Modifier AI is used identify the principal physician of record during an inpatient admission. This modifier should only be used by the admitting or attending physician overseeing the patient’s care during a hospital or nursing facility admission.

The attending physician shall append modifier AI to the initial hospital care or nursing facility code only, subsequent days do not require use of the AI modifier.

This is an informational only modifier and does not affect claim payment. Claims without the AI modifier represents specialty care.

Appropriate use

• Admitting physician appends to the initial inpatient hospital care evaluation and management service (99221-99223).
• Admitting physician appends to the initial nursing facility evaluation and management service (99304-99306).
• Append after payment modifiers.

Inappropriate use

• Reported by any physician other than attending or admitting physician who oversees the patient’s care during the hospital, or nursing home admission.
• Reported on procedures codes other than 99221-99223 and 99304-99306.

Reference

• CMS IOM Pub. 100-04, Medicare Claims Processing Manual, Chapter 12, Sections 30.6.9.1-F & G, 30.6.10 and 30.6.13 A