Care Plan Service — Domain Model

Status: populated Owner: TBD Last updated: 2026-04-18 Companion: Service Template · 03 platform-services · 02 DDD

Aggregates

CarePlan (Root Aggregate)

Invariants:

• Must reference a valid patientId from registration-service.
• Only roles care_plan:write or care_plan:admin may create or update.
• Plans in completed or revoked status are immutable (read-only).
• status transitions follow the state machine below — no skipping.
• Optimistic concurrency: version increments atomically; stale writes return 409 Conflict.
• Maximum 50 active goals and 100 activities per plan (configurable per tenant).

Status State Machine:

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CarePlanGoal (Entity, owned by CarePlan)

Invariants:

• Belongs to exactly one CarePlan.
• dueAt must be in the future at creation (warning if not — not hard block in MVP).
• Status transitions: proposed → accepted → in_progress → achieved | cancelled | on_hold.
• A goal is overdue when dueAt < now and status is not achieved or cancelled.

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CarePlanActivity (Entity, owned by CarePlan)

Invariants:

• Belongs to exactly one CarePlan.
• May reference a ServiceRequest in orders-service by external ID (not FK).
• Completion requires completionNote if tenant policy mandates it.
• Status transitions: not_started → in_progress → completed | cancelled.

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CareTeamMember (Entity, owned by CarePlan)

• References practitionerId from provider-directory-service (soft reference, not FK).
• Has a role coded as CodeableConcept (e.g., primary care provider, care coordinator, specialist).
• Effective period: effectiveFrom (required), effectiveTo? (optional — open-ended membership).

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Domain Events

Event type (NATS subject)	Trigger	Key payload fields
care_plan.care_plan.created.v1	New CarePlan persisted	carePlanId, patientId, tenantId, status, title
care_plan.care_plan.updated.v1	Status or field changed	carePlanId, patientId, previousStatus, newStatus, version
care_plan.care_plan.reviewed.v1	Review workflow completed	carePlanId, reviewedBy, reviewedAt, nextReviewDue?
care_plan.goal.created.v1	Goal added to plan	goalId, carePlanId, patientId, status
care_plan.goal.updated.v1	Goal status or target changed	goalId, carePlanId, previousStatus, newStatus
care_plan.activity.created.v1	Activity added	activityId, carePlanId, assigneeId?, status
care_plan.activity.completed.v1	Activity marked complete	activityId, carePlanId, completedAt, completionNote?
care_plan.care_team.updated.v1	Team membership changed	carePlanId, addedMemberIds[], removedMemberIds[]

All events use CloudEvents v1.0 envelope with tenantid, actorid, correlationid extensions.

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Value Objects

Value object	Type definition
CarePlanStatus	enum { draft, active, on_hold, completed, revoked }
GoalStatus	enum { proposed, accepted, in_progress, achieved, cancelled, on_hold }
ActivityStatus	enum { not_started, in_progress, completed, cancelled }
CodeableConcept	{ coding: Coding[], text?: string }
Coding	{ system: string, code: string, display?: string }
TargetDetail	{ measure?: CodeableConcept, detailQuantity?: Quantity, dueDate?: string }
Quantity	{ value: number, unit: string, system?: string, code?: string }
TenantId	Branded<string, 'TenantId'>
CarePlanId	Branded<string, 'CarePlanId'> — ULID with prefix cp_
GoalId	Branded<string, 'GoalId'> — ULID with prefix cpg_
ActivityId	Branded<string, 'ActivityId'> — ULID with prefix cpa_
CareTeamMemberId	Branded<string, 'CareTeamMemberId'> — ULID with prefix ctm_

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Ubiquitous Language

Term	Definition
CarePlan	A structured longitudinal plan of care for a patient covering goals, interventions, and responsible team members across one or more conditions
Goal	A measurable health objective linked to a care plan, with a coded target, numeric target, or free-text description, and a due date
Activity / Intervention	A specific action (education, referral, procedure, monitoring, medication adherence) assigned to a care team member
CareTeam	The set of practitioners responsible for a patient's care plan; each member has a role and effective period
Review	A formal reassessment of a care plan that updates lastReviewedAt and may change status, goals, or activities
Version	Monotonic integer on the CarePlan aggregate used for optimistic concurrency; every mutation increments it
Overdue goal	A goal whose dueAt is past the current date and status is not achieved or cancelled
Closed plan	A plan in completed or revoked status — immutable, read-only, permanently visible
Activation	Transitioning a plan from draft to active, making it operationally visible to the care team