Does P03.819 require prior authorization?

No, P03.819 does not require prior authorization (high confidence). Covered without prior authorization.

`P03.819`, Newborn affected by abnormality in fetal (intrauterine) heart rate or rhythm, unspecified as to time of onset

ICD-10-CM

No Prior Auth Required

Covered without prior authorization (high confidence)

The article provides billing/coding guidance that complements LCD L39400; use the documentation, prior authorization, and claim submission requirements specified in LCD L39400 and the local contractor's instructions.
Note on Documentation Requirements: Physicians are reminded to bill the findings of the diagnostic test as the primary indication rather than the referring physician’s diagnosis, as indicated by Medicare’s Diagnostic Imaging Billing guidelines.
These guidelines are available in the Medicare Claims Processing Manual, Chapter 13 - Radiology Services and Other Diagnostic Procedures (revised November 2016).

No specific clinical indications are listed in this article; follow the Local Coverage Determination (LCD) L39400 for indications for magnesium testing or services.
During excision of left atrial mass;
Evaluation of angina;
Evaluation of aortic diseases;
Evaluation of aortocoronary bypass grafts;
Evaluation of atrial fibrillation/flutter;

AETNA-CPB-0008, Color-Flow Doppler Echocardiography and Myocardial Strain Imaging

A59186, Billing and Coding: Magnesium