CCS (AHIMA) key terms

The U.S. diagnosis classification used on inpatient and outpatient claims, with more than 70,000 codes organized by body system and chapter. It replaced ICD-9-CM volumes 1 and 2 in 2015.

The U.S. inpatient procedure classification. Each seven-character alphanumeric code is built from independent axes such as root operation, body part, approach, and device, and is used only on inpatient hospital claims.

The American Medical Association's code set of five-digit codes and modifiers that describes medical, surgical, and diagnostic services. It is used mainly to report professional services on outpatient and physician claims.

A national alphanumeric code set maintained by CMS for supplies, drugs, durable medical equipment, prosthetics, and services not described by CPT. Medicare and many other payers require it on claims.

The condition established after study to be chiefly responsible for occasioning the inpatient admission, per the Uniform Hospital Discharge Data Set definition. It is sequenced first and drives MS-DRG assignment.

Any additional condition that coexists at admission or develops during the stay and affects patient care, length of stay, or resource use. It may act as a CC or MCC and must be documented.

The inpatient procedure performed for definitive treatment of the principal diagnosis rather than for diagnostic or exploratory purposes, or the one needed to treat a complication. It is sequenced first among procedures.

A single code that classifies two diagnoses together, or a diagnosis with an associated complication or manifestation. When the alphabetic index offers one, it is used instead of separate codes.

An ICD-10-CM instruction meaning the two conditions are mutually exclusive and cannot be coded together. The excluded condition is never reported with the code carrying the note.

A residual condition that remains after the acute phase of an illness or injury has ended. In ICD-10-CM the sequela is coded first, followed by the original condition with the appropriate seventh character.

Medicare Severity Diagnosis Related Group. The inpatient prospective payment grouping that assigns a fixed payment based on principal diagnosis, performed procedures, and the presence of complications or comorbidities.

Complication or comorbidity (CC) and major complication or comorbidity (MCC): secondary diagnoses that raise an MS-DRG's severity level and payment. They must be documented, codable, and generally present on admission.

A CPT modifier added to an evaluation and management code when a significant, separately identifiable E/M service is performed on the same day as a procedure by the same physician.

The preoperative, intraoperative, and postoperative care bundled into a single surgical CPT code payment, typically covering zero, ten, or ninety days after the procedure.

A claim flag showing whether a secondary diagnosis was present when the patient was admitted. Diagnoses not present on admission generally cannot act as CCs or MCCs to raise MS-DRG payment.

The category and complexity assigned to an evaluation and management visit, chosen using either the 1995/1997 documentation guidelines or the current medical decision making and time framework.

The annual coding rules issued by the cooperating parties (AHA, AHIMA, CMS, and NCHS) that govern correct ICD-10-CM and ICD-10-PCS code assignment and sequencing.

The American Hospital Association's quarterly publication of official ICD-10-CM/PCS coding advice and questions submitted by the field. Its guidance is treated as authoritative when assigning codes.

National Correct Coding Initiative edits that pair codes which should not be billed together because the services overlap. Procedure-to-procedure and medically unlikely edits flag improper combinations.

Reporting components of a bundled service or procedure as separate codes in order to obtain higher payment. NCCI edits and CPT bundling rules define which of these combinations are improper.

Assigning a code for a more severe diagnosis, higher-level service, or more complex procedure than the documentation supports, which overstates payment. It is a fraud and abuse risk.

The standard requiring services to be reasonable and necessary for diagnosing or treating illness, supported by payer coverage policy and documented in the patient record.

The surgeon's narrative describing a procedure, including findings, technique, specimens, devices, and estimated blood loss. Coders rely on it to assign accurate procedure codes.

The physician's closing summary of a hospitalization covering the reason for admission, significant findings, procedures performed, discharge diagnoses, and follow-up instructions. It helps confirm the principal diagnosis.

The admission document recording chief complaint, history of present illness, past medical history, medications, allergies, physical examination, and initial impressions that establish diagnoses at entry.

A dated entry in the record describing the patient's current clinical status, examination findings, and treatment plan during a stay or visit, used to support diagnoses and find query opportunities.

A collaborative program in which coders and clinicians work to make the record accurately and completely reflect the patient's severity of illness, treatments, and outcomes.

A compliant written or electronic question to the provider requesting clarification or additional documentation needed to assign a code, MS-DRG, or quality measure that the record does not clearly support.

A noncompliant query that suggests a specific diagnosis, offers only one plausible answer, or reveals reimbursement or quality impact, thereby steering the provider instead of seeking independent clinical judgment.

A query asking the provider to confirm that a documented diagnosis is clinically supported by the record, such as a sepsis diagnosis lacking supporting clinical indicators, before that diagnosis is coded.

An organization's structured set of policies, training, auditing, monitoring, and reporting channels designed to prevent, detect, and correct violations of billing and healthcare regulations, following OIG guidance.

A CMS form a provider gives a Medicare beneficiary before a service that may be denied as not medically necessary, so the patient knows and accepts potential financial liability.

National Coverage Determination and Local Coverage Determination: Medicare policies stating the conditions under which an item or service is covered, used to test medical necessity before coding and billing.

The federal regulation setting national standards to protect individually identifiable health information, defining permitted uses and disclosures and giving patients rights over their records.

A CMS-contracted reviewer that examines Medicare claims after payment to identify and recover improper overpayments and to return underpayments to providers.

The Office of Inspector General of the U.S. Department of Health and Human Services, which audits and investigates Medicare and Medicaid fraud and publishes compliance guidance and work plans.

Software that converts documented conditions and procedures into candidate codes and applies edit and DRG grouper logic. Coders must verify every encoder suggestion against the source documentation.

Natural language processing software that reads clinical text and proposes candidate codes for coder review. It supports but never replaces the coder's judgment and final code assignment.

An electronic health record: a digital longitudinal record of a patient's encounters, test results, and clinical documentation that serves as the primary source for coding and query activity.

The database that assigns a unique identifier to each patient and links all of that person's records, preventing duplicate or fragmented identities that would corrupt coding and reporting.