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Texas Medical Power of Attorney vs. Advance Directive: Understanding Texas Health and Safety Code Chapter 166
July 31, 2026 at 10:30 PM
by David C. Barsalou, Esq.
Attorney explaining the difference between a Texas Medical Power of Attorney and an Advance Directive during an estate planning consultation. Medical documents, the Texas Health and Safety Code Chapter 166, and healthcare planning materials are displayed on a desk, illustrating advance healthcare directives under Texas law.

Many Texans assume that a Medical Power of Attorney and a Living Will are the same document. They are not.

Texas law recognizes several different healthcare planning documents, each serving a different legal purpose. Understanding these documents before a medical emergency can help ensure that your wishes are followed and reduce conflict among family members.

What Is a Medical Power of Attorney?

A Medical Power of Attorney (MPOA) allows you (the principal) to appoint another person (the agent) to make healthcare decisions if you become unable to make those decisions yourself.

Importantly, your agent does not automatically gain authority simply because you signed the document. The authority generally becomes effective only when your attending physician certifies that you lack the capacity to make your own medical decisions.

This is an important distinction because competent adults always retain the right to make their own healthcare decisions.

What Is an Advance Directive?

An Advance Directive (sometimes called a "Living Will") serves a different purpose.

Rather than appointing another decision-maker, an advance directive tells healthcare providers your own wishes regarding life-sustaining treatment if you have a terminal or irreversible condition.

Texas Health and Safety Code § 166.033 provides:

"A competent adult may at any time execute a written directive."

That simple sentence authorizes Texans to document their treatment preferences before they become incapacitated.

Different Documents for Different Purposes

Many estate plans include multiple healthcare documents because each addresses a different issue.

Common examples include:

  • Medical Power of Attorney
  • Directive to Physicians (Living Will)
  • HIPAA medical information authorization
  • Out-of-Hospital Do-Not-Resuscitate Order (when appropriate)

Each serves a unique legal function.

Why Both Documents Matter

Imagine someone becomes unconscious following a serious accident.

A Medical Power of Attorney allows an appointed individual to communicate with physicians and make healthcare decisions when appropriate.

An Advance Directive tells physicians what the patient wanted regarding life-sustaining treatment if the statutory conditions are met.

These documents complement one another rather than replace one another.

Can Family Members Decide Without These Documents?

Sometimes.

Texas law provides default rules regarding surrogate decision-makers in certain situations. However, relying solely upon statutory default decision-makers can create uncertainty, especially if family members disagree.

Executing proper healthcare planning documents often reduces confusion and can make difficult situations somewhat easier for loved ones.

Can You Change Your Mind?

Yes.

Texas law generally allows a competent adult to revoke or amend these documents while competent.

Estate planning documents should also be reviewed after significant life events such as:

  • Marriage
  • Divorce
  • Birth of children
  • Death of a previously named agent
  • Significant changes in health

Common Mistakes

Some of the most common problems include:

  • Naming an unavailable or unsuitable agent.
  • Forgetting to update documents after a divorce.
  • Assuming a spouse automatically has unlimited authority.
  • Failing to inform family members that the documents exist.
  • Confusing a Financial Power of Attorney with a Medical Power of Attorney.

Estate Planning Is About More Than Wills

Many people think estate planning begins and ends with a Last Will and Testament.

In reality, incapacity planning is just as important. A comprehensive estate plan often includes documents governing financial decisions, healthcare decisions, and end-of-life wishes.

Preparing these documents before they are needed can help avoid unnecessary disputes and ensure your wishes are more likely to be respected.

Contact a Texas Estate Planning Attorney

If you need assistance preparing a Medical Power of Attorney, Advance Directive, or other estate planning documents, consulting with an experienced Texas attorney can help ensure that your documents comply with Texas law and reflect your individual wishes.

At David C. Barsalou, Attorney at Law, PLLC, we help clients navigate business, family, tax, estate planning, and real estate matters ranging from document drafting to litigation with clarity and confidence. If you’d like guidance on your situation, schedule a consultation today. Call us at (713) 397-4678, email barsalou.law@gmail.com, or reach us through our Contact Page. We’re here to help you take the next step.