If a Medical POA is established in Maryland can another POA be established in Georgia if the one in Maryland has not been revoked?

If the NEW POA is done in Georgia, and the person currently resides in Georgia, then the newest POA for Healthcare, done in the current state, will supercede the one that was done prior to the current on, and in another state where the person DID reside, but does no longer reside. A new Health Care directive states current wishes, no matter what previous wishes were, no matter what state they were made in. Certain States do not allow certain things that others may allow. So just get the advanced directive papers for the CURRENT STATE and fill them out. All other directives, written before this, will be no good. No matter their State.

Short answer, Yes.

Latrn, two separate documents for two different states would cause confusion as to which one takes precedence.  As Alva explained, POAs' dates of execution take precedence; typically when one is amended, the new document specifically revokes the earlier document.   That's the way I've seen it handled in estate planning firms for which I worked.

What I think you might consider doing is contacting either an estate planning or elder law attorney (after doing research and finding one with experience and knowledge in his/her field that reflects several years of practice), and ask that attorney to prepare one document for both states.   Do research though to find an attorney with whom you're comfortable.  If you need guidance on this and on finding qualified attorneys in this field, post again.

The attorney would either research the second state, or contact an attorney in that state and work together to produce a document valid in both states.

Or, if I misunderstood and the goal is to have the Georgia document take precedence, then a new document should be drawn up and the Maryland one specifically revoked in the new document.  That alleviates any confusion which one prevails.

This support site is great for caregiving advice but when I comes to legal issues I often cringe at what people write. Consult an attorney regarding legal matters.

Power of Attorney for Health care goes according to the LATEST written. The state doesn't matter. It simply states the wishes of the person, and designated the person privvy to private medical information and to make decisions if the person cannot make his own.
That I know of there is no reason to make a new medical directive when one changes states, though there may be things one state has such as "right to die" in Oregon or California, that another doesn't. A Medical Directive doesn't often address this, but may.
When one changes states it is fine to check with a new doctor. But I think an advance directive states one's wishes wherever they reside.

I really don’t think that POAs are state specific. It’s a contract entered into between a person and their chosen representative asking the representative to act in their best interests in making decisions for them should they become unable to make them themselves. These contracts can be for medical or financial decisions or both. I know state laws are different and if the decisions are complicated or the POA has any questions about what to do, it is their responsibility to research the best and legal course of action