Custody Letter from a Treating Therapist: Template & Role Boundaries

What Is a Custody Letter from a Treating Therapist?

A custody letter is a document a treating mental health clinician writes, at a client's request, for use in a child custody or parenting-time proceeding. It typically describes the client's participation in treatment, the clinician's direct observations of the client, and the client's clinical progress. It is submitted to the family court, the client's attorney, or a guardian ad litem as one piece of information among many the court will consider.

It is essential to be precise about what this letter is not. A custody letter from a treating therapist is not a custody evaluation, and it must never contain a custody recommendation. A custody evaluation is a forensic product prepared by a neutral, court-appointed or stipulated evaluator who interviews both parents, observes parent-child interactions, contacts collateral sources, reviews records, and usually administers psychological testing before offering opinions relevant to the best interests of the child. If that is the document you need to write — because you have been appointed as an evaluator — see our guide to the custody evaluation report, which covers the forensic role in depth.

This page covers the other side of that boundary: what a treating therapist can appropriately provide when a client in a custody case asks for "a letter for court." Written well, such a letter is factual, narrow, and explicitly bounded. Written badly — with opinions about parenting capacity, the other parent, or where the children should live — it invites ethics complaints, licensing board scrutiny, devastating cross-examination, and real harm to the client it was meant to help.

The Critical Distinction: Treating Therapist vs. Custody Evaluator

The single most important concept on this page is the incompatibility of the therapeutic and forensic roles in custody matters. The APA Guidelines for Child Custody Evaluations in Family Law Proceedings, the APA Specialty Guidelines for Forensic Psychology, and the AFCC Model Standards of Practice all draw this line clearly, and it exists for structural reasons, not merely traditional ones.

Different data. The evaluator gathers data from every relevant party and source. You, as a treating therapist, have your client's self-report and your in-session observations of one person. You have never met the other parent. Everything you "know" about the marriage, the separation, and the other household arrived filtered through your client's perspective — which is exactly what a therapeutic frame is supposed to contain, and exactly what a forensic opinion cannot rest on.

Different alliance. Therapy works partly because the therapist is reliably on the client's side. That alliance is a feature in treatment and a disqualifying bias in evaluation. Opposing counsel knows this, and any custody opinion from a treating therapist will be attacked on precisely this ground — usually successfully.

Different obligations. The evaluator's duty runs to the court and the child's best interests. Your duty runs to your client's welfare. When a therapist starts producing forensic opinions, both duties are compromised: the court receives a biased opinion, and the client's therapy becomes an instrument of litigation, which changes what the client will safely say in session.

Different consequences for the relationship. Once you have testified or written advocacy for a client's custody position, you have taken a side in the most consequential dispute of their life. If the case goes badly, or if what you wrote was less glowing than the client hoped, the treatment relationship rarely survives intact.

The practical rule that follows: a treating therapist may serve as a fact witness about the treatment they provided, but not as an expert on custody. Your letter should read like the testimony of a careful fact witness — dates, observations, data — with an explicit statement of scope.

When You Need It

• When a client involved in a custody or parenting-time dispute asks you to document their engagement and progress in therapy
• When a client's attorney requests documentation that the client has followed through on treatment referenced in the proceedings
• When a client has completed court-ordered treatment (for example, anger management, substance use treatment, or co-parenting counseling) and needs verification for the family court
• When a guardian ad litem or parenting coordinator requests information about your client's treatment, with proper authorization
• When a client seeks to demonstrate stability and treatment compliance in a modification or reunification context
• When a prior clinical concern raised in the litigation (for example, an untreated condition) has since been addressed in treatment and the client wants that documented

In every one of these scenarios, the letter documents your client's treatment — never the custody question itself.

Key Components

Provider credentials and treatment relationship. Your name, degree, license type and number, and the nature of the treatment: individual therapy, co-parenting counseling, or family therapy; start date; session frequency; total sessions to date.

Scope and limitations statement. The most important paragraph in the letter. State explicitly that you write as the client's treating clinician; that your observations arise from the therapeutic relationship; that you have not interviewed, evaluated, or formed opinions about any other party, including the children (unless they are your client) and the other parent; that the letter is not a custody evaluation; and that you offer no opinion on custody, parenting time, or the best interests of the children.

Treatment engagement. Why the client sought (or was referred to) treatment, described at the level of generality the client has authorized; attendance record; consistency; completion of between-session work; whether any court-ordered requirement has been met.

Clinical observations of your client. Directly observed, behaviorally described, and jargon-free: emotional presentation across sessions, skills the client has learned and demonstrated, the client's reported focus on the children's adjustment, standardized measure trends (for example, PHQ-9 or GAD-7 scores over time).

Current clinical status. A factual statement of stability and functioning as observed at the time of writing.

Authorization and availability. Note that a written release is on file, and state your availability to answer questions within the scope of your treating role — language that gently pre-limits any later testimony.

What to exclude. Session content; the client's account of the other parent or the marriage; statements about the children if they are not your client; predictions of future behavior; risk opinions; diagnostic detail beyond what is authorized and relevant; and, above all, anything resembling a recommendation about custody or parenting time.

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How to Write It Step by Step

Step 1: Decide whether to write at all. You are never obligated to write a custody letter, and sometimes the right answer is a respectful no. Consider whether the letter could damage the treatment, whether you would be drawn into testimony you do not want to give, and whether the client actually needs a forensic evaluation instead. If you decline, explain why, offer alternatives (a factual records release, or information about requesting a neutral evaluation), and document the conversation.

Step 2: Clarify who your client is. If you treat one parent, the analysis on this page applies directly. If you treat the child, the risks multiply: a letter for one parent can compromise the child's treatment and typically requires authorization consistent with the legal custody order — read the order, know your state's rules on minors' records, and consider a standing policy of non-involvement in the parents' litigation. If you provide couples or family therapy to both parents, writing for either one is a conflict; decline and document.

Step 3: Obtain written, specific authorization. The release should name the recipient (court, attorney, GAL), the purpose, and the categories of information disclosed. Show the client the actual draft before they sign off. For minor clients, obtain authorization from the holder or holders of legal custody as your jurisdiction and the custody order require.

Step 4: Draft the scope statement before anything else. Writing the limitations paragraph first disciplines the rest of the letter. Every sentence you add afterward should survive the test: "Is this within the scope I just declared?"

Step 5: Report facts and observations, not conclusions. Attendance numbers, dates, described behaviors, skills demonstrated in session, measure scores over time. Replace "she is a devoted mother" (a conclusion about parenting you cannot support) with "in session, she regularly initiates discussion of her children's adjustment and has practiced specific strategies for shielding them from adult conflict" (an observation you can).

Step 6: Say nothing about people you have not evaluated. No characterizations of the other parent, even ones that merely repeat your client's account. No statements about the children's preferences, attachment, or wellbeing unless the child is your client and disclosure is properly authorized — and even then, no custody-relevant opinions.

Step 7: Review the letter with your client. They should understand that the letter enters the court record, that opposing counsel will read it, and that it may lead to a subpoena for your testimony or records. This is informed consent, not a formality.

Step 8: File and document. Keep the letter, the signed release, and a note documenting the request, your role-boundary discussion, and the client's consent to the specific content.

Common Mistakes

Making a custody recommendation. The cardinal error. "The children should reside primarily with my client" is an opinion you lack the data, the neutrality, and — under the APA custody guidelines — the role to give. It will be challenged, and the challenge will succeed, taking your credibility and your client's position down with it.

Vouching for parenting capacity. "He is an excellent father" is a parenting-capacity opinion in casual clothing. You have observed your client in a therapy office, not with his children. Describe what you have actually observed.

Commenting on the other parent. Everything you know about the other parent came from your client. Courts know this. A letter that criticizes a parent the writer has never met reads as advocacy and discredits the factual content around it.

Writing about a child client for one parent in a contested case. Even a well-intentioned letter can breach the other parent's rights regarding the minor's treatment information and convert the child's therapy into litigation material. When in doubt, route requests through the GAL or the court.

Omitting the scope statement. Without it, opposing counsel will try to walk you into forensic territory at deposition. With it, your boundaries are on the record before anyone asks a question.

Treating an attorney's subpoena as a court order. In many jurisdictions it is not. Contact your client, then your own attorney or malpractice carrier's legal line, before releasing records or agreeing to testify.

Ethical Considerations

Multiple relationships and role integrity. APA Ethics Code Standard 3.05 cautions against multiple relationships that impair objectivity or risk exploitation. Serving simultaneously as a client's therapist and as an opinion witness in their custody case is a textbook example. The AFCC Model Standards and APA custody guidelines resolve it the same way: the roles do not mix. Holding this boundary is not a failure to help your client — it is what keeps your factual documentation credible enough to help them.

Informed consent and foreseeable consequences. A custody letter changes the treatment. Clients should understand before you write it that therapy discussions may now feel litigation-adjacent, that the letter is discoverable, and that you could be compelled to testify about the treatment more broadly. Some clients, once they understand this, decide a letter is not worth the exposure.

Minimum necessary disclosure. A custody file is read by the judge, both attorneys, a GAL, and sometimes the other parent personally. Disclose the least clinical information that accomplishes the documented purpose. Functional descriptions usually serve better than diagnoses; diagnoses serve better than history; session content should virtually never appear.

Honesty under pressure. Standard 5.01 requires that professional statements be accurate and not misleading. Pressure from a frightened client or a zealous attorney does not change what your data support. If you cannot say it accurately, do not say it.

Competence at the clinical-legal interface. If family-law contexts are unfamiliar, consult a forensically experienced colleague before responding to a custody-related request. For the full forensic framework — what a neutral evaluator actually does, and why your letter must not imitate it — see the custody evaluation report guide and our general guide to letters to the court from a treating therapist.