Quick answer (plain English)

If your parents are alive, you generally cannot force a sibling to turn over private estate-planning documents unless the sibling is a fiduciary (for example, a trustee) or your parents have given you a legal right (such as naming you a beneficiary, executor, or co-trustee, or giving you a power of attorney). If a parent has died, a valid last will typically must be submitted to probate and becomes part of the public court record; if a sibling is a trustee, executor, or personal representative and refuses to provide required notices or copies, you can ask the court to compel production or to enforce fiduciary duties under Missouri law.

Detailed answer — what Missouri law and procedure generally allow

1. Are the documents private or part of a public probate file?

If a parent is alive: estate plans (wills, trusts, powers of attorney, advance directives) are private documents. A sibling who simply holds a copy does not automatically have to give it to you unless the document or law gives you a right to it. If the parent named the sibling as trustee, the trustee has obligations to beneficiaries under Missouri trust law; beneficiaries often have the right to receive copies or information about the trust. See Missouri’s trust laws for beneficiaries’ information rights: Missouri Revised Statutes, Chapter 456 (Uniform Trust Code) (revisor.mo.gov – Chapter 456).

If a parent has died: a last will and testament is usually filed with the probate court in the decedent’s county to begin administration. Once filed, the will becomes part of the court record and is accessible through the probate court. If a sibling is the person in possession of the will and refuses to deliver it to the court, interested persons can petition the probate court to require filing and to enforce duties. See Missouri statutes on wills and probate (Chapter 474): revisor.mo.gov – Chapter 474.

2. If the parents are alive, what options do you have?

• Ask the parents directly. The most direct route is to request that your parents provide copies or tell the sibling to produce them. If your parents want privacy, you may have limited options.
• Check whether you are a named beneficiary, successor trustee, or have a power of attorney. Those roles can create legal rights to information or documents.
• If the sibling is a trustee: beneficiaries typically can request trust information. Under Missouri’s trust laws beneficiaries usually may obtain a copy of the trust instrument and accountings in many situations (see Chapter 456: Uniform Trust Code). If the trustee refuses, beneficiaries can petition the court to compel production and to remove or sanction a trustee for breach of duty.
• Consider mediation or a demand letter from an attorney if communication has broken down. A professional letter can prompt cooperation without immediate court action.

3. If a parent is deceased, what can you do?

• If you suspect a will exists: check with the probate division of the circuit court in the county where the parent lived. If the sibling is withholding a will, you can ask the court to require the sibling to file it. If the sibling wrongfully conceals or destroys a will, you may have remedies in probate court and possibly civil claims for wrongful concealment.
• If the sibling is the personal representative or executor and is refusing to disclose estate information: Missouri probate law imposes duties on personal representatives. Interested persons can petition the probate court for accounting, production of documents, or removal of the personal representative for misconduct.
• If the sibling is trustee and the trust covers assets after death: beneficiaries can request accountings and copies of the trust from the trustee and can petition the appropriate court for relief under trust law.

4. Court actions commonly used to get documents

• Petition in probate court to compel filing of a will or to compel production from a personal representative.
• Petition for an accounting or to compel disclosure from a trustee under Missouri trust law.
• Lawsuit for breach of fiduciary duty, conversion, or concealment if a fiduciary intentionally withholds or destroys estate documents.
• In limited circumstances, filing an action for declaratory relief or injunctive relief to prevent destruction or to force turnover of documents.

5. Practical considerations and likely outcomes

• Courts balance privacy interests with beneficiaries’ rights. If the parents are alive and oppose disclosure, courts are unlikely to force a sibling to hand over private documents unless a statute or court order gives you that right.
• If a fiduciary duty exists (trustee, executor, agent under a power of attorney), Missouri law gives stronger tools to obtain documents and to hold the fiduciary accountable.
• Cost and time: litigation can be expensive and slow. Sometimes a targeted demand letter, neutral mediator, or approaching the parents directly will resolve the issue faster.

Helpful Hints — practical next steps

• Start by talking to your parents (if they are able and willing). Ask them if they want to provide copies to you or instruct the sibling to deliver them.
• Document your requests. Keep copies of emails, letters, text messages, dates and times of calls. A clear record helps if you later go to court.
• Confirm roles. Find out whether the sibling is an executor, trustee, or agent under a power of attorney—those roles create legal duties.
• Check public records. If a parent has died, search the probate court records in the county where the parent lived to see whether a will has been filed and a personal representative appointed.
• Send a formal written demand. If informal requests fail, a written demand (preferably via certified mail) telling the sibling what you want and why can be effective and creates a record.
• Consider a lawyer’s demand letter. An attorney can send a letter explaining the legal obligations and possible court remedies—this often prompts disclosure without filing suit.
• If you are a beneficiary or named in the documents, act promptly. Courts sometimes limit the time to file certain challenges or claims once you learn of the document’s existence.
• Weigh alternatives to litigation. Mediation, family meetings, or neutral third-party review of documents may resolve disputes quicker and at lower cost.
• Choose an attorney experienced in Missouri probate and trust law. They can identify the most efficient remedy and cite the specific Missouri statutes and court procedures that apply to your situation.