diff --git a/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/conv30_50/resources30_50/ImplementationGuide30_50.java b/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/conv30_50/resources30_50/ImplementationGuide30_50.java
index e657fdd2e..b26c0f7cd 100644
--- a/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/conv30_50/resources30_50/ImplementationGuide30_50.java
+++ b/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/conv30_50/resources30_50/ImplementationGuide30_50.java
@@ -22,10 +22,10 @@ import org.hl7.fhir.r4.model.Extension;
 import org.hl7.fhir.r5.model.CanonicalType;
 import org.hl7.fhir.r5.model.Enumeration;
 
-static final String EXT_IG_DEFINITION_RESOURCE_PROFILE = "http://hl7.org/fhir/5.0/StructureDefinition/extension-ImplementationGuide.definition.resource.profile";
-
 public class ImplementationGuide30_50 {
 
+  static final String EXT_IG_DEFINITION_RESOURCE_PROFILE = "http://hl7.org/fhir/5.0/StructureDefinition/extension-ImplementationGuide.definition.resource.profile";
+
   public static org.hl7.fhir.dstu3.model.ImplementationGuide convertImplementationGuide(org.hl7.fhir.r5.model.ImplementationGuide src) throws FHIRException {
     if (src == null)
       return null;
@@ -211,8 +211,8 @@ public class ImplementationGuide30_50 {
       tgt.setExampleFor(Reference30_50.convertCanonicalToReference(src.getProfile().get(0)));
       tgt.setExample(true);
       if (src.getProfile().size() > 1) {
-        for (CanonicalType p: src.getProfile().subList(1, src.getProfile().size()-1)) {
-          tgt.addExtension(EXT_IG_DEFINITION_RESOURCE_PROFILE, Canonical30_50.convertCanonical(p));
+        for (CanonicalType p: src.getProfile().subList(1, src.getProfile().size())) {
+          tgt.addExtension(EXT_IG_DEFINITION_RESOURCE_PROFILE, Reference30_50.convertCanonicalToReference(p));
         }
       }
     } else if (src.hasIsExample())
@@ -234,8 +234,8 @@ public class ImplementationGuide30_50 {
       return null;
     org.hl7.fhir.r5.model.ImplementationGuide.ImplementationGuideDefinitionResourceComponent tgt = new org.hl7.fhir.r5.model.ImplementationGuide.ImplementationGuideDefinitionResourceComponent();
     ConversionContext30_50.INSTANCE.getVersionConvertor_30_50().copyBackboneElement(src,tgt);
-    for (Extension ext: src.getExtensionsByUrl(EXT_IG_DEFINITION_RESOURCE_PROFILE)) {
-      tgt.getProfile().add(Canonical30_50.convertCanonical((org.hl7.fhir.r3.model.CanonicalType)ext.getValue()));
+    for (org.hl7.fhir.dstu3.model.Extension ext: src.getExtensionsByUrl(EXT_IG_DEFINITION_RESOURCE_PROFILE)) {
+      tgt.getProfile().add(Reference30_50.convertReferenceToCanonical((org.hl7.fhir.dstu3.model.Reference)ext.getValue()));
     }
     if (src.hasExampleFor()) {
       tgt.getProfile().add(Reference30_50.convertReferenceToCanonical(src.getExampleFor()));
diff --git a/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/conv40_50/resources40_50/ImplementationGuide40_50.java b/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/conv40_50/resources40_50/ImplementationGuide40_50.java
index d0e8d2bfd..6aa82d66a 100644
--- a/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/conv40_50/resources40_50/ImplementationGuide40_50.java
+++ b/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/conv40_50/resources40_50/ImplementationGuide40_50.java
@@ -350,7 +350,7 @@ public class ImplementationGuide40_50 {
       tgt.setExample(ConversionContext40_50.INSTANCE.getVersionConvertor_40_50().convertType(src.getProfile().get(0)));
     }
     if (src.getProfile().size() > 1) {
-      for (CanonicalType p: src.getProfile().subList(1, src.getProfile().size()-1)) {
+      for (CanonicalType p: src.getProfile().subList(1, src.getProfile().size())) {
         tgt.addExtension(EXT_IG_DEFINITION_RESOURCE_PROFILE, Canonical40_50.convertCanonical(p));
       }
     }
diff --git a/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/conv43_50/resources43_50/ImplementationGuide43_50.java b/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/conv43_50/resources43_50/ImplementationGuide43_50.java
index d69d5549f..7e6999aee 100644
--- a/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/conv43_50/resources43_50/ImplementationGuide43_50.java
+++ b/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/conv43_50/resources43_50/ImplementationGuide43_50.java
@@ -320,8 +320,8 @@ public class ImplementationGuide43_50 {
       tgt.setIsExample(true);
       tgt.getProfile().add(Canonical43_50.convertCanonical(src.getExampleCanonicalType()));
     }
-    for (Extension ext: src.getExtensionsByUrl(EXT_IG_DEFINITION_RESOURCE_PROFILE)) {
-      tgt.getProfile().add(Canonical43_50.convertCanonical((org.hl7.fhir.r43.model.CanonicalType)ext.getValue()));
+    for (org.hl7.fhir.r4b.model.Extension ext: src.getExtensionsByUrl(EXT_IG_DEFINITION_RESOURCE_PROFILE)) {
+      tgt.getProfile().add(Canonical43_50.convertCanonical((org.hl7.fhir.r4b.model.CanonicalType)ext.getValue()));
     }
     if (src.hasGroupingId())
       tgt.setGroupingIdElement(Id43_50.convertId(src.getGroupingIdElement()));
@@ -347,7 +347,7 @@ public class ImplementationGuide43_50 {
     if (src.hasProfile())
       tgt.setExample(ConversionContext43_50.INSTANCE.getVersionConvertor_43_50().convertType(src.getProfile().get(0)));
     if (src.getProfile().size() > 1) {
-      for (CanonicalType p: src.getProfile().subList(1, src.getProfile().size()-1)) {
+      for (CanonicalType p: src.getProfile().subList(1, src.getProfile().size())) {
         tgt.addExtension(EXT_IG_DEFINITION_RESOURCE_PROFILE, Canonical43_50.convertCanonical(p));
       }
     }
diff --git a/org.hl7.fhir.convertors/src/test/java/org/hl7/fhir/convertors/conv40_50/ImplementationGuide40_50Test.java b/org.hl7.fhir.convertors/src/test/java/org/hl7/fhir/convertors/conv40_50/ImplementationGuide40_50Test.java
index df5919c64..6d71403d4 100644
--- a/org.hl7.fhir.convertors/src/test/java/org/hl7/fhir/convertors/conv40_50/ImplementationGuide40_50Test.java
+++ b/org.hl7.fhir.convertors/src/test/java/org/hl7/fhir/convertors/conv40_50/ImplementationGuide40_50Test.java
@@ -36,6 +36,16 @@ public class ImplementationGuide40_50Test {
 
   }
 
+  @Test
+  public void testRoundTripProfiles() throws IOException {
+    ImplementationGuide r5_actual = getR5ImplementationGuide();
+
+    org.hl7.fhir.r4.model.ImplementationGuide converted = (org.hl7.fhir.r4.model.ImplementationGuide) VersionConvertorFactory_40_50.convertResource(r5_actual);
+    ImplementationGuide r5_converted = (ImplementationGuide) VersionConvertorFactory_40_50.convertResource(converted);
+
+    assertEquals(r5_actual.getDefinition().getResourceFirstRep().getProfile().size(), r5_converted.getDefinition().getResourceFirstRep().getProfile().size());
+  }
+
   private ImplementationGuide getR5ImplementationGuide() throws IOException {
     ImplementationGuide r5_actual;
     InputStream r5_stream = this.getClass().getResourceAsStream("/implementation_guide_50.json");
diff --git a/org.hl7.fhir.convertors/src/test/resources/implementation_guide_50.json b/org.hl7.fhir.convertors/src/test/resources/implementation_guide_50.json
index 85e113f2f..f86eb441a 100644
--- a/org.hl7.fhir.convertors/src/test/resources/implementation_guide_50.json
+++ b/org.hl7.fhir.convertors/src/test/resources/implementation_guide_50.json
@@ -75,7 +75,8 @@
         "name": "Test Example",
         "description": "A test example to show how an implementation guide works",
         "profile": [
-          "http://hl7.org/fhir/us/core/StructureDefinition/patient"
+          "http://hl7.org/fhir/us/core/StructureDefinition/patient",
+          "http://hl7.org/fhir/uv/ips/StructureDefinition/Patient-uv-ips"
         ]
       }
     ],