Forensic sections: Part 3 of the Mental Health Act

What is Part 3 of the Mental Health Act?

Part 3 covers patients concerned in criminal proceedings or under sentence. It lets a court send someone to hospital instead of prison, before trial or at sentence, and lets the Justice Secretary move a prisoner to hospital for treatment.

People in custody or before the courts have the same right to assessment and treatment as anyone else (Code 22.3). A prison healthcare centre isn't a hospital under the Act, so nobody can be treated there without consent under the MHA (Code 22.30).

Don't confuse Part 3 with section 3. Section 3 is civil admission for treatment under Part 2, made on an application, usually by an AMHP. Part 3 orders come from a court or the Justice Secretary.

Restricted or unrestricted: who decides what

The group someone is in tells you who controls leave, transfer and discharge.

In the restricted column, a tribunal can discharge a s37/41 patient on its own. For s45A and s47/49 patients it needs the Justice Secretary's agreement, and a s48/49 patient goes back to custody instead (s74). Restricted patients and the Ministry of Justice explains how MHCS works.

The medical evidence courts need

• At least one s12 doctor. Every Part 3 remand, order and transfer needs at least one doctor approved under s12. For s35 there's only one doctor, so that doctor must be (s54(1)).
• Written reports usually do. A court can act on a signed report, but it can call the doctor (s54(2), (2A)). So can the defendant, who can also call evidence to rebut it (s54(3)).
• Oral evidence for restrictions. A restriction order and a hybrid order both need at least one doctor to have given evidence in person (s41(2), s45A(4)).
• Advice, not a general report. The court wants to know whether to divert the person from prison (Code 22.9). Say who asked for the report, and explain the limits of confidentiality before you start (Code 22.10).
• Fitness to plead, not guilt. Assess fitness to plead, and don't speculate about guilt or innocence (Code 22.20). Psychiatric reports for court covers the structure.

Finding a bed: the admission deadlines

Each court order and transfer needs a bed agreed in advance, and each has its own deadline.

A hospital order or transfer direction lapses if the deadline passes (Ref Guide 15.8; s47(2)). For an adult, a place of safety can be a police station, a prison or a hospital willing to take them (s55(1)).

If no bed can be found for a hospital, interim or hybrid order, the court can ask the integrated care board or NHS England what's available. They must answer (s39). Prison shouldn't be the default (Code 22.31). After an insanity or unfitness finding, no bed offer is needed (Code 22.11).

Practical points for Part 3 patients

• Don't treat Part 3 like Part 2. A remanded or interim order patient can't have s17 leave, and only the court can end the order (Ref Guide 14.20, 18.14).
• Check for a named unit. If the order names a unit or ward, a restricted patient can't go beyond it without the Justice Secretary's consent, even within the hospital grounds (MHCS leave guidance 5.5).
• Use Part 2 when you need it. If charges are dropped, an AMHP may need to consider a civil application (Code 22.5). A civil section can also run alongside a s35 remand (Code 22.41).
• Bring in liaison and diversion early. These services identify, assess and refer people in police custody and the courts. They don't provide treatment themselves (Code 22.6).

What the 2025 Act has already changed for forensic patients

Most of the Mental Health Act 2025 isn't in force yet. The changes that matter in forensic work started on 18 February 2026 (MHA 2025 s56(1)).

• Supervised discharge. A restricted patient can now be conditionally discharged on conditions that amount to a deprivation of liberty. The Justice Secretary must be satisfied they're necessary to protect the public from serious harm (s42(2A)).
• The tribunal's test. A tribunal must be satisfied the conditions are necessary to protect another person from serious harm. Discharge on them must also be no worse for the patient's mental health than staying in hospital (s73(2)(c)).
• It reverses MM. In MM (2018) the Supreme Court held that the Act didn't allow such conditions for a patient with capacity. The new power also covers patients already detained or discharged when it started (EN 275, 279).
• Tribunal rights to match. A patient on these conditions can apply between 6 and 12 months after they start, then every 2 years. The Justice Secretary must refer at 12 months, then every 2 years, if no tribunal has considered the case (s75(2A), (2C), (2D)).
• Wider s48 transfers. Section 48 now reaches more kinds of immigration detention, and children remanded to youth detention accommodation by any court (s48(2)(a), (d)).

Supervised discharge in practice

MoJ guidance calls supervised discharge the last option rather than the first, and not a stepping stone to an ordinary conditional discharge. It suits a small number of patients, often with static, lifelong conditions, who no longer benefit from hospital but need close supervision (MoJ guidance 1.5, 2.1).

It isn't for anyone who can use regular unescorted community leave (2.3). Expect a long run-up: an early talk with an MHCS senior manager, then testing on escorted day and overnight leave to the proposed address (3.4 to 3.6).

One catch: the guidance still defines deprivation of liberty by the Cheshire West acid test, which AGNI overruled on 2 June 2026. Read it alongside deprivation of liberty after AGNI.

The 28-day limit on prison transfers

For now, 28 days is a target in NHS England's 2021 guidance. New ss47A and 48A will make it a legal duty, and DHSC aims to bring them in by December 2027.

• When the clock starts. With the first request for a doctor's report on whether the transfer criteria are met. The body making it must notify the Justice Secretary, the prison and the NHS bodies likely to be involved (s47A(1) to (3)).
• What they must seek to ensure in 28 days. The decision on transfer, the warrant if there is one, and the move to hospital, unless there are exceptional circumstances (s47A(4)).
• What isn't exceptional. A shortage of beds or staff, unless something else exceptional caused it (s47A(5)).
• A change to the treatment test. Case law (ASK, 2019) treats treatment as available only once a bed has been identified. The Act will let the criteria be met before a bed is found, but that change isn't in force yet (EN 281 to 283).

Changes still to come

• Criteria. The therapeutic benefit test for appropriate treatment will apply to Part 3 as to Part 2 (EN 90, 92). The serious harm test reaches Part 3 only through renewal, CTOs and tribunal discharge, not the court's decision (EN 75, 81, 87, 89).
• Autism and learning disability. Part 3 keeps today's approach, because for this group the alternative to hospital is prison. Learning disability still needs abnormally aggressive or seriously irresponsible conduct (EN 36, 38).
• A nominated person. Restricted, remand and interim order patients have no nearest relative now. They'll be able to have a nominated person with limited rights, such as information and a say on the care plan (EN 197 to 200).
• Places of safety. Prisons and police stations will stop being places of safety for Part 3, except for people already held there when the change starts (MHA 2025 s48; EN 353, 354).
• Remand for own protection. Courts won't be able to remand an adult in custody solely for their own protection on mental health grounds. Bail conditions, s35 or s36 are the alternatives (MHA 2025 s49; EN 357).

DHSC puts the new criteria and the nominated person in Phase 1, indicatively 2028/29. The places of safety change comes later, and the bail change has no date yet. Until then the 1983 Act as amended and the 2015 Code are the law. See the Mental Health Act 2025.