Add broad Medicare enrollment targets to the healthcare fiscal surface

Context

The current healthcare target surface includes Medicare Part B premium income, and #169 tracks a payer-count shortfall for that amount target. It does not yet include broader Medicare enrollment targets.

That leaves several important Medicare surfaces absent from release-over-release healthcare diagnostics: Part A enrollment, Part B enrollment, Medicare Advantage, Part D, dual eligibles, and LIS.

Goal

Add a Medicare enrollment target cluster, or explicitly document which Medicare enrollment surfaces are not yet available to Populace.

Suggested implementation

• Inventory CMS Medicare enrollment source artifacts available to Ledger/Populace.
• Add target roles for supported enrollment concepts, especially:
  • Medicare Part A enrollment
  • Medicare Part B enrollment
  • Medicare Advantage enrollment
  • Medicare Part D enrollment
  • dual eligibles
  • LIS recipients
• Prefer national and state targets where source geography supports them.
• Keep enrollment targets separate from the existing Part B premium-income target so diagnostics can identify payer-count vs amount-per-payer problems.

Acceptance criteria

• Release artifacts expose Medicare enrollment targets where source support exists.
• Metadata names the target role and source concept for each Medicare enrollment surface.
• Tests cover target mapping and profile coverage for the Medicare enrollment cluster.
• #169 can use the new enrollment/payer diagnostics, or links back here if the broader enrollment surface is a prerequisite.

Related:

• Medicare Part B premium payer-count diagnostic: #169

Start by inventorying the CMS Medicare enrollment source artifacts available to Ledger/Populace, then trace how release artifacts, target metadata, and profile coverage are represented. Map supported Part A, Part B, Medicare Advantage, Part D, dual-eligible, and LIS concepts at national or state geography where available. Done means supported enrollment targets are exposed with source-concept metadata and covered by mapping and profile tests, or unavailable surfaces are explicitly documented.