Can the employer require me to state "the nature of illness" when calling in sick? Can I be required to specifically list the nature of my illness for payroll paperwork? What role does HIPAA play in reporting sick usage? I am confused and have heard different information recently.

Sorry if this is duplicate, I couldnt find the information.

Your employer can require you to provide sufficient information to know whether or not FMLA applies or might apply. That does not necessarily mean the specific diagnosis or prognosis, but they do have to know enough to establish what protections are available to you.

In the employment arena, the only information that is HIPAA protected is that which is obtained from the group health insurance plan, and only that if it is a self-insured plan. HIPAA does not come into play when reporting in sick.