Can my employer...?

Yes he can but they are not allowed to give out any information regarding your medical treatment, including whether or not you had blood work done.

If you used the blood work as an excuse to get out of work, then they can verify it, yes.

The medical provider can't disclose they know who you are without your consent.

If you claimed the blood work as a reason to miss work, you can be FIRED for not providing proof.

Yes, he can call, and it can be verified that you had blood work done. HIPAA laws, however, prevent health care professionals to tell anyone of the results of those blood tests.

No, they will not give him any information about you, that is just for you.If you wish you can ask them to give you a letter to say that you were there that day, he has no business to know any more.

Yes, he can call and ask. But due to HIPAA, they can't tell him.

If you took time off work to get the test done or if the employer is paying for the blood work then of course they can verify if you actually had it done.

The facility won't tell him.

He can call and ask, but without a waiver from you, they should not give that info.

He can call and ask, but the facility should not provide that info.