| id | 0..1 | string | Logical id of this artifact |
| meta | 0..1 | Meta | Metadata about the resource |
| implicitRules | 0..1 | uri | A set of rules under which this content was created |
| language | 0..1 | code | Language of the resource content |
| text | 0..1 | Narrative | Text summary of the resource, for human interpretation |
| contained | 0..* | Resource | Contained, inline Resources |
| extension | 0..* | Extension | Additional content defined by implementations |
| modifierExtension | 0..* | Extension | Extensions that cannot be ignored |
| url | 0..1 | uri | Canonical identifier for this activity definition, represented as a URI (globally unique) |
| identifier | 0..* | Identifier | Additional identifier for the activity definition |
| version | 0..1 | string | Business version of the activity definition |
| name | 0..1 | string | Name for this activity definition (computer friendly) |
| title | 0..1 | string | Name for this activity definition (human friendly) |
| subtitle | 0..1 | string | Subordinate title of the activity definition |
| status | 1..1 | code | draft | active | retired | unknown |
| experimental | 0..1 | boolean | For testing purposes, not real usage |
| subject[x] | 0..1 | CodeableConcept | Type of individual the activity definition is intended for |
| date | 0..1 | dateTime | Date last changed |
| publisher | 0..1 | string | Name of the publisher (organization or individual) |
| contact | 0..* | ContactDetail | Contact details for the publisher |
| description | 0..1 | markdown | Natural language description of the activity definition |
| useContext | 0..* | UsageContext | The context that the content is intended to support |
| jurisdiction | 0..* | CodeableConcept | Intended jurisdiction for activity definition (if applicable) |
| purpose | 0..1 | markdown | Why this activity definition is defined |
| usage | 0..1 | string | Describes the clinical usage of the activity definition |
| copyright | 0..1 | markdown | Use and/or publishing restrictions |
| approvalDate | 0..1 | date | When the activity definition was approved by publisher |
| lastReviewDate | 0..1 | date | When the activity definition was last reviewed |
| effectivePeriod | 0..1 | Period | When the activity definition is expected to be used |
| topic | 0..* | CodeableConcept | E.g. Education, Treatment, Assessment, etc. |
| author | 0..* | ContactDetail | Who authored the content |
| editor | 0..* | ContactDetail | Who edited the content |
| reviewer | 0..* | ContactDetail | Who reviewed the content |
| endorser | 0..* | ContactDetail | Who endorsed the content |
| relatedArtifact | 0..* | RelatedArtifact | Additional documentation, citations, etc. |
| library | 0..* | canonical | Logic used by the activity definition |
| kind | 0..1 | code | Kind of resource |
| profile | 0..1 | canonical | What profile the resource needs to conform to |
| code | 0..1 | CodeableConcept | Detail type of activity |
| intent | 0..1 | code | proposal | plan | directive | order | original-order | reflex-order | filler-order | instance-order | option |
| priority | 0..1 | code | routine | urgent | asap | stat |
| doNotPerform | 0..1 | boolean | True if the activity should not be performed |
| timing[x] | 0..1 | Timing | When activity is to occur |
| location | 0..1 | Reference | Where it should happen |
| participant | 0..* | BackboneElement | Who should participate in the action |
| product[x] | 0..1 | Reference | What's administered/supplied |
| quantity | 0..1 | Quantity | How much is administered/consumed/supplied |
| dosage | 0..* | Dosage | Detailed dosage instructions |
| bodySite | 0..* | CodeableConcept | What part of body to perform on |
| specimenRequirement | 0..* | Reference | What specimens are required to perform this action |
| observationRequirement | 0..* | Reference | What observations are required to perform this action |
| observationResultRequirement | 0..* | Reference | What observations must be produced by this action |
| transform | 0..1 | canonical | Transform to apply the template |
| dynamicValue | 0..* | BackboneElement | Dynamic aspects of the definition |