What is a a doctors office allowed to disclose to a patient's employer?

Off hand, no the doctors office isn’t suppose to reveal anything. I don’t think they can even say that you are one of their patients unless you have given them permission to do so. The exception to this is your insurance company. The doctor would have to tell them.

I am sure that would be illegal. Your doctor’s office isn’t even supposed to reveal that information to your spouse – let alone your employer.

No, HIPAA would prohibit a healthcare provider from disclosing that you even received services from them, much less on what dates. From the HIPAA website:

“The Privacy Rule protects all “individually identifiable health information” held or transmitted by a covered entity or its business associate, in any form or media, whether electronic, paper, or oral. The Privacy Rule calls this information “protected health information (PHI).“12

“Individually identifiable health information” is information, including demographic data, that relates to:

the individual’s past, present or future physical or mental health or condition,
the provision of health care to the individual, or
the past, present, or future payment for the provision of health care to the individual”

They can only reveal that information if you give the Doctor’s Office express written permission to do so.

The doctor is not even supposed to reveal you are patient, let alone when you were there.

Your employer should know better than to even call. They are not entitled to any information from your doctor.
The only interactions between your employer and your health care providers would be the reception of excused notes, if you were under your doctor’s care. And those only say that you were under their care for certain dates, no details.

What everyone else has said is true, with an exception. If you are being seen due to something that happened at work (such as a workman’s comp issue), your doctor can share information regarding the workman’s comp issue with your employer.

Also, I think there are exceptions with FMLA as well, but I’m not 100% sure. With this, I mean that while you are getting the FMLA stuff set up, your employer can be in contact with your doctor in order to make sure that have things handled correctly.

In either case (workman’s comp or FMLA) you in essence give consent for them to communicate when setting things up.

I believe @Seaofclouds is correct, except I think that in order for even a Workmen’s Comp doctor to provide information to your employer’s insurance company, you would have to sign something saying you give permission. For FMLA, the forms are filled out by the doctor and there’s probably a line for you to sign, should the employer need to contact the doctor for any additional information.

I gave this a GQ because I had been curious myself, in the event I provide a doctor’s note to my employer for being out sick, if the employer would be able to obtain additional information from the doctor regarding my treatment. When I get a doctor’s note, it usually either states something very vague as the reason for my visit, such as “medical condition” or it says something almost as vague, such as “respiratory ailment.”

No, doc offices are not allowed to release that info without your permission. You can give us verbal permission to write a note stating you were at our office on such and such date at such and such time. If you require that this note include the reason for the visit, you would be asked to fill out and sign a Release of Medical Records form.

Source: 5 years in medical office administration.

Nothing without your permission. And if they do you can report them for a HIPAA violation