols E/M Leveling, MDM, and Time Procedure Coding and Global Periods Specialty and Telehealth Coding Considerations

10 HCPCS, Modifiers, and Code Edits

HCPCS Level II and Medicare Codes High-Yield Modifiers NCCI, MUE, Bundling, and Unbundling Place of Service, Units, and Payer-Specific Rules

11 Claim Forms and Required Fields

CMS-1500 Professional Claims UB-04 Institutional Claims Diagnosis Pointers, Charges, Units, and NPIs Clean Claim Checklists

12 Electronic Claims, EDI, and Clearinghouses

EDI Transaction Map: 837, 835, 270, 271, 277CA, and 999 Clearinghouse Scrubbing and Front-End Rejections Payer-Specific Submission Rules Resubmission, Correction, and Timely Filing

13 Adjudication, Remittance, and Payment Posting

Adjudication Outcomes, Allowed Amounts, and Contractuals EOB, ERA, RA, CARC, and RARC Reading Patient, Payer Responsibility, and Secondary Billing Payment Posting, Adjustments, Writeoffs, and Credit Balances

14 Denials, Appeals, and Accounts Receivable Follow-Up

Rejections Versus Denials Denial Root Cause Analysis and Corrections Reconsiderations, Appeals, and Medicare Appeal Levels Aging Reports, Prioritization, and Follow-Up Notes

15 Patient Financial Responsibility

Estimates, Copays, Deductibles, and Coinsurance Assignment of Benefits and Financial Policies Statements, Payment Plans, and Hardship Workflows Collections Communication and FDCPA Awareness

16 Reporting, Reconciliation, and Revenue Cycle Improvement

Daily Balancing, Batches, and Deposits Productivity, Quality, and Denial Metrics Payer Trends, Contract Review, and Process Improvement Audit Trails, Documentation, and Compliance Reporting

17 Integrated CBCS Case Labs

New Patient Office Visit Case Diagnostic Test Authorization Case Surgical Global Period and Modifier Case Denial to Appeal Case

18 High-Yield CBCS Exam Traps

Sequencing Versus Bundling Traps Eligibility Versus Authorization Traps Privacy Versus Release of Information Traps Rejection, Denial, Write-Off, and Appeal Traps

19 Study Plan and Domain Remediation

Six-Week Study Plan Two-Week Final Review Plan Using Score Reports and Practice Data Building a Missed-Question Log

20 Exam-Day Readiness and Next Steps

Scheduling Deadlines and Test Delivery Pacing, Flagging, and Answer Changing After the Exam: Results, Retakes, and Renewal Career Next Steps After CBCS

Sequencing, Code First, Use Additional Code, and Excludes Notes

Key Takeaways Explain This Topic AI

Sequencing determines the order of diagnosis codes and can affect medical necessity, reimbursement, reporting, and claim edits.

Code first notes require an underlying condition or cause to be listed before a related manifestation or complication code.

Use additional code notes require another code when documented to fully describe the case, such as organism, exposure, drug use, or stage.

Excludes1 generally prevents reporting two codes together for the same condition, while Excludes2 allows both codes if both conditions exist.

The first-listed diagnosis for many outpatient encounters is the condition, problem, or reason chiefly responsible for the service.

Last updated: April 2026

Sequencing is the order in which diagnosis codes appear on the claim. It is not cosmetic. The first-listed or principal diagnosis can affect whether a service is covered, how the claim is routed, whether an edit fires, and how the encounter is counted in data reporting. For CBCS candidates, sequencing requires combining documentation with ICD-10-CM instructions. The question may provide the codes and notes; the candidate must choose the order that follows the rules. In many outpatient settings, the first-listed diagnosis is the condition, problem, or reason chiefly responsible for the encounter.

Key Concepts

If a patient presents for evaluation of cough and fever and the provider diagnoses influenza, influenza may be first-listed. If the provider does not establish a definitive diagnosis, the symptoms may be first-listed. If the encounter is for a screening service and the patient has no symptoms, a screening code may be first-listed. If a patient comes for follow-up after completed treatment, an aftercare or follow-up code may be appropriate depending on the circumstances and code set instructions.

In inpatient facility coding, principal diagnosis rules differ, but the CBCS billing focus still requires understanding that code order must follow the setting and instructions supplied. Code first notes are mandatory sequencing directions. They tell the coder that another condition, usually the underlying disease or cause, must be sequenced before the code being considered. This often appears with manifestation codes, complications, or conditions caused by another condition.

For example, a manifestation of diabetes may require the diabetes combination code or underlying condition to be sequenced according to the code instructions.

A code first note is not a suggestion to consider later; it is part of the code assignment rule. If the underlying condition is not documented, the coder cannot invent it simply to satisfy a note. In that situation, the coder may need a different code or a query, depending on the documentation. Use additional code notes are also mandatory when the additional detail is documented and relevant. They instruct the coder to add another code to fully describe the case.

Workflow and Documentation

Examples include infectious organism, tobacco exposure or dependence, alcohol use, long-term insulin or oral antidiabetic drug use, external cause, stage of chronic kidney disease, or adverse effect details. The additional code usually comes after the main condition unless another guideline says otherwise. The phrase code also may indicate that two codes may be needed, but sequencing may depend on the circumstances of the encounter. Candidates should read the exact note in the question and apply it literally. Excludes notes help prevent incompatible or incomplete coding.

Excludes1 generally means the excluded condition should not be coded at the same time as the code above the note for the same condition. It may mean not coded here because the two diagnoses cannot occur together, or because one concept is included elsewhere. Excludes2 means the excluded condition is not included in the code, so both may be reported if the patient has both. For example, if a code excludes a congenital form of a condition with Excludes2, and the patient has both the acquired condition and a separate congenital condition, both may be reportable if documented.

The exam may ask which codes can be reported together based on an Excludes note. The answer depends on the type of Excludes note. Sequencing also interacts with combination codes. A combination code can describe two diagnoses, a diagnosis with a manifestation, or a diagnosis with a complication. When a combination code fully describes the documented condition, separate codes for the same components may not be needed unless the instructions say to add more detail. For example, a code may include both diabetes and neuropathy, or hypertension and heart disease under specific guideline conditions.

Exam Application

Reporting separate codes that duplicate the combination code can be incorrect. Medical necessity adds another layer. The diagnosis linked to a procedure should explain the reason for that procedure. If a patient has both knee pain and hypertension, knee pain may support a knee X-ray, while hypertension supports blood pressure management. The order of codes and diagnosis pointers should reflect the services billed. When a question includes Medicare coding requirements, local coverage concepts, or payer instructions, follow the supplied requirement.

Practical sequencing steps are: identify the encounter reason, check whether a definitive diagnosis was established, look for screening, aftercare, injury, complication, or sequela logic, read all code first and use additional code notes, apply Excludes notes, avoid duplicate coding, and link diagnoses to the services they support.

High-Yield Checkpoints

Sequencing determines the order of diagnosis codes and can affect medical necessity, reimbursement, reporting, and claim edits.

Code first notes require an underlying condition or cause to be listed before a related manifestation or complication code.

Use additional code notes require another code when documented to fully describe the case, such as organism, exposure, drug use, or stage.

Excludes1 generally prevents reporting two codes together for the same condition, while Excludes2 allows both codes if both conditions exist.

The first-listed diagnosis for many outpatient encounters is the condition, problem, or reason chiefly responsible for the service.