This code system http://terminology.hl7.org/CodeSystem/medicationrequest-admin-location defines the following codes:
CodeDisplayDefinition
inpatient Inpatient Includes requests for medications to be administered or consumed in an inpatient or acute care setting
outpatient Outpatient Includes requests for medications to be administered or consumed in an outpatient setting (for example, Emergency Department, Outpatient Clinic, Outpatient Surgery, Doctor's office)
community Community Includes requests for medications to be administered or consumed by the patient in their home (this would include long term care or nursing homes, hospices, etc.)