Viva Engage, formerly Yammer, is a Microsoft product. HIPAA is not directly addressed on the product page, but the Microsoft Learn website provides an overview of security and compliance for the Viva Engage platform.
According to Microsoft Learn, Viva Engage is Tier-C compliant in the Microsoft 365 Compliance Framework, which includes HIPAA. This feature is not a part of Viva Engage Basic. It’s only offered as a part of Viva Engage Enterprise.