Federal privacy law restricts who a healthcare provider may share your medical information with. A HIPAA release is the authorization that lifts that restriction for people you name. Without it, a hospital can decline to tell your adult child what is happening to you, and that refusal comes at exactly the moment your family most needs to understand your situation.
It is quietly the document that makes other documents work. A healthcare agent who cannot obtain your diagnosis, test results, or prognosis is being asked to make decisions blind. A springing power of attorney that activates on a physician's certification of incapacity requires someone to be able to request that assessment. Both stall on the same wall, and a release is what removes it.
Naming people broadly is usually the right instinct here. The obvious appointees are your healthcare agent and your successor, but consider anyone likely to be at a hospital while other family members are travelling. A release grants access to information; it does not grant authority to decide anything, so including someone carries far less risk than excluding them.
Providers commonly maintain their own authorization forms, and a hospital may prefer its own over a general one you bring. Signing the forms your regular physicians and any facility you use routinely provide, alongside a standalone release kept with your estate documents, reduces the chance of an argument at an admissions desk. Requirements around the form and its handling can also vary by state.