Rating Areas

What Are Rating Areas?

Rating areas are geographic regions defined by each state where insurance premiums are the same for all residents. A single state may have 1 to 67 rating areas. The rating area determines which plans are available and at what price.

ZIP Code Resolution

The Opelyx API resolves ZIP codes to rating areas automatically. When you search for plans by ZIP code, the API:

1. Looks up the ZIP code in the zip_rating_area table
2. Determines the state, county, and rating area
3. Filters plans to those available in that rating area
4. Returns premiums from the matching rate records

The ZIP Lookup Endpoint

Use GET /v1/health/zip/:zip to see what a ZIP code resolves to:

{
  "zip_code": "90210",
  "state_code": "CA",
  "county_name": "Los Angeles",
  "rating_area_id": "Rating Area 16",
  "source": "d1"
}

Caution

Rating area IDs are not unique across states. “Rating Area 43” exists in both Florida and South Carolina. Always filter by state_code alongside rating_area_id when working with rating areas directly.

Cross-State ZIP Codes

Some ZIP codes span multiple counties or even multiple rating areas. When a ZIP code maps to multiple rating areas, the API returns all matches and selects plans from the primary (most populous) area.

Data Sources

• FFM states (30): CMS PUF zip_rating_area table
• SBM states (21): State exchange crosswalk data, curated per-state