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Mental Capacity Assessment for Paramedics: MCA Test Guide

By Steve Updated 14 Oct 2026 21 min read

 

 

Mental capacityTest not startedIn progressHas capacityLacks capacityUnresolvedGo to capacity test

 

Mental health toolkit for paramedics › Law and consent · England and Wales

Mental capacity: how to assess it, and what to do next

Capacity is not “alert and orientated to person, place and time”. It is whether this patient can make this decision, now. This page walks through the legal test one question at a time and ends with a clear answer.

Go straight to the capacity test

On this page

  1. What capacity is
  2. The capacity test (interactive)
  3. What happens next
  4. Refusal of care when the patient has capacity
  5. Under 18s: children and young people
  6. Who can do what: clinicians, police, GP
  7. What to record
  8. Terms, sections and codes (including section 5)
  9. Sources

What capacity is

The Mental Capacity Act 2005 (MCA) applies to people aged 16 and over in England and Wales. Under-16s follow different rules: see Under 18s. Capacity is decision-specific and time-specific: someone can decide to take paracetamol but not to refuse a hospital admission, and can lose it and regain it within the same shift. A diagnosis, an age or an odd-looking choice never settles it on its own.

The five principles

  1. Presume capacity. Assess only when you have a reason to doubt it. The burden is on you, not the patient, to show it is lacking, on the balance of probabilities.
  2. Support decision-making. Take every practicable step first.
  3. Unwise is not incapable. Patients may make decisions you disagree with.
  4. Best interests. If capacity is lacking, act in their best interests.
  5. Least restriction. Choose the option that restricts rights and freedom least.

The two-stage test

Stage Question
1. Impairment Is there an impairment of, or disturbance in the functioning of, the mind or brain? Temporary or permanent.
2. Function Because of it, can the patient understand, retain, use or weigh the relevant information, and communicate their decision? Failing any one means lacking capacity.

The link between the two matters (the “causative nexus”). The inability must be because of the impairment or disturbance. But the definition is wide, includes temporary states, and needs no formal diagnosis, so a patient who clearly fails the four abilities almost always has one: look harder for it. If a patient clearly fails the abilities and nothing else explains it (language, missing aids, fear, pressure from someone), a clinician can reasonably infer a disturbance and record that reasoning, even without a named diagnosis. If something else does explain it, fix that and reassess.

Orientation and cognitive screens are not enough. Knowing the date or the Prime Minister’s name shows some things, but a patient can pass them and still be unable to weigh a decision, or fail them and still decide well. A screening test is not a capacity assessment: the Act’s test is decision-specific and asks about the four abilities. Use orientation and cognitive screens as supporting information only.

The capacity test

This test is for patients aged 16 and over. For under-16s see Under 18s. Name the specific decision first, for example “refusing conveyance to hospital after a collapse”. Then work down. Each step tells you what to ask, what you need to hear, and what must not count against the patient.

Step 0. Before you judge anything

Tick what you have done. Treat reversible causes first, then ask again.


Rule these out first. Fix what you can, then ask again. Some of these are impairments themselves (low glucose, low oxygen), so treat them and reassess when safe.

Senses and speech






How you asked



Physical and medical causes




Surroundings and people





Step 1. Is there an impairment or disturbance of mind or brain?

What you need: some evidence, not a guess. The definition is wide and includes temporary states, and no formal diagnosis is required. You cannot diagnose everything at the scene. If they clearly fail the steps below and nothing else explains it, choose “Likely” and record why. Examples: dementia, delirium, stroke, head injury, hypoglycaemia, hypoxia, sepsis, intoxication, severe mental illness, learning disability, severe pain or shock.



Step 2. Can they understand the information?

“Can you tell me in your own words what has happened to you, and what we are suggesting?”

What you need: a grasp of the nature of the problem, the proposed options, and the likely benefits and risks of each, including doing nothing. Give the information in plain language first, in whatever form helps (pictures, written, slower).

Not a failure: using different words from yours, or not recalling medical terms.


Step 3. Can they retain it long enough to decide?

“We have just talked about a few things. What are the main points you remember?”

What you need: they hold the key points for the length of the conversation and the decision. Check again after a short pause.

Not a failure: forgetting details later, or needing notes or reminders. Poor long-term memory alone does not remove capacity.


Step 4. Can they use or weigh the information?

“What are the good and bad points of going to hospital? And of staying here? What do you think happens if you don’t go?”

What you need: they connect the information to their own situation and balance it, so that it actually shapes the decision. Watch for denial that anything is wrong, a fixed false belief, or no reasoning at all (“I just don’t”) that relates to the risks you explained.

Not a failure: reaching a choice you disagree with, valuing different things, or accepting a risk you find too high. That is the right to an unwise decision.


Step 5. Can they communicate their decision?

“So what would you like to do?”

What you need: a decision shown by any means: speech, writing, gesture, blinking, a board. Try every practicable method before deciding they cannot.

Not a failure: a decision that changes once, if it is made for reasons they can explain. Repeated flip-flopping with no reasoning may point to a problem at step 4.


Answer: not yet complete

Answer every step above to get a result.

Still to answer: ImpairmentUnderstandRetainUse or weighCommunicate

Answer: HAS capacity for this decision

Able to understand, retain, use or weigh, and communicate. Impairment, if any, does not remove capacity when all four are met. Next: respect the decision and safety-net.

Answer: LACKS capacity for this decision

Unable to: UnderstandRetainUse or weighCommunicate

This is because of an impairment or disturbance of the mind or brain. Failing any one element is enough. Next: best interests decision. Check for an ADRT and LPA first.

Answer: LACKS capacity for this decision

Unable to: UnderstandRetainUse or weighCommunicate

No cause could be named at the scene, but nothing else explains it, so a disturbance of the mind or brain is reasonably inferred (record this reasoning). Failing any one element is enough. Next: best interests decision. Check for an ADRT and LPA first.

Answer: unresolved. Deal with the other explanation first

Unable to: UnderstandRetainUse or weighCommunicate

You said something other than an impairment explains this, such as language, missing communication aids, fear, or someone pressuring them. That is not a finding of lack of capacity, and the presumption of capacity stands. Fix the cause (interpreter, aids, privacy, time away from the person influencing them), then reassess. If you cannot fix it and the risk is serious, get senior advice and consider safeguarding.

This is a learning aid, not a legal determination. The real assessment, and your record of it, is yours.

What happens next

If the patient has capacity

  • Respect the decision, including a refusal, even if it risks harm or death. Follow the refusal of care pathway. Treating a capacitous adult against their wishes is generally unlawful, apart from specific legal powers such as the Mental Health Act.
  • Re-explain the risks and consequences in plain terms and offer alternatives (a different treatment, a GP or urgent care appointment, a later change of mind).
  • Ask whether they will accept any part of the care, and give clear safety-netting: what to watch for and who to call, including 999.
  • Invite them to speak to a clinician by phone if that helps, and involve family only if the patient agrees.
  • Think about safeguarding. A capacitous adult can still be at risk from abuse, neglect, self-neglect or coercion. You can raise a concern even if they do not want you to, and should seek their consent where you can.
  • Record the whole conversation and sign-off where your service requires it.

If the patient lacks capacity

  1. Is the decision urgent? If not, can it wait for capacity to return? If they may regain it, reassess.
  2. Check for a valid and applicable advance decision to refuse treatment (ADRT). It has the same force as a capacitous refusal for that treatment. For life-sustaining treatment it must be written, signed and witnessed, and state that it applies even if life is at risk.
  3. Check for a registered Lasting Power of Attorney (health and welfare) or a court deputy. An attorney can decide only within their powers; life-sustaining treatment must be expressly covered. Family or “next of kin” cannot consent unless they hold this authority, though you must consult them.
  4. Make a best interests decision. Do not assume from age, appearance or condition. Consider their past and present wishes, beliefs and values, and the views of family, carers and others involved. Weigh the benefits and burdens of every option, and avoid risk-averse defaults.
  5. Choose the least restrictive option that still meets the need. Restraint is lawful only if proportionate to the risk of serious harm and in their best interests. Restrictions to protect other people need another legal route, such as the Mental Health Act or police powers.
  6. Seek help for serious or contested decisions: senior clinician, clinical desk, an Independent Mental Capacity Advocate (IMCA) where there is no one appropriate to consult, and the Court of Protection for complex cases.
  7. Involve the patient as far as possible. Lacking capacity for one decision does not remove their voice.
  8. Consider whether care amounts to a deprivation of liberty, and raise it using your organisation’s process.

Emergencies. If a patient lacks capacity and needs immediate treatment to save life or prevent serious deterioration, section 5 protects you when you act in their best interests with reasonable belief, unless a valid ADRT applies.

Other nations. The MCA covers England and Wales. Scotland uses the Adults with Incapacity (Scotland) Act 2000, and Northern Ireland uses the Mental Capacity Act (Northern Ireland) 2016. Check your local law and policy.

Refusal of care when the patient has capacity

A refusal is valid only if the patient has capacity for that decision and has the information to decide. This is good practice built on the MCA principles, NICE NG108 and the Bexley toolkit. Your trust’s refusal policy and JRCALC take precedence, and I could not access JRCALC.

  1. Do the capacity test first. Work through the test, including the Step 0 checks. A refusal from someone who is hypoxic, hypoglycaemic, intoxicated or in severe pain may not be valid.
  2. Say what you are worried about, plainly. Name the possible diagnosis or risk, including serious harm or death if that is realistic. Ask them to tell you back what they understand.
  3. Explain what you are offering and what happens if they do not accept: the likely course, how fast things could change, and what could be missed.
  4. Offer alternatives, not just a yes or no: treatment on scene, a different destination, a GP or urgent appointment, a phone call with a senior clinician, or someone staying with them.
  5. Check it is their own decision. Is someone pressuring them, or answering for them? Speak to them alone if you can.
  6. Get senior or clinical desk advice for high-risk refusals, as your policy requires. Offer the patient the chance to speak to that clinician.
  7. Safety-net. Give specific warning signs, who to call and when, and a plain statement that they can change their mind and call back. Ask someone to stay with them and leave written advice if you can.
  8. Check it is safe to leave: warmth, access to a phone, medicines and food, and whether anyone depends on them.
  9. Think about safeguarding. Concerns about abuse, neglect, self-neglect or coercion are still yours to raise, ideally with the patient’s agreement.
  10. Record it and follow your policy on refusal forms, signatures and handover. If they will not sign, record that.

Refusal after self-harm, an overdose or suicidal thoughts. A patient may still have capacity, but low mood, psychosis or acute distress can impair the ability to weigh the risks. Assess more carefully, treat any physical cause, and get senior advice. If they lack capacity, act in their best interests. If a mental disorder is the concern, ask about Mental Health Act options (see Who can do what).

If their capacity changes (the effect of a drug wears off, or they become drowsy or confused), reassess. Capacity can be lost as well as regained.

Under 18s: children and young people

The MCA does not apply to under-16s, and the interactive test above is not designed for them. Rules differ by age, and by nation. Get senior advice early with any refusal or disagreement.

Age Who can consent If they refuse
Under 16 The child can consent if Gillick competent: they must show they understand what is involved, decision by decision. Otherwise someone with parental responsibility can consent, and one person is enough. A competent child’s refusal can in some cases be overruled, but that is for the courts to decide, not something to settle on scene. Seek senior advice.
16 to 17 Presumed to have capacity under the MCA, and entitled to consent to their own treatment. If they lack capacity, the MCA applies and best interests decide, and in England, Wales and Northern Ireland someone with parental responsibility can usually also consent. A refusal by a 16 or 17 year old with capacity should normally be respected, and can be overruled only in exceptional circumstances, such as probable death or severe permanent injury, through the courts. Seek senior advice at once.
18 and over Adult rules apply: the MCA test, advance decisions and LPAs. As for any adult with capacity.

What to do on scene

  • Emergencies. If treatment is vital and waiting for consent would put the child at risk, treatment can go ahead without it, in the child’s best interests.
  • Find out who has parental responsibility. Not everyone with the child does. Do not delay emergency care to establish it.
  • If parents refuse for a child, the courts can overrule a refusal that is not in the child’s best interests. Do not argue it on scene: get senior and clinical desk advice, keep the child safe and record everything.
  • Involve the young person. Explain in language they can follow and take their views seriously, whatever their age.
  • Safeguarding is always part of the picture: injury patterns, who is present, and who they will be with if left.
  • Advance decisions and LPAs are for people aged 18 and over only.

Scotland. People aged 16 and 17 are treated as adults. A competent child under 16 can consent in their own right, and a 16 or 17 year old who lacks capacity is treated like an adult who lacks capacity, so parents cannot consent for them. Check your local law and policy.

The age thresholds above follow NHS and medical-defence-body guidance. The detail of how Gillick competence is assessed on scene, and the point at which a young person’s refusal may be overridden, are matters for senior advice and your trust’s policy, not for the page.

Who can do what

The Mental Capacity Act gives protection to anyone acting in a lacking patient’s best interests. It gives no special powers to any profession. Detention and entry powers come from the Mental Health Act (MHA) and the police.

Who What the law allows What it does not
Ambulance clinician alone Section 5 protects care and treatment, including conveyance, if you took reasonable steps to assess capacity, reasonably believe they lack it, and reasonably believe it is in their best interests. Section 6 allows restraint only if it is necessary to prevent harm to them and proportionate to the likelihood and seriousness of that harm. No MHA powers. No power under the MCA to detain beyond what the care needs, to restrain to protect other people, or to force entry.*
Police: section 136 MHA If a person appears to a constable to have a mental disorder and be in immediate need of care or control, the officer can remove them to a place of safety when necessary in their interests or to protect others. It can be used anywhere except a dwelling (a home and its private garden, garage or outhouse). The officer can enter by force to use it and must consult, if practicable, a doctor, nurse, AMHP or a person specified in regulations. The officer keeps responsibility for the decision. They normally request an ambulance, and the paramedic makes the clinical decisions during the journey. Not usable inside a dwelling, though it applies in shared areas such as a communal hallway or garden, and elsewhere. Not a clinical decision for the paramedic to make. Detention for assessment is limited to 24 hours from arrival at the place of safety, which a doctor can extend by up to 12 hours. The older 72-hour limit no longer applies.
Police: section 135 MHA An AMHP applies to a magistrate for a warrant. Police can then enter premises, if need be by force, and may be accompanied by a doctor or AMHP, to remove the person for assessment. The AMHP normally arranges transport, often an ambulance, and police transport only if violence makes that unsafe. Not available without a warrant.
Police: other powers* Entry to save life or limb, and breach of the peace powers. Police can also help you carry out lawful section 5 and 6 care. They are not a substitute for section 136 where that applies. Police guidance says to use section 136 and not rely on the MCA, because capacity can fluctuate.
GP* Gives clinical information and history, can arrange urgent care, and can take part in a Mental Health Act assessment. That needs an AMHP and doctors, including one with specialist approval. A GP cannot detain or treat against a capacitous patient’s wishes, and has no MCA powers beyond section 5.

* Marked points come from my own understanding of the law, not from a source I could read. Check them against the Act, the Code of Practice and your trust policy.

Mental Health Act 2025. It became law in December 2025 and amends the 1983 Act, but most of it will be phased in over eight to ten years. When in force it will end police cells as places of safety for adults in crisis. Until you are told your area has changed, work to the current sections 135 and 136.

Ask for help when: the patient is in a private home and needs detaining, they are a risk to others, restraint is likely, or the decision is contested. Call the clinical desk, the police or the AMHP service early, and record who you spoke to.

What to record

  • The specific decision, date and time, who assessed, and who else was present.
  • Why you doubted capacity, and the practicable steps taken to support the decision.
  • The information given, the patient’s own words or responses at each of the four steps, and the impairment you found.
  • Your conclusion and reasoning. If lacking, which element failed, and why that is because of the impairment.
  • For a best interests decision: who you consulted, the options weighed, and why the chosen one is least restrictive.
  • Any refusal, advice given, safety-netting and handover or referrals.

Terms, sections and codes

Tap a link in the text above and it lands you here.

Section 5: protection when acting for someone who lacks capacity

Normally you cannot touch a person or their property without consent. Section 5 gives you legal protection from liability for acts connected with a person’s care or treatment, even without their consent, if all of these are true:

  • You took reasonable steps to establish whether they have capacity for this decision.
  • You reasonably believe they lack capacity for it.
  • You reasonably believe the act is in their best interests.

It covers personal care (washing, dressing, toileting, help eating and moving) and treatment (giving medication, diagnostic tests, nursing care, taking someone to hospital, emergency care and procedures). Anyone can rely on it, including paid staff, family carers and clinicians.

Limits. It does not protect negligence, and it does not override a valid and applicable advance decision to refuse that treatment. It does not cover restraint that is disproportionate to the risk of harm or not in the person’s best interests (see section 6). It does not replace the decision of an attorney or deputy acting within their powers. It does not authorise a deprivation of liberty, apart from limited cases of life-sustaining treatment or a vital act while a court decision is sought.

Section 6: restraint

Restraint means using or threatening force to do something the person resists, or restricting their liberty whether they resist or not. It is allowed under the Act only if you reasonably believe it is necessary to prevent harm to the person and it is a proportionate response to the likelihood and seriousness of that harm. Restraint to protect other people needs a different legal route.

Section 4: best interests checklist

The steps for deciding for someone who lacks capacity: do not make assumptions from age, appearance or condition; consider whether they may regain capacity and whether the decision can wait; involve the person as far as possible; find their past and present wishes, feelings, beliefs and values; consult family, carers, attorneys and others; weigh the benefits and burdens of each option; and choose the least restrictive one. Record the reasoning.

Sections 1 to 3: principles and the test

Section 1 sets the five principles. Section 2 defines lack of capacity (unable to decide because of an impairment or disturbance of the mind or brain). Section 3 sets the four abilities: understand, retain, use or weigh, and communicate.

ADRT: advance decision to refuse treatment

A decision made earlier, by a person aged 18 or over with capacity, to refuse a specified treatment in specified circumstances. If valid and applicable it is binding. For life-sustaining treatment it must be in writing, signed, witnessed and say it applies even if life is at risk.

LPA: Lasting Power of Attorney

A person chooses someone to decide for them. There are two types: property and financial affairs, and health and welfare. It must be registered with the Office of the Public Guardian (OPG) before use. Authority over life-sustaining treatment must be stated in the document.

Deputy and Court of Protection

The Court of Protection makes decisions for complex or disputed cases and can appoint a deputy to make ongoing decisions. The OPG registers LPAs and supervises deputies.

IMCA: Independent Mental Capacity Advocate

An advocate for a person who lacks capacity and has no one appropriate to consult, in decisions such as serious medical treatment or a change of accommodation. An IMCA is not needed where the treatment is urgent.

Gillick competence

The test for whether a child under 16 can consent to their own treatment: do they understand enough to fully appreciate what is involved? It is specific to the decision, and competence has to be shown, not assumed. It is separate from the MCA.

Parental responsibility (PR)

The legal rights and duties a parent or other person holds for a child. For a child who cannot consent, one person with PR giving consent is enough for treatment. Check who holds it. Not everyone present does.

DoLS: Deprivation of Liberty Safeguards

The legal process authorising deprivation of liberty in care homes and hospitals for people who lack capacity, based on Article 5 of the Human Rights Act. It sits within the MCA and uses the same principles. Check whether your area still uses DoLS or has moved to its planned replacement, the Liberty Protection Safeguards.

Causative nexus

The link the test requires: the inability to understand, retain, weigh or communicate must be because of the impairment or disturbance of the mind or brain.

Code of Practice

The statutory guidance on how to apply the Act. Those working under the Act must have regard to it.

Explanations are summaries drawn from the Bexley toolkit and the Act. Read the Act and Code of Practice for the exact wording.

Sources

  • Bexley Safeguarding Adults Board, Mental Capacity Act 2005 Competency Toolkit: five principles, functional and diagnostic tests, causative nexus, best interests checklist, ADRT, LPA and acts in connection with care.
  • NICE, Decision-making and mental capacity (NG108): supporting decision-making, assessing capacity for a particular decision, and recording the practicable steps taken and the outcome.
  • Mental Capacity Act 2005 and the MCA Code of Practice.
  • NHS, Consent to treatment: children and young people, and MDDUS and Royal College of Anaesthetists guidance on consent in children: age thresholds, Gillick competence, parental responsibility, refusal in 16 and 17 year olds, and the Scottish difference.
  • JRCALC Clinical Guidelines (subscription app): I could not access the JRCALC text, so this page is aligned to the MCA and NICE and does not quote JRCALC. Check your current JRCALC capacity and consent guidance before relying on it.
Educational resource for clinicians and students. It does not replace the Act, the Code of Practice, your trust policy or senior clinical advice.

Quick Overview

  • 21 minute read
  • Intermediate level
  • Updated 14 Oct 2026

Key Learning Points

  • What capacity is
  • The five principles
  • The two-stage test
  • The capacity test
  • Step 0. Before you judge anything
YOUR LEARNING

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