Clinical Documentation Improvement (CDI): A Practical Guide to Compliant Queries

Codes can only be as accurate as the record. Clinical documentation improvement (CDI) programs review documentation — usually while the patient is still in care — and work with providers to make it complete, specific, consistent and clinically supported.

Why documentation matters

Documentation drives:

• Code assignment — specificity, acuity, and cause-and-effect relationships must be documented by a provider to be coded.
• Payment — MS-DRG severity (CC/MCC), APCs and HCCs all depend on documented diagnoses and procedures.
• Quality and outcomes data — risk-adjusted mortality, complications and readmission measures use coded data.
• Audit defense — a diagnosis without clinical support is vulnerable to clinical validation denials.

Inpatient and outpatient CDI

Inpatient CDI traditionally focuses on principal diagnosis, CC/MCC capture, severity of illness and risk of mortality, and procedure documentation. Outpatient CDI has grown alongside risk adjustment, focusing on chronic condition specificity and annual capture, plus documentation for E/M levels and medical necessity.

What is a compliant query?

A query is a communication to a provider asking for clarification of documentation. The joint AHIMA/ACDIS Guidelines for Achieving a Compliant Query Practice are the industry standard. Core principles:

• Query when documentation is conflicting, incomplete, ambiguous, illegible or lacks clinical support.
• Include the clinical indicators from the record that prompted the question.
• Never lead. Do not indicate the financial or quality impact, and do not present only the desired answer.
• Offer clinically reasonable options, including options such as "other" and "unable to determine" in multiple-choice queries.
• Use yes/no questions only in limited circumstances — not to establish a new diagnosis.
• Keep queries as part of the permanent business or medical record according to organizational policy.

Clinical validation

Clinical validation asks whether a documented diagnosis is supported by clinical criteria — separate from whether it was coded correctly. Payers increasingly deny claims on clinical validation grounds (for example, for sepsis, malnutrition or acute respiratory failure). CDI and coding teams should agree with providers on the clinical criteria the organization uses and query when documentation does not meet them.

Building a strong CDI program

Related reading

• HCC risk adjustment coding guide
• FY 2027 IPPS final rule: what changed?