What is the difference between a living will and a durable power of attorney for health care decisions?

A durable power of attorney for health care allows someone you trust to direct your health care wishes should you be incapacitated. A living will sets out the medical treatment you are willing to accept or decline should you become incapacitated. California combines both of these into an advance health care directive. Physician Orders for Life-Sustaining Treatment (POLST) supplements advance health care directives. POLST deals with current treatment needs while "advance" health care directives deal with future desires in regards to treatment.

Based on your various posts, I would suggest you consult with an experienced estate planning attorney to draft your estate plan. In California, generally, an Advance Health Care Directive takes the place of a living will.

As Mr. Mubasher wrote, the two documents are complementary - some people just want to appoint ahead of time someone that they trust to make decisions (DPA for Health Care) , some people want make those decision for themselves ahead of time (living will), some end up executing both documents without realizing their purpose. It's entirely a personal choice - and one that can easily be changed later if circumstances or the person's perspective changes.