Not sure if this question is appropriate for this topic.
There is a lot of documentation stating that Google will sign a BAA for their services but it is very difficult to find the place to actually sign it. After a few searches I was able to find how to sign a BAA for AWS. I'd prefer to use GCP since it's the platform I'm familiar with but I may need to switch to AWS if I can't sign a BAA with Google.
This page details Google Cloud HIPAA Compliance. You will need to contact your account manager to receive a BAA. Also required is that you do not use / disable any products not covered by the BAA.
https://cloud.google.com/security/compliance/hipaa/
[Update Nov-26-2018]
If you have setup G Suite:
Login to G Suite as an admin.
Go to Company profile -> Profile -> Security and Privacy Additional Terms.
You will find G Suite/Cloud Identity HIPAA Business Associate Amendment.