This code system http://terminology.hl7.org/CodeSystem/ex-USCLS defines the following codes:

CodeDisplayDefinition
1101 Exam, comp, primaryExam, comp, primary
1102 Exam, comp, mixedExam, comp, mixed
1103 Exam, comp, permanentExam, comp, permanent
1201 Exam, recallExam, recall
1205 Exam, emergencyExam, emergency
2101 Radiograph, series (12)Radiograph, series (12)
2102 Radiograph, series (16)Radiograph, series (16)
2141 Radiograph, bitewingRadiograph, bitewing
2601 Radiograph, panoramicRadiograph, panoramic
11101 Polishing, 1 unitPolishing, 1 unit
11102 Polishing, 2 unitPolishing, 2 unit
11103 Polishing, 3 unitPolishing, 3 unit
11104 Polishing, 4 unitPolishing, 4 unit
21211 Amalgam, 1 surfaceAmalgam, 1 surface
21212 Amalgam, 2 surfaceAmalgam, 2 surface
27211 Crown, PFMCrown, PFM
67211 Maryland BridgeMaryland Bridge
99111 Lab, commercialLab, commercial
99333 Lab, in officeLab, in office
99555 ExpenseExpense
 <status value="draft"/> <experimental value="false"/> <date value="2022-11-04T18:21:49-06:00"/> <publisher value="FHIR Project team"/> <contact> <telecom> <system value="url"/> <value value="http://hl7.org/fhir"/> </telecom> </contact> <description value="This value set includes a smattering of USCLS codes."/> <copyright value="This is an example set."/> <caseSensitive value="true"/> <valueSet value="http://terminology.hl7.org/ValueSet/service-uscls"/> <content value="complete"/> <concept> <code value="1101"/> <display value="Exam, comp, primary"/> <definition value="Exam, comp, primary"/> </concept> <concept> <code value="1102"/> <display value="Exam, comp, mixed"/> <definition value="Exam, comp, mixed"/> </concept> <concept> <code value="1103"/> <display value="Exam, comp, permanent"/> <definition value="Exam, comp, permanent"/> </concept> <concept> <code value="1201"/> <display value="Exam, recall"/> <definition value="Exam, recall"/> </concept> <concept> <code value="1205"/> <display value="Exam, emergency"/> <definition value="Exam, emergency"/> </concept> <concept> <code value="2101"/> <display value="Radiograph, series (12)"/> <definition value="Radiograph, series (12)"/> </concept> <concept> <code value="2102"/> <display value="Radiograph, series (16)"/> <definition value="Radiograph, series (16)"/> </concept> <concept> <code value="2141"/> <display value="Radiograph, bitewing"/> <definition value="Radiograph, bitewing"/> </concept> <concept> <code value="2601"/> <display value="Radiograph, panoramic"/> <definition value="Radiograph, panoramic"/> </concept> <concept> <code value="11101"/> <display value="Polishing, 1 unit"/> <definition value="Polishing, 1 unit"/> </concept> <concept> <code value="11102"/> <display value="Polishing, 2 unit"/> <definition value="Polishing, 2 unit"/> </concept> <concept> <code value="11103"/> <display value="Polishing, 3 unit"/> <definition value="Polishing, 3 unit"/> </concept> <concept> <code value="11104"/> <display value="Polishing, 4 unit"/> <definition value="Polishing, 4 unit"/> </concept> <concept> <code value="21211"/> <display value="Amalgam, 1 surface"/> <definition value="Amalgam, 1 surface"/> </concept> <concept> <code value="21212"/> <display value="Amalgam, 2 surface"/> <definition value="Amalgam, 2 surface"/> </concept> <concept> <code value="27211"/> <display value="Crown, PFM"/> <definition value="Crown, PFM"/> </concept> <concept> <code value="67211"/> <display value="Maryland Bridge"/> <definition value="Maryland Bridge"/> </concept> <concept> <code value="99111"/> <display value="Lab, commercial"/> <definition value="Lab, commercial"/> </concept> <concept> <code value="99333"/> <display value="Lab, in office"/> <definition value="Lab, in office"/> </concept> <concept> <code value="99555"/> <display value="Expense"/> <definition value="Expense"/> </concept> </CodeSystem>