Watch: What is HIPAA, and what does it cover?

Earlier this month, a federal regulator launched a probe into a partnership that allowed Google (GOOGL) to collect millions of patient records from the nonprofit hospital chain Ascension.

At the crux of the investigation: whether the companies adhered to HIPAA, or the Health Insurance Portability and Accountability Act. The federal law governs how doctors, hospitals, and researchers can use and share personal health information — and when they have to tell patients they are doing so.

Google and Ascension have both said the initiative — code-named “Project Nightingale” — followed HIPAA.

But what kind of information does the law actually cover, and who does it apply to? We break it down in the latest episode of “The Facts, STAT!”

WATCH the video here