
**Example Usage Scenarios:**

The following are example usage scenarios for this profile:

-   Query for a specific patient encounter
-   Query for recent patient encounters
-   [Record or update] an encounter

### Mandatory and Must Support Data Elements

The following data elements must always be present ([Mandatory] definition) or must be supported if the data is present in the sending system ([Must Support] definition). They are presented below in a simple human-readable explanation. Profile specific guidance and examples are provided as well. The [Formal Views] below provides the formal summary, definitions, and terminology requirements.

**Each Encounter Must Have:**

1. A status
1. A classification such as inpatient, outpatient, or emergency
1. An encounter type
1. A patient

**Each Encounter Must Support:**

1. A timestamp when the resource last changed<sup>1</sup>
1. An encounter identifier
1. Providers involved in the encounter
1. When the encounter occurred
1. Reason for the visit
1. The discharge disposition
1. Where the encounter occurred

{% include additional-requirements-intro.md type="Patient" plural="true" %}

1. Interpreter Needed flag<sup>2</sup>

<sup>1,2</sup> see guidance below

### Profile Specific Implementation Guidance

This section provides detailed implementation guidance for the US Core Profile to support implementation and certification.

* To search for an encounter diagnosis, query for Condition resources that reference the Encounter of interest and have a category of `encounter-diagnosis`.   An example search is shown in the [Condition Quick Start] section.
* The Encounter resource can represent a reason using a code with `Encounter.reasonCode` or a reference with `Encounter.reasonReference` to  Condition or other resources.
   * Although both are marked as Must Support, Servers are not required to support both a code and a reference, but they **SHALL** support *at least one* of these elements.<sup>[§][CONF-0375]</sup>
   * The Client application **SHALL** support both elements.<sup>[§][CONF-0376],[§][CONF-0377]</sup>
   * If `Encounter.reasonReference` references an Observation, it **SHOULD** conform to a US Core Observation if applicable.<sup>[§][CONF-0378]</sup> For example, a laboratory result **SHOULD** conform to the [US Core Laboratory Result Observation Profile].
* This profile supports *where the encounter occurred*.  The location address can be represented by the Location referenced by `Encounter.location.location` or indirectly through the Organization referenced by `Encounter.serviceProvider`.
  * Although both are marked as Must Support, Servers are not required to support both `Encounter.location.location` and `Encounter.serviceProvider`, but they **SHALL** support *at least one* of these elements.<sup>[§][CONF-0379]</sup>
  * The Client application **SHALL** support both elements.<sup>[§][CONF-0380],[§][CONF-0381]</sup>

{% include encounter-location.md %}

- <sup>2</sup>Servers **SHOULD** and Certifying Systems **SHALL** use the [US Core Interpreter Needed Extension] on this profile or the [US Core Patient Profile] to communicate whether a patient needs an interpreter.<sup>[§][CONF-0851],[§][CONF-0910]</sup>
  -  Although the extension is marked as an *Additional USCDI Requirements* on both US Core Patient and US Core Encounter Profiles, Certifying Systems are not required to support the extension on both profiles, but **SHALL** support the extension on at least one.<sup>[§][CONF-0840]</sup> The certifying Client application **SHALL** support the extension on both profiles.<sup>[§][CONF-0886]</sup>
  - Systems **SHOULD** designate the patient's preferred language in the `Patient.communication.preferred` element.<sup>[§][CONF-0855]</sup>

- <sup>1</sup>See the US Core General Guidance page for [Searching Using lastUpdated]. Updates to `.meta.lastUpdated` **SHOULD** reflect:
  - New encounters/visits<sup>[§][CONF-0385]</sup>
  - Changes in the status of encounters, including events that trigger the same status (e.g., in-progress → in-progress).<sup>[§][CONF-0386]</sup> These status changes correspond to events that can initiate [HL7 V2] ADT messages.

{% include link-list.md %}
