
Marchman Act Petitions | South Florida
Wondering If a Sibling Can File a Marchman Act Petition?
Robinson Casey limits practice to Marchman Act petitions and guardianship matters for families across South Florida and statewide. Start with a free, confidential first consultation.
By Richard J. Casey III, Esq. · Published October 21, 2026
Short Answer: Can a Sibling or Grandparent File a Marchman Act Petition?
Yes. A sibling or grandparent can file a Marchman Act petition in Florida if they are a relative of the person. Fla. Stat. § 397.68112 lets “any relative” file for an adult.
Watching a brother, sister, or grandchild’s substance use get worse is hard. Many relatives feel they must act fast, often with little time to think. This page explains who may file, what a petition must contain, and where a family member can start. For the wider process, see our Marchman Act guide.
If a brother, sister, or grandparent's drinking or drug use has you worried, you don't have to sort out the legal steps alone. Call Robinson Casey or request a consultation to talk through your family's facts. Talk it through with our team — the first consultation is free, confidential, and carries no obligation.

What the Marchman Act Is and How It Differs from the Baker Act
The Marchman Act is Florida’s court process for substance abuse impairment. The Baker Act is a separate Florida law, and this page covers only the Marchman Act.
A Marchman petition does not commit anyone automatically. It asks a judge to order an assessment and stabilization. In an emergency, the court may enter an ex parte order based on the petition alone. Fla. Stat. § 397.6818 says that order must be carried out while the hearing is pending. If the ex parte order was not executed by the initial hearing date, it is deemed void. However, if the respondent does not appear at the hearing for any reason, including lack of service, and the court reasonably believes the respondent meets this chapter’s commitment criteria and that a substance abuse emergency exists, the court may issue or reissue an ex parte assessment and stabilization order that is valid for 90 days.
Guardianship is a different kind of court case. It asks who makes decisions for a person who cannot manage their own affairs. A Marchman petition asks for help with substance use. Some families face both issues, but the two cases answer different questions.
Who Counts as a Qualifying Petitioner Under the Statute
They are a spouse or legal guardian, any relative, a service provider, and an adult with direct personal knowledge of the person’s substance abuse impairment. A sibling or grandparent falls in the “any relative” group.
For a minor, the list is shorter. A parent, legal guardian, or service provider may file. A sibling or grandparent is not on that minor list.
An adult with direct personal knowledge can also file. That includes a friend or coworker who has seen the person’s use firsthand and knows the person’s prior treatment.
Petitions often require a signed statement that the facts are true. Florida allows a written declaration for that purpose. It must say: “Under penalties of perjury, I declare that I have read the foregoing [document] and that the facts stated in it are true.” Knowingly making a false declaration is a third-degree felony under Fla. Stat. § 92.525. Fla. Stat. § 92.525 reads: “(2) A written declaration means the following statement: “Under penalties of perjury, I declare that I have read the foregoing [document] and that the facts stated in it are true,” followed by the signature of the person making the declaration, except when a verification on information or belief is permitted by law, in which case the words “to the best of my knowledge and belief” may be added.”
What a Sibling or Grandparent Petitioner Needs to Show
A petition must state specific facts, not general worry. Fla. Stat. § 397.68141 requires the respondent’s name, the petitioner’s name, and the relationship between them. It also requires the respondent’s attorney if known, and the facts that show a need for services.
The facts must explain why you believe the person is impaired. They must also explain why you believe the person has lost power of self-control over substance use. Then the petition must show either physical harm or a refusal to get care based on impaired judgment.
Write down what you saw and heard yourself. If you learned something from someone else, note who told you. Firsthand facts are clearer and easier to stand behind.
A petition may include a professional’s report from within 30 days before filing. If the person was never assessed or refused an evaluation, the petition must say so.
The petitioner carries the burden of proof. The Fifth District Court of Appeal reversed an order where the court questioned the only witness after the petitioner was absent (J.C. v. State). At a hearing, the court must find the conditions proven by clear and convincing evidence before it can order up to 90 days of treatment (Fla. Stat. § 397.697).
Where a Grandparent or Sibling Fits When a Guardian or Parent Is Involved
A sibling or grandparent can still be a relative with the right to file. That remains true when a parent, spouse, or guardian already has a role.
The statute lists several groups who may file. If the adult already has a legal guardian, that guardian is also on the list.
The respondent has a right to counsel at every stage of the case, which the respondent may waive only if present and the court finds the waiver knowing, intelligent, and voluntary (Fla. Stat. § 397.681). Copies of the petition and notice of the hearing must also be provided to the respondent, the respondent’s parent, guardian, or legal custodian if the respondent is a minor, the respondent’s attorney if known, the petitioner, the respondent’s spouse or guardian if applicable, and any other persons the court directs; if the respondent is a minor, the copy of the petition and notice of the hearing must be personally delivered to the respondent (Fla. Stat. § 397.68151).
Robinson Casey’s practice also covers guardianship matters, including emergency temporary, limited, plenary, and mental health guardianship. Those cases answer a different question than a Marchman petition.
Practical Steps for a Relative Who Is Considering a Petition
Start by writing down what you saw, when it happened, and who else was there. Keep dates and details accurate. Do not add facts you cannot support.
A petition goes to the clerk of the court in the county where the person is located (Fla. Stat. § 397.681). The Fifth District treated filing in the wrong county as a venue defect, not a lack of jurisdiction (J.P. v. J.N.). For local detail, see our Miami-Dade page and our guide on which court hears a petition.
The court must schedule a hearing within 10 court working days unless a continuance is granted (Fla. Stat. § 397.68151).
Can a grandparent file a Marchman Act petition in Florida?
Yes. A grandparent is a relative, and the statute lets any relative file for an adult.
Can a sibling file for an adult brother or sister?
Yes. Your specific facts still matter.
Is there a filing fee?
No. The clerk may not charge a fee for filing a petition under this section.
Not sure what your next step is?
Talk it through with our team — the first consultation is free, confidential, and carries no obligation.

Talk Through Your Family’s Situation with Robinson Casey
If you are a sibling or grandparent trying to decide what to do, you don’t have to settle that alone. Robinson Casey focuses on Marchman Act petitions and guardianship matters for families in South Florida and statewide.
You may be the one carrying the worry, the late-night calls, and the question of whether a court will act. Call (561) 849-4149 or request a consultation to talk through your facts.
The first consultation is free, confidential, and comes with no obligation to continue.
Why Families Start with Robinson Casey
Focused Practice
Robinson Casey focuses on Marchman Act petitions and guardianship matters, so the conversation stays centered on the issues families face.
Free, Confidential Consultation
Your first consultation is free and confidential, with no obligation to continue.
Organized Preparation
Bring the facts of your sibling's situation and any court or treatment history you have, so the discussion starts with clear information.
Direct Access
Call (561) 849-4149 to speak with our team about your family's situation.
If Someone Is in Immediate Danger
If your sibling is at immediate risk of harm, call 911 first. Then contact our office to discuss the options that may apply to your family's circumstances.
Questions Siblings Often Ask
Does the Law Allow a Sibling to Petition?
Florida law addresses who may file a Marchman Act petition. How it applies depends on the facts of your family's situation, so review them with a lawyer.
What Information Helps?
Names, addresses, a description of recent events, and any prior treatment or court history can help frame the discussion during your consultation.
Who Else May Be Involved?
Other family members, treating professionals, and the court may take part in the process. Our team can explain how each step may affect your family.
