Search parameters will be updated in support to the changes in the underlying structure of the IG. https://build.fhir.org/ig/HL7/davinci-pdex-formulary/search_parameters.html   PayerInsurancePlan & Formulary (InsurancePlan) Parameter Type Conf. Description Example _id token SHALL FHIR resource id of an InsurancePlan GET [base] /InsurancePlan?_id= [id] _lastUpdated date SHALL Accesses the last updated date of an InsurancePlan GET [base] /InsurancePlan?_lastUpdated= [date] identifier token SHALL Accesses the business identifier of an InsurancePlan GET [base] /InsurancePlan?identifier= [system] | [code] status token SHALL Accesses the status of an InsurancePlan GET [base] /InsurancePlan?status= [code] period date SHALL Accesses the active period of an InsurancePlan GET [base] /InsurancePlan?period= [date] type token SHALL Accesses the Type of an InsurancePlan GET [base] /InsurancePlan?type= [system] | [code] name string SHALL Accesses the name of an InsurancePlan GET [base] /InsurancePlan?name= [string] coverage-type token SHALL Accesses the coverage type of an InsurancePlan GET [base] /InsurancePlan?coverage-type= [system] | [code] formulary-coverage reference SHALL Accesses the Coverage Formulary Reference of an InsurancePlan GET [base] /InsurancePlan?formulary-coverage= [reference] coverage-area reference SHALL Search InsurancePlan by coverage location. GET [base] /InsurancePlan?coverage-area= [reference]   InsurancePlanLocation (Location) Parameter Type Conf. Description Example _id token SHALL FHIR resource id of a Location GET [base] /Location?_id= [id] _lastUpdated date SHOULD Access the last updated date of a Location GET [base] /Location?_lastUpdated= [date] address string SHOULD Access the address of a Location GET [base] /Location?address= [string] address-city string SHOULD Access the city of a Location GET [base] /Location?address-city= [string] address-state string SHOULD Access the state of a Location GET [base] /Location?address-state= [string] address-postalcode string SHOULD Access the postal code of a Location GET [base] /Location?address-postalcode= [string]   FormularyItem (Basic) Parameter Type Conf. Description Example _id token SHALL FHIR resource id of a FormularyItem GET [base] /Basic?_id= [id] _lastUpdated date SHALL Accesses the last updated date of a FormularyItem GET [base] /Basic?_lastUpdated= [date] code token SHALL Accesses the Code of a Basis resource to find a FormularyItem GET [base] /Basic?code=formulary-item subject reference SHALL Accesses the subject FormularyDrug (MedicationKnowledge) reference of a FormularyItem GET [base] /Basic?subject= [reference] status token SHALL Accesses the status of a FormularyItem GET [base] /Basic?status= [code] period date SHALL Accesses the active period of a FormularyItem GET [base] /Basic?period= [date] formulary reference SHALL Accesses the formulary reference of a FormularyItem GET [base] /Basic?formulary= [reference] pharmacy-type token SHALL Accesses the Pharmacy Network Type of a FormularyItem GET [base] /Basic?pharmacy-type= [system] | [code] drug-tier token SHALL Accesses the Drug Tier of a FormularyItem GET [base] /Basic?drug-tier= [system] | [code]   FormularyDrug (MedicationKnowledge) Parameter Type Conf. Description Example _id token SHALL FHIR resource id of a FormularyDrug GET [base] /MedicationKnowledge?_id= [id] _lastUpdated date SHALL Accesses the last updated date of a FormularyItem GET [base] /MedicationKnowledge?_lastUpdated= [date] status token SHALL Accesses the status of a FormularyDrug GET [base] /MedicationKnowledge?status= [code] code token SHALL Accesses the status of a FormularyDrug GET [base] /MedicationKnowledge?code= [system] | [code] drug-name string SHALL Accesses the Drug Name of a FormularyDrug GET [base] /MedicationKnowledge?drug-name= [string] doseform token SHOULD Accesses the dose form of a FormularyDrug GET [base] /MedicationKnowledge?doseform= [system\|code]