# Get treatment category by ID

Returns the single treatment category matching `id` for the practice identified by
`X-Practice-Id`. The identifier is the same `id` returned when listing treatment
categories.
**Practice-wide:** treatment categories belong to the practice as a whole, not to a
site. Lookup is by practice and `id` only; no `site_id` is needed or accepted.
If no treatment category exists for that practice and `id`, the API responds with
404.

Endpoint: GET /treatment_categories/{id}
Version: 2026-01-01
Security: oauth2

## Security:

  - `oauth2` (unknown)
    oauth2 scopes: treatment:read

## Path parameters:

  - `id` (string, required)
    Resource identifier to filter/find.

## Header parameters:

  - `X-Practice-Id` (string, required)
    UUID of the **practice** in whose context the request is executed. The API
uses this to resolve data the caller is permitted to access for that practice.

## Response 200:

  - `200` (unknown)
    Full details for one treatment category.

## Response 200 fields (application/json):

  - `data` (object, required)
    A **treatment category** is a practice-defined folder that groups treatments in the Dentally treatment catalogue, for example Diagnostic Related Services or Restorative. Every treatment belongs to exactly one treatment category.
Treatment categories are **practice-wide**. They are not tied to a site, so the list returned for a practice is the complete catalogue, and no `site_id` is returned or accepted as a filter.

  - `data.created_at` (string, required)
    When the resource was created (UTC, ISO 8601) in UTC.
    Example: 2024-01-15T09:30:00Z

  - `data.updated_at` (string, required)
    When the resource was last updated (UTC, ISO 8601) in UTC.
    Example: 2024-06-20T14:05:22Z

  - `data.id` (string, required)
    Unique identifier for the treatment category within the practice. Use this value when referring to the treatment category in subsequent API calls.
    Example: 4ee0fa3e-12f4-4942-9347-1702eb89ebcc

  - `data.name` (string)
    The name of the treatment category as displayed in Dentally. `null` when the category has no name. Names are not unique within a practice. The built-in category named "System Treatments" is returned like any other category.
    Example: Diagnostic Related Services

## Response 400:

  - `400` (unknown)
    Malformed Request ([ProblemDetails](https://tools.ietf.org/html/rfc7807))

## Response 400 fields (application/problem+json):

  - `type` (string)
    A URI reference [[RFC3986](https://tools.ietf.org/html/rfc3986)] that
identifies the problem type. It should provide human-readable
documentation for the problem type. When this member is not present, its
value is assumed to be "about:blank".
    Example: https://httpstatuses.io/400

  - `title` (string)
    A short, human-readable summary of the problem type. It SHOULD NOT change from occurrence to occurrence of the problem, except for purposes of localization.
    Example: Bad Request

  - `status` (integer)
    The HTTP status code.
    Example: 400

  - `detail` (string)
    A human-readable explanation specific to this occurrence of the problem.
    Example: Missing required field 'address'

  - `instance` (string)
    A URI reference that identifies the specific occurrence of the problem.  It may or may not yield further information if de-referenced.
    Example: /v2/sites

## Response 401:

  - `401` (unknown)
    Unauthorized - Provide proof of identity ([ProblemDetails](https://tools.ietf.org/html/rfc7807))

## Response 401 fields (application/problem+json):

  - `type` (string)
    A URI reference [[RFC3986](https://tools.ietf.org/html/rfc3986)] that
identifies the problem type. It should provide human-readable
documentation for the problem type. When this member is not present, its
value is assumed to be "about:blank".
    Example: https://httpstatuses.io/400

  - `title` (string)
    A short, human-readable summary of the problem type. It SHOULD NOT change from occurrence to occurrence of the problem, except for purposes of localization.
    Example: Bad Request

  - `status` (integer)
    The HTTP status code.
    Example: 400

  - `detail` (string)
    A human-readable explanation specific to this occurrence of the problem.
    Example: Missing required field 'address'

  - `instance` (string)
    A URI reference that identifies the specific occurrence of the problem.  It may or may not yield further information if de-referenced.
    Example: /v2/sites

## Response 404:

  - `404` (unknown)
    Not Found - Could not find a matching entity ([ProblemDetails](https://tools.ietf.org/html/rfc7807))

## Response 404 fields (application/problem+json):

  - `type` (string)
    A URI reference [[RFC3986](https://tools.ietf.org/html/rfc3986)] that
identifies the problem type. It should provide human-readable
documentation for the problem type. When this member is not present, its
value is assumed to be "about:blank".
    Example: https://httpstatuses.io/400

  - `title` (string)
    A short, human-readable summary of the problem type. It SHOULD NOT change from occurrence to occurrence of the problem, except for purposes of localization.
    Example: Bad Request

  - `status` (integer)
    The HTTP status code.
    Example: 400

  - `detail` (string)
    A human-readable explanation specific to this occurrence of the problem.
    Example: Missing required field 'address'

  - `instance` (string)
    A URI reference that identifies the specific occurrence of the problem.  It may or may not yield further information if de-referenced.
    Example: /v2/sites

## Response 4XX:

  - `4XX` (unknown)
    User Error ([ProblemDetails](https://tools.ietf.org/html/rfc7807))

## Response 4XX fields (application/problem+json):

  - `type` (string)
    A URI reference [[RFC3986](https://tools.ietf.org/html/rfc3986)] that
identifies the problem type. It should provide human-readable
documentation for the problem type. When this member is not present, its
value is assumed to be "about:blank".
    Example: https://httpstatuses.io/400

  - `title` (string)
    A short, human-readable summary of the problem type. It SHOULD NOT change from occurrence to occurrence of the problem, except for purposes of localization.
    Example: Bad Request

  - `status` (integer)
    The HTTP status code.
    Example: 400

  - `detail` (string)
    A human-readable explanation specific to this occurrence of the problem.
    Example: Missing required field 'address'

  - `instance` (string)
    A URI reference that identifies the specific occurrence of the problem.  It may or may not yield further information if de-referenced.
    Example: /v2/sites

## Response 5XX:

  - `5XX` (unknown)
    Server Error ([ProblemDetails](https://tools.ietf.org/html/rfc7807))

## Response 5XX fields (application/problem+json):

  - `type` (string)
    A URI reference [[RFC3986](https://tools.ietf.org/html/rfc3986)] that
identifies the problem type. It should provide human-readable
documentation for the problem type. When this member is not present, its
value is assumed to be "about:blank".
    Example: https://httpstatuses.io/400

  - `title` (string)
    A short, human-readable summary of the problem type. It SHOULD NOT change from occurrence to occurrence of the problem, except for purposes of localization.
    Example: Bad Request

  - `status` (integer)
    The HTTP status code.
    Example: 400

  - `detail` (string)
    A human-readable explanation specific to this occurrence of the problem.
    Example: Missing required field 'address'

  - `instance` (string)
    A URI reference that identifies the specific occurrence of the problem.  It may or may not yield further information if de-referenced.
    Example: /v2/sites

## Response 200 examples:

  - `Single treatment category` (unknown)
    One treatment category in the practice catalogue.

## Response 400 examples:

  - `Malformed or invalid request` (unknown)
    RFC 7807 problem details when validation fails (e.g. missing required field).

## Response 401 examples:

  - `Missing or invalid credentials` (unknown)
    RFC 7807 problem details when the caller is not authenticated.

## Response 404 examples:

  - `Resource not found` (unknown)
    RFC 7807 problem details when no resource matches the given identifier.

## Response 4XX examples:

  - `Generic client error response` (unknown)
    RFC 7807 problem details for a generic client error (e.g. conflict, unsupported media type).

## Response 5XX examples:

  - `Unexpected server error` (unknown)
    RFC 7807 problem details for an internal failure.