Is Fire Vault HIPAA compliant?

File vault is more than sufficient, actually. So long as physical access is controlled. The data doesn't actually have to be encrypted locally to meet HIPAA standards. HIPAA only requires encryption for data in transit via a public network.

The HIPAA regulations are incredibly vague and at the same time, very complex. As an IT manager in health-care, I've learned more about HIPAA than I ever wanted to know.

FileVault only encrypts the file system. Any HIPAA protected information would still need to be encrypted on the file system to meet HIPAA compliance requirements of controlling who on the computer can access the information.

This Apple document describes what File Vault encrypts: OS X: About FileVault 2 - Apple Support.

However, it only works on the boot drive. So if your patient data is on EHDS then you would need to look for a 3rd party disk encryption scheme.

This is from that document:

FileVault 2 uses full disk, XTS-AES 128 encryption to help keep your data secure. Using FileVault 2, you can encrypt the contents of your entire drive.

No. iCloud is not HIPAA compliant. The only HIPAA compliant cloud service provider is Microsoft. Storage and mail systems included with office 365 (business, not personal) and Azure are HIPAA compliant and Microsoft will sign the necessary paperwork to certify that.