FHIR Developer Skill Quick Reference HTTP Status Codes | Code | When to Use | |------|-------------| | | Successful read, update, or search | | | Successful create (include header) | | | Successful delete | | | Malformed JSON, wrong resourceType | | | Missing, expired, revoked, or malformed token (RFC 6750) | | | Valid token but insufficient scopes | | | Resource doesn't exist | | | If-Match ETag mismatch (NOT 400!) | | | Missing required fields, invalid enum values, business rule violations | Required Fields by Resource (FHIR R4) | Resource | Required Fields | Everything Else | |----------|-…