ACDIS CCDS key terms

A payment category used by Medicare to group inpatient stays that consume similar hospital resources. Each stay is assigned one DRG based on principal diagnosis, procedures, and secondary diagnoses, and the hospital is paid a fixed amount for it.

The Medicare payment system that pays acute care hospitals a predetermined amount per inpatient discharge rather than for each individual service. Payment is based on the assigned MS-DRG and adjusted for geographic and teaching factors.

A hospital's average DRG relative weight across its discharges. It reflects how sick, on average, the patients treated are; a rising CMI suggests more complex cases or better documentation of severity.

Secondary diagnoses that CMS designates as complications or comorbidities (CC) or major complications or comorbidities (MCC). When present and clinically supported, they raise the MS-DRG severity level and increase payment.

A number expressing how resource-intensive a DRG is compared with the average Medicare case. It is multiplied by the hospital's base payment rate to determine the payment for a stay.

The condition established after study to be chiefly responsible for the inpatient admission. It determines DRG assignment and is defined in the UHDDS and the official coding guidelines.

Any condition other than the principal diagnosis that coexists at admission or develops during the stay and affects care, treatment, or length of stay. Only documented, clinically supported conditions should be reported.

A flag on each inpatient diagnosis showing whether the condition was present when the patient was admitted. POA status affects payment, quality reporting, and hospital-acquired condition penalties.

The standardized set of data elements hospitals report for inpatient discharges. It supplies the national definitions of principal diagnosis, other diagnoses, and procedure coding that drive DRG assignment.

The American Hospital Association's official quarterly guidance on ICD-10-CM and ICD-10-PCS coding questions. Its advice is treated as authoritative by CMS and payers when code assignment is unclear.

Documentation that connects a condition to its underlying cause, such as 'diabetic foot ulcer' or 'encephalopathy due to sepsis.' Coders need this causal statement to assign combination codes or secondary codes correctly.

CMS's expectation that an inpatient admission is generally appropriate when a physician reasonably expects the patient to need hospital care spanning at least two midnights. Stays not meeting this benchmark may be billed as observation.

A code used when a hospital, after a physician advisor and utilization review agree, changes a patient's status from inpatient to outpatient during the stay. The stay is then billed as outpatient.

The requirement that services be reasonable and necessary for diagnosing or treating a condition and meet payer coverage criteria. Documentation must support both the level of care and the services billed.

A condition acquired during hospitalization that CMS considers reasonably preventable. Hospitals receive reduced payment for HAC-related cases and may face additional quality penalties.

An outpatient status for patients who need monitoring or evaluation but do not clearly require inpatient admission. It affects patient cost-sharing, skilled nursing eligibility, and whether the stay counts as an inpatient discharge.

Medicare contractors that audit claims and recover improper payments. Their reviews target high-risk DRGs and documentation patterns, so accurate, complete records are the main defense.

A life-threatening organ dysfunction caused by a dysregulated response to infection. Documentation should identify the source of infection, the organ dysfunction involved, and any causal link between them.

Inability of the lungs to maintain adequate gas exchange, documented with hypoxemia or hypercapnia and often requiring oxygen or mechanical support. Acute and chronic types are coded separately and carry different severity.

A general term for altered brain function caused by infection, metabolic derangement, drugs, or other factors. Documentation should specify the type and cause; 'altered mental status' alone does not support the diagnosis.

A deficiency or imbalance in nutrient intake that produces measurable clinical changes. Clinicians should document the severity and the criteria used, because coding requires a physician diagnosis rather than lab values alone.

A sudden decline in kidney function marked by rising creatinine or falling urine output. Documentation should distinguish it from chronic kidney disease and identify any stage or underlying cause.

A condition in which the heart cannot pump or fill adequately for the body's needs. Specificity includes acuity (acute, chronic, acute on chronic) and type (systolic, diastolic), which change DRG severity.

The use of medications such as heparin or warfarin to prevent blood clots. CDI specialists track it because bleeding risks and drug interactions can affect diagnoses, length of stay, and severity of illness.

Objective findings such as lab values, vital signs, imaging results, and medications that support a diagnosis. CDI specialists use them to recognize when documentation may be incomplete and a query is warranted.

The physician or non-physician practitioner's record of diagnoses, clinical findings, and treatment. It is the legal source for code assignment; a condition that is not documented cannot be coded.

Repeating or carrying forward text from earlier notes, which can produce inaccurate or unsupported documentation. It undermines record integrity and may trigger audits, denials, and compliance concerns.

The clinician's summary of the hospitalization, including diagnoses, hospital course, and follow-up plan. CDI specialists review it because it often clarifies or contradicts diagnoses documented earlier in the stay.

A communication tool used by CDI or coding staff to ask a provider to clarify or add documentation when the record is ambiguous, incomplete, or conflicting. The provider's response must be documented in the record.

A query that suggests the answer the specialist expects, such as proposing a diagnosis the provider never stated. It is non-compliant because it can introduce unsupported diagnoses into the record.

A written query listing plausible options plus an open line for the provider's own answer. It keeps the question focused while avoiding steering the provider toward a particular diagnosis.

Ongoing feedback to physicians and other clinicians about documentation expectations, query results, and coding impacts. Effective programs use real cases and are delivered promptly so behavior actually changes.

The process of involving a physician advisor, department chair, or other leader when a provider does not respond to a query or disagrees. It protects both compliance and the timeliness of the record.

The process of tracking, appealing, and preventing payer denials. Root-cause analysis of denials often reveals documentation gaps that the CDI team can address upstream.

Comparing a CDI program's results, such as query rate or case-mix index, with peer hospitals or national data. Benchmarks show where performance is strong and where improvement work is needed.

The percentage of eligible cases whose documented CCs or MCCs are actually captured in coding. It is a common measure of documentation completeness and CDI program effectiveness.

A ratio comparing observed deaths with deaths predicted from the severity of the patients treated. Better documentation of comorbidities can change expected mortality and affect published rankings.