Laws can still prevent someone with your Advance Care Directive from accessing medical records.
It seems illogical that the person who is named as your agent under an Advanced Care Directive can't gain access to your health care records. However, that can sometimes be the case, according to the Monterey Herald in “Senior Advocate: Can my health care agent help me now?”
The Advance Health Care Directive isn't the document that gives someone access to all of your medical information. It is usually the document that gives your named agent the power to make decisions about end-of-life or life-saving decisions. It's the document that is used if a decision must be made about taking a person off of a respirator or a heart machine.
If you want to give someone the ability to run health-related errands for you or speak with your healthcare providers, it is possible to have an Advanced Health Care Directive prepared, so it becomes immediately effective, regardless of your capacity. This can be used to give a spouse the ability to have access to all your medical records and information.
If you are ill and want to have your spouse involved in your medical care, even if you are not incapacitated, the “effective immediately” option will let your spouse act on your behalf. You won't have to wait for a physician to state that you are incapacitated, before an Advanced Directive can take effect.
Since an Advance Directive usually names an alternate agent, you can have the document prepared so your spouse is able to be effective anytime, but the alternate agent can be limited to when your spouse is not able to help, and you are unable to speak for yourself because you have become incapacitated.
Keep in mind that the Advance Directive, whether effective immediately or only upon incapacity, has nothing to do with your finances. That requires a different document, or documents, depending upon your estate plan and your unique situation.
An estate planning attorney can advise you on creating and estate plan that fits your unique circumstances and includes the documents you need.
Reference: Monterey Herald (Dec. 22, 2018) “Senior Advocate: Can my health care agent help me now?”