This code system http://hl7.org/fhir/benefit-subcategory defines the following codes:

CodeDisplayDefinition
1Medical CareMedical Care.
2SurgicalSurgical.
3ConsultationConsultation.
4Diagnostic XRayDiagnostic XRay.
5Diagnostic LabDiagnostic Lab.
14Renal SuppliesRenal Supplies excluding Dialysis.
23Diagnostic DentalDiagnostic Dental.
24PeriodonticsPeriodontics.
25RestorativeRestorative.
26EndodonticsEndodontics.
27Maxillofacilial ProstheticsMaxillofacilial Prosthetics.
28Adjunctive Dental ServicesAdjunctive Dental Services.
30Health Benefit Plan CoverageHealth Benefit Plan Coverage.
35Dental CareDental Care.
36Dental CrownsDental Crowns.
37Dental AccidentDental Accident.
49Hospital Room and BoardHospital Room and Board.
55Major MedicalMajor Medical.
56Medically Related TransportationMedically Related Transportation.
61In-vitro FertilizationIn-vitro Fertilization.
62MRI ScanMRI Scan.
63Donor ProceduresDonor Procedures such as organ harvest.
69MaternityMaternity.
76Renal DialysisRenal dialysis.
F1Medical CoverageMedical Coverage.
F3Dental CoverageDental Coverage.
F4Hearing CoverageHearing Coverage.
F6Vision CoverageVision Coverage.