Diagnostic Coding and Reporting Guidelines for Outpatient Services

These coding guidelines for outpatient diagnoses have been approved for use by hospitals/ providers in coding and reporting hospital-based outpatient services and provider-based office visits. Guidelines in Section I, Conventions, general coding guidelines and chapter-specific guidelines, should also be applied for outpatient services and office visits.

Information about the use of certain abbreviations, punctuation, symbols, and other conventions used in the ICD-10-CM Tabular List (code numbers and titles), can be found in Section IA of these guidelines, under “Conventions Used in the Tabular List.” Section I.B. contains general guidelines that apply to the entire classification.

Section I.C. contains chapter-specific guidelines that correspond to the chapters as they are arranged in the classification. Information about the correct sequence to use in finding a code is also described in Section I. The terms encounter and visit are often used interchangeably in describing outpatient service contacts and, therefore, appear together in these guidelines without distinguishing one from the other.

Though the conventions and general guidelines apply to all settings, coding guidelines for outpatient and provider reporting of diagnoses will vary in a number of instances from those for inpatient diagnoses, recognizing that: The Uniform Hospital Discharge Data Set (UHDDS) definition of principal diagnosis does not apply to hospital-based outpatient services and provider-based office visits.

Coding guidelines for inconclusive diagnoses (probable, suspected, rule out, etc.) were developed for inpatient reporting and do not apply to outpatients.