Understanding NHS trust types
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This article is part of a series: OpenPrescribing Hospitals: Organising Organisations
OpenPrescribing Hospitals supports the analysis of medicines issued across NHS trusts in England. These trusts vary in size, degree of specialisation and the severity of illnesses that they care for. Some trusts have emergency departments and offer acute care, while others focus on longer-stay rehabilitation, mental health or community-based follow-up care. Some provide a broad range of services, whereas others are specialised in a single clinical area. These factors determine the quantity and range of medicines a trust uses, so understanding the type of trust provides useful context when analysing medicines usage in secondary care. Here, we explain what types of trusts exist in more detail, how they can be identified and how we plan to use trust categories on OpenPrescribing Hospitals.
What types of NHS trust are there?
NHS trusts can be broadly categorised into four types:
- Hospital/acute trusts provide hospital-based secondary care such as Accident & Emergency, surgery and inpatient care.
- Mental health trusts provide specialist mental health care and treatment. This is delivered in hospitals and through community mental health services.
- Community health trusts provide community-based care such as health visits and rehabilitation services.
- Ambulance services trusts provide emergency and non-emergency ambulance services.
Determining trust types
The type of a trust is often obvious from the trust’s name. Examples include Avon and Wiltshire Mental Health Partnership NHS Trust and South Central Ambulance Service NHS Foundation Trust. Others, such as Cambridgeshire and Peterborough NHS Foundation Trust (a mental health trust) are less obvious.
Unlike other trust characteristics such as name and relationship to other organisations, (which we’ve written more about in our post, Organising Organisations: Hospital Trusts in OpenPrescribing Hospitals) the type of a trust is not contained within the structured information provided by the Organisation Data Service. But we’ve found another source where it is: the Estates Returns Information Collection (ERIC).
What is the Estates Returns Information Collection (ERIC)?
The ERIC is a mandatory data collection for all NHS trusts. It contains information relating to the costs of providing and maintaining NHS Estates and includes an indication of trust type. This is published annually (between October and December).
The trust types reported in ERIC determine which Aggregated Metric Rankings league table a trust appears in (they can only appear in one). The different league tables are shown in the table below.
Trust types within the Estates Returns Information Collection
The four broad types of trust described above provide some indication about the services a trust offers and the patients they care for, but they don’t allow separation of trusts according to size and degree of specialisation. The trust types within the ERIC are more granular and include the following categories:
- Acute - Small
- Acute - Medium
- Acute - Large
- Acute - Teaching
- Acute - Specialist
- Acute - Multi-Service
- Mental Health and Learning Disability
- Community
- Ambulance
Acute trusts are sub-categorised by: size, whether they offer specialist services, and if they are teaching trusts (associated with a medical school). There is also an extra category for Care Trusts (introduced in 2002 to provide better-integrated health and social care but have now largely disappeared as a result of NHS reorganisations). Some trusts may offer care spanning across more than one of these categories, but each trust can only be assigned to a single category.
There are no descriptions of trust types in the data definitions file provided alongside the collection, but it does include a description for site types (we’ve explained the difference between trusts and sites previously). Trusts have to report the number of sites of each type that they manage and these align loosely with the trust types. The most relevant subset of site type definitions for understanding trust types, taken from the metadata, are shown in the table below.
| Site type | Description |
| General acute | Sites that provide a range of inpatient medical care and other related services for surgery, acute medical conditions or injuries (usually for a short term illness or condition) |
| Specialist hospital (acute only) | Sites that undertake a single specialist function, inclusive of oncology, orthopaedics, dental hospital, maternity hospital, children’s hospital, cardiothoracic. |
| Mixed service hospital | Sites where two or more functions are provided by the same provider. Such functions would include any combination of single speciality, acute services, community services, mental health services and learning disabilities services. |
| Mental Health (including Specialist services) | Sites exclusively providing mental health services including specialist mental health services e.g. secure units. |
| Learning Disabilities | Sites exclusively providing learning disabilities services. |
| Mental Health and Learning Disabilities | Both mental health and learning disabilities provided from the same site by the same provider. |
| Community hospital (with inpatient beds) | Sites that provide an alternative to acute, general hospital care, closer to people’s homes and responding to local need. There may be a minor injuries unit but not an emergency department. May also include inpatient care for older people, rehabilitation or maternity services, out-patient clinics and day surgery/care as well as diagnostics. |
| Support facilities | Sites that are administrative or other support service sites, ambulance stations including control centres, standby points and radio masts, education and training, and any other non-hospital site where patients are not treated or accommodated. Sites solely used for the provision of staff residential accommodation should be included. |
Distribution of trusts by type
The table below shows the total number of each trust type reported in the ERIC in 2024/25.
| Trust type | Number of trusts | |
| Total | 207 | |
| Acute | Total | 135 |
| Small | 19 | |
| Medium | 20 | |
| Large | 23 | |
| Specialist | 16 | |
| Multi-service | 7 | |
| Community | 15 | |
| Care | 2 | |
| Mental Health and Learning Disability | 45 | |
| Ambulance | 10 | |
The type of individual NHS trusts, and the number of sites of different types they contain can be found in ERIC site metadata file. This shows some commonalities in the distribution of site types for the different trust types, but this isn’t the only determining factor.
Using trust type on OpenPrescribing Hospitals
The trust type categorisations available through the ERIC provide a way to group trusts in a structured format that is updated regularly. This will be useful for trust-level analysis on the platform, but before we incorporate the trust types, we’re going to have a deeper look at the issuing patterns for the trusts within each category. This will give us a better understanding of variation across and within trusts of different types. For now, we’ve made the trust type available as a filter when selecting a trust type on the Submission History page.