Missouri: Health Care Power of Attorney Requirements

Missouri splits the two advance-planning documents that many states combine. The
document that names someone to make your medical decisions — the durable power
of attorney for health care — is governed by its own statute, the Durable Power
of Attorney for Health Care Act at Mo. Rev. Stat. §§ 404.800–404.865. The separate
"living will" (a statement about life-support if you are terminally ill) lives in a
different chapter. This page is about the first document: naming a health care
agent (the statute calls the agent your "attorney in fact"). Widely used forms,
including the Missouri Bar's, print both documents together, but their signing
rules are not the same — and that difference trips people up.

Requirements one by one

Governing law and document

The Act at § 404.800 provides that "[s]ections 404.800 to 404.865 may be cited
as the 'Durable Power of Attorney for Health Care Act.'" Unlike states that publish
one official fill-in-the-blank directive, Missouri's Act does not prescribe a
mandatory statutory form; you may use any document that meets the execution rules
below. The Missouri Bar and the state Attorney General publish free forms that
comply with the Act, but the form itself is not what the law requires — the
formalities are.

Who can sign

The document is executed by you, the principal (the Act calls you the "patient").
Under § 404.705, to be durable — to keep working after you lose capacity, which
is the entire point — the document must be "denominated a 'Durable Power of
Attorney,'" must contain durability language stating in substance that your agent's
authority "shall not terminate if I become disabled or incapacitated," and must be
"subscribed by the principal, and dated." The Act does not set a separate age or
capacity test in its text; a competent adult signs it under Missouri's general law.

Witnesses or notary

This is the step to get right. Section 404.705(3) requires that the durable power
of attorney be "subscribed by the principal, and dated and acknowledged in the
manner prescribed by law for conveyances of real estate." Acknowledging a
document "in the manner prescribed for conveyances of real estate" means signing it
before a notary public — the same way you would a deed. So Missouri requires
notarization for the health care agent appointment, and it gives you no
two-witness alternative.

The confusion comes from the living will. If you also complete the separate living
will (the treatment-only part), that document requires two witnesses. On a
combined form you may see both a notary block and a witness block, which makes it
look like you need witnesses for everything. You do not — the witnesses are there
for the living will; the notary is what validates the part that names your
agent.

Who can't witness or serve

Because Missouri uses a notary rather than witnesses for the agent appointment,
there is no list of disqualified witnesses. There is a limit on who may serve as
your agent, though. Under § 404.815, "an attending physician or an employee of
the attending physician, or an owner, operator or employee of a health care
facility in which the patient is a resident, shall not serve as an attorney in
fact" — unless that person is related to you "within the second degree" (a parent,
child, sibling, grandparent, or grandchild), or belongs to the same religious
community. So you generally cannot name your treating doctor or the staff of your
nursing home as your agent unless they are close family.

When the agent can act

By default the power is springing — it sits dormant until you cannot make your
own decisions. Section 404.825 provides that "[u]nless the patient expressly
authorizes otherwise in the power of attorney, the powers and duties of the
attorney in fact to make health care decisions shall commence upon a certification
by two licensed physicians ... that the patient is incapacitated," and cease on
a certification that you have recovered. One of the two may be your attending
physician. You can change this in the document — the Missouri Bar form, for example,
lets you check a box for one physician instead of two — but "certification of
incapacity by at least one physician is required" no matter what.

Agent's powers and limits

Once the power is in effect, your agent makes the health care decisions you could
make yourself. Section 404.822 directs the agent, "[i]n making any health care
decision," to "seek and consider information concerning the patient's medical
diagnosis, the patient's prognosis and the benefits and burdens of the treatment."
The Act's express limits are narrow and both concern feeding tubes. Under
§ 404.820(1), authority "to direct a health care provider to withhold or
withdraw artificially supplied nutrition and hydration" must be "specifically
grant[ed]" in the document — a general grant of authority is not enough. And under
§ 404.820(2), "no attorney in fact may, with the intent of causing the death of the
patient, authorize the withdrawal of nutrition or hydration which the patient may
ingest through natural means."

How to revoke

Missouri makes revocation easy. Under § 404.850, you "may [revoke] at any time
and in any manner by which [you are] able to communicate the intent to revoke," and
the revocation "shall be effective upon communication ... to the attorney in fact or
to the attending physician or health care provider." You do not need a signed
writing or a notary to revoke. Signing a new valid health care POA also revokes any
earlier one unless the new one says otherwise (§ 404.850(3)). Note that the Act does
not automatically cancel a spouse-agent's authority if you later divorce — if
you named your spouse and your marriage ends, sign a new document to change your
agent.

Out-of-state directives

The Act has no clause squarely saying "a directive from another state is honored
here." But the durable-power definition in § 404.703(4) does most of that work:
a document counts as a durable power of attorney if it is durable under Missouri's
rule or "under the laws of ... the place where executed" or "the place of the
residence of the principal when executed." So a durable health care POA you signed
in another state, valid where you signed it, carries its durability into Missouri.

What trips people up

• Notarize it — witnesses are not a substitute. The single most common mistake
  is treating two witnesses as enough. For the agent appointment, Missouri requires
  a notary and offers no witness-only path (§ 404.705(3)). If your form was only
  witnessed, the part naming your agent may not be valid.
• The witness lines on a combined form are for the living will. Seeing both a
  witness block and a notary block does not mean you need both for the agent
  appointment. The witnesses satisfy the separate living will; the notary validates
  the health care POA.
• Two physicians, by default, decide when your agent takes over. Unless you
  choose otherwise in the document, your agent cannot act until two doctors certify
  that you are incapacitated (§ 404.825). If you want a faster, one-physician
  trigger, you must say so in the document.
• Feeding-tube authority is not automatic. Even a broadly worded document does
  not let your agent stop artificial nutrition and hydration unless you granted that
  power specifically (§ 404.820(1)). If that decision matters to you, address it
  expressly.
• Divorce does not undo it. Missouri's Act has no automatic revocation on
  divorce. A former spouse you named stays your agent until you revoke and sign a
  new document.

Common questions

Does my Missouri health care power of attorney have to be notarized?
Yes. The part that names your agent must be acknowledged before a notary, the same
way a deed is (§ 404.705(3)). There is no two-witness alternative for the agent
appointment.

Can I name my daughter as my agent even though she is a nurse at my nursing
home?
Yes. The bar on facility staff serving as agent does not apply to someone related to
you within the second degree — a daughter qualifies (§ 404.815).

Can my agent decide to stop tube feeding?
Only if you specifically gave that power in the document. A general grant of
authority does not include withholding or withdrawing artificially supplied
nutrition and hydration (§ 404.820(1)).

Will the health care directive I signed in another state work in Missouri?
Its durability carries over: a power that is durable under the law of the state
where you signed it, or where you lived when you signed it, is a durable power of
attorney in Missouri (§ 404.703(4)).

Statutes and sources

• Mo. Rev. Stat. § 404.800 — short title, "Durable Power of Attorney for Health
  Care Act."
  https://revisor.mo.gov/main/OneSection.aspx?section=404.800 (accessed 2026-07-16)
• Mo. Rev. Stat. § 404.705 — durability requirements; the document must be
  subscribed, dated, and "acknowledged in the manner prescribed by law for
  conveyances of real estate" (notarized).
  https://revisor.mo.gov/main/OneSection.aspx?section=404.705 (accessed 2026-07-16)
• Mo. Rev. Stat. § 404.703 — definitions, including a durable power of attorney's
  durability under the law of the place executed or of the principal's residence.
  https://revisor.mo.gov/main/OneSection.aspx?section=404.703 (accessed 2026-07-16)
• Mo. Rev. Stat. § 404.815 — physician and facility staff barred as agent unless
  related within the second degree or in the same religious community.
  https://revisor.mo.gov/main/OneSection.aspx?section=404.815 (accessed 2026-07-16)
• Mo. Rev. Stat. § 404.825 — springing effect; two-physician certification of
  incapacity, at least one always required.
  https://revisor.mo.gov/main/OneSection.aspx?section=404.825 (accessed 2026-07-16)
• Mo. Rev. Stat. § 404.822 — agent must consider the patient's diagnosis,
  prognosis, and the benefits and burdens of treatment.
  https://revisor.mo.gov/main/OneSection.aspx?section=404.822 (accessed 2026-07-16)
• Mo. Rev. Stat. § 404.820 — nutrition and hydration limits: specific grant
  required; no death-intended withdrawal of naturally ingested nutrition/hydration.
  https://revisor.mo.gov/main/OneSection.aspx?section=404.820 (accessed 2026-07-16)
• Mo. Rev. Stat. § 404.850 — revocation at any time in any manner communicating
  intent; a later POA revokes a prior one.
  https://revisor.mo.gov/main/OneSection.aspx?section=404.850 (accessed 2026-07-16)