This code system http://hl7.org/fhir/medication-cost-category defines the following codes:

CodeDisplayDefinition
banda Band ATier A cost for this medication
bandb Band BTier B cost for this medication
<status value="active"/><experimental value="false"/><description value="Medication Cost Category Codes"/><jurisdiction><coding><system value="http://unstats.un.org/unsd/methods/m49/m49.htm"/><code value="001"/><display value="World"/></coding></jurisdiction><caseSensitive value="true"/><valueSet value="http://hl7.org/fhir/ValueSet/medication-cost-category"/><content value="complete"/><concept><code value="banda"/><display value="Band A"/><definition value="Tier A cost for this medication"/></concept><concept><code value="bandb"/><display value="Band B"/><definition value="Tier B cost for this medication"/></concept></CodeSystem>