Inpatient Claim Diagnosis Reporting
On inpatient claims providers must report the principal diagnosis. The principal diagnosis is the condition established after study to be chiefly responsible for the admission. Even though another diagnosis may be more severe than the principal diagnosis, the principal diagnosis, as defined above, is entered. Entering any other diagnosis may result in incorrect assignment of a Medicare Severity – Diagnosis Related Group (MS-DRG) and an incorrect payment to a hospital under PPS
Other diagnoses codes are required on inpatient claims and are used in determining the appropriate MS-DRG. The provider reports the full codes for up to twenty four additional conditions if they coexisted at the time of admission or developed subsequently, and which had an effect upon the treatment or the length of stay.
The principal diagnosis should not under any circumstances be duplicated as an additional or secondary diagnosis. If the provider reports duplicate diagnoses they are eliminated in Medicare Code Editor (MCE) before GROUPER.
The Admitting Diagnosis Code is required for inpatient hospital claims subject to A/B MAC (A) review. The admitting diagnosis is the condition identified by the physician at the time of the patient’s admission requiring hospitalization. For outpatient bills, the field defined as Patient’s Reason for Visit is not required by Medicare but may be used by providers for nonscheduled visits for outpatient bills.
Outpatient Claim Diagnosis Reporting
For outpatient claims, providers report the full diagnosis code for the diagnosis shown to be chiefly responsible for the outpatient services. For instance, if a patient is seen on an outpatient basis for an evaluation of a symptom (e.g., cough) for which a definitive diagnosis is not made, the symptom is reported. If, during the course of the outpatient evaluation and treatment, a definitive diagnosis is made (e.g., acute bronchitis), the definitive diagnosis is reported. If the patient arrives at the hospital for examination or testing without a referring diagnosis and cannot provide a complaint, symptom, or diagnosis, the hospital reports the encounter code that most accurately reflects the reason for the encounter.
Examples include:
• Z00.00 Encounter for general adult medical examination without abnormal findings
• Z00.01 Encounter for general adult medical examination with abnormal findings
• Z01.10 Encounter for examination of ears and hearing without abnormal findings
• Z01.118 Encounter for examination of ears and hearing with other abnormal findings
For outpatient claims, providers report the full diagnosis codes for up to 24 other diagnoses that coexisted in addition to the diagnosis reported as the principal diagnosis. For instance, if the patient is referred to a hospital for evaluation of hypertension and the medical record also documents diabetes, diabetes is reported as another diagnosis.
