diff --git a/hapi-fhir-base/src/main/java/ca/uhn/fhir/model/primitive/IdDt.java b/hapi-fhir-base/src/main/java/ca/uhn/fhir/model/primitive/IdDt.java
index 008b7fb3e0d..864f8e8b6e9 100644
--- a/hapi-fhir-base/src/main/java/ca/uhn/fhir/model/primitive/IdDt.java
+++ b/hapi-fhir-base/src/main/java/ca/uhn/fhir/model/primitive/IdDt.java
@@ -305,11 +305,16 @@ public class IdDt extends UriDt implements /*IPrimitiveDatatype<String>, */IIdTy
 				b.append(myResourceType);
 			}
 
-			if (b.length() > 0) {
+			if (b.length() > 0 && isNotBlank(myUnqualifiedId)) {
+				b.append('/');
+			}
+
+			if (isNotBlank(myUnqualifiedId)) {
+				b.append(myUnqualifiedId);
+			} else if (isNotBlank(myUnqualifiedVersionId)) {
 				b.append('/');
 			}
 
-			b.append(myUnqualifiedId);
 			if (isNotBlank(myUnqualifiedVersionId)) {
 				b.append('/');
 				b.append(Constants.PARAM_HISTORY);
@@ -527,7 +532,21 @@ public class IdDt extends UriDt implements /*IPrimitiveDatatype<String>, */IIdTy
 				if (typeIndex == -1) {
 					myResourceType = theValue.substring(0, idIndex);
 				} else {
-					myResourceType = theValue.substring(typeIndex + 1, idIndex);
+					if (typeIndex > 0 && '/' == theValue.charAt(typeIndex - 1)) {
+						typeIndex = theValue.indexOf('/', typeIndex + 1);
+					}
+					if (typeIndex >= idIndex) {
+						// e.g. http://example.org/foo
+						// 'foo' was the id but we're making that the resource type. Nullify the id part because we don't have an id.
+						// Also set null value to the super.setValue() and enable myHaveComponentParts so it forces getValue() to properly
+						// recreate the url
+						myResourceType = myUnqualifiedId;
+						myUnqualifiedId = null;
+						super.setValue(null);
+						myHaveComponentParts = true;
+					} else {
+						myResourceType = theValue.substring(typeIndex + 1, idIndex);
+					}
 
 					if (typeIndex > 4) {
 						myBaseUrl = theValue.substring(0, typeIndex);
diff --git a/hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/entity/ResourceLink.java b/hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/entity/ResourceLink.java
index 5209106280d..174b7d3ed81 100644
--- a/hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/entity/ResourceLink.java
+++ b/hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/entity/ResourceLink.java
@@ -197,8 +197,16 @@ public class ResourceLink implements Serializable {
 	public void setTargetResourceUrl(IIdType theTargetResourceUrl) {
 		Validate.isTrue(theTargetResourceUrl.hasBaseUrl());
 		Validate.isTrue(theTargetResourceUrl.hasResourceType());
-		Validate.isTrue(theTargetResourceUrl.hasIdPart());
-		
+
+		if (theTargetResourceUrl.hasIdPart()) {
+			// do nothing
+		} else {
+			// Must have set an url like http://example.org/something
+			// We treat 'something' as the resource type because of fix for #659. Prior to #659 fix, 'something' was
+			// treated as the id and 'example.org' was treated as the resource type
+			// TODO: log a warning?
+		}
+
 		myTargetResourceType = theTargetResourceUrl.getResourceType();
 		myTargetResourceUrl = theTargetResourceUrl.getValue();
 	}
diff --git a/hapi-fhir-structures-dstu2.1/src/main/java/org/hl7/fhir/dstu2016may/model/IdType.java b/hapi-fhir-structures-dstu2.1/src/main/java/org/hl7/fhir/dstu2016may/model/IdType.java
index 8a6df569886..f5e4ee31a06 100644
--- a/hapi-fhir-structures-dstu2.1/src/main/java/org/hl7/fhir/dstu2016may/model/IdType.java
+++ b/hapi-fhir-structures-dstu2.1/src/main/java/org/hl7/fhir/dstu2016may/model/IdType.java
@@ -358,11 +358,16 @@ public final class IdType extends UriType implements IPrimitiveType<String>, IId
         b.append(myResourceType);
       }
 
-      if (b.length() > 0) {
+      if (b.length() > 0 && isNotBlank(myUnqualifiedId)) {
+        b.append('/');
+      }
+
+      if (isNotBlank(myUnqualifiedId)) {
+        b.append(myUnqualifiedId);
+      } else if (isNotBlank(myUnqualifiedVersionId)) {
         b.append('/');
       }
 
-      b.append(myUnqualifiedId);
       if (isNotBlank(myUnqualifiedVersionId)) {
         b.append('/');
         b.append("_history");
@@ -554,7 +559,21 @@ public final class IdType extends UriType implements IPrimitiveType<String>, IId
         if (typeIndex == -1) {
           myResourceType = theValue.substring(0, idIndex);
         } else {
-          myResourceType = theValue.substring(typeIndex + 1, idIndex);
+          if (typeIndex > 0 && '/' == theValue.charAt(typeIndex - 1)) {
+            typeIndex = theValue.indexOf('/', typeIndex + 1);
+          }
+          if (typeIndex >= idIndex) {
+            // e.g. http://example.org/foo
+            // 'foo' was the id but we're making that the resource type. Nullify the id part because we don't have an id.
+            // Also set null value to the super.setValue() and enable myHaveComponentParts so it forces getValue() to properly
+            // recreate the url
+            myResourceType = myUnqualifiedId;
+            myUnqualifiedId = null;
+            super.setValue(null);
+            myHaveComponentParts = true;
+          } else {
+            myResourceType = theValue.substring(typeIndex + 1, idIndex);
+          }
 
           if (typeIndex > 4) {
             myBaseUrl = theValue.substring(0, typeIndex);
diff --git a/hapi-fhir-structures-dstu3/src/main/java/org/hl7/fhir/dstu3/model/IdType.java b/hapi-fhir-structures-dstu3/src/main/java/org/hl7/fhir/dstu3/model/IdType.java
index 02535643be3..530d9dfa284 100644
--- a/hapi-fhir-structures-dstu3/src/main/java/org/hl7/fhir/dstu3/model/IdType.java
+++ b/hapi-fhir-structures-dstu3/src/main/java/org/hl7/fhir/dstu3/model/IdType.java
@@ -357,11 +357,16 @@ public final class IdType extends UriType implements IPrimitiveType<String>, IId
         b.append(myResourceType);
       }
 
-      if (b.length() > 0) {
+      if (b.length() > 0 && isNotBlank(myUnqualifiedId)) {
+        b.append('/');
+      }
+
+      if (isNotBlank(myUnqualifiedId)) {
+        b.append(myUnqualifiedId);
+      } else if (isNotBlank(myUnqualifiedVersionId)) {
         b.append('/');
       }
 
-      b.append(myUnqualifiedId);
       if (isNotBlank(myUnqualifiedVersionId)) {
         b.append('/');
         b.append("_history");
@@ -553,7 +558,21 @@ public final class IdType extends UriType implements IPrimitiveType<String>, IId
         if (typeIndex == -1) {
           myResourceType = theValue.substring(0, idIndex);
         } else {
-          myResourceType = theValue.substring(typeIndex + 1, idIndex);
+          if (typeIndex > 0 && '/' == theValue.charAt(typeIndex - 1)) {
+            typeIndex = theValue.indexOf('/', typeIndex + 1);
+          }
+          if (typeIndex >= idIndex) {
+            // e.g. http://example.org/foo
+            // 'foo' was the id but we're making that the resource type. Nullify the id part because we don't have an id.
+            // Also set null value to the super.setValue() and enable myHaveComponentParts so it forces getValue() to properly
+            // recreate the url
+            myResourceType = myUnqualifiedId;
+            myUnqualifiedId = null;
+            super.setValue(null);
+            myHaveComponentParts = true;
+          } else {
+            myResourceType = theValue.substring(typeIndex + 1, idIndex);
+          }
 
           if (typeIndex > 4) {
             myBaseUrl = theValue.substring(0, typeIndex);
diff --git a/hapi-fhir-structures-hl7org-dstu2/src/main/java/org/hl7/fhir/instance/model/IdType.java b/hapi-fhir-structures-hl7org-dstu2/src/main/java/org/hl7/fhir/instance/model/IdType.java
index 5239236c4ec..06b82519282 100644
--- a/hapi-fhir-structures-hl7org-dstu2/src/main/java/org/hl7/fhir/instance/model/IdType.java
+++ b/hapi-fhir-structures-hl7org-dstu2/src/main/java/org/hl7/fhir/instance/model/IdType.java
@@ -384,11 +384,16 @@ public final class IdType extends UriType implements IPrimitiveType<String>, IId
         b.append(myResourceType);
       }
 
-      if (b.length() > 0) {
+      if (b.length() > 0 && isNotBlank(myUnqualifiedId)) {
+        b.append('/');
+      }
+
+      if (isNotBlank(myUnqualifiedId)) {
+        b.append(myUnqualifiedId);
+      } else if (isNotBlank(myUnqualifiedVersionId)) {
         b.append('/');
       }
 
-      b.append(myUnqualifiedId);
       if (isNotBlank(myUnqualifiedVersionId)) {
         b.append('/');
         b.append("_history");
@@ -571,7 +576,21 @@ public final class IdType extends UriType implements IPrimitiveType<String>, IId
         if (typeIndex == -1) {
           myResourceType = theValue.substring(0, idIndex);
         } else {
-          myResourceType = theValue.substring(typeIndex + 1, idIndex);
+          if (typeIndex > 0 && '/' == theValue.charAt(typeIndex - 1)) {
+            typeIndex = theValue.indexOf('/', typeIndex + 1);
+          }
+          if (typeIndex >= idIndex) {
+            // e.g. http://example.org/foo
+            // 'foo' was the id but we're making that the resource type. Nullify the id part because we don't have an id.
+            // Also set null value to the super.setValue() and enable myHaveComponentParts so it forces getValue() to properly
+            // recreate the url
+            myResourceType = myUnqualifiedId;
+            myUnqualifiedId = null;
+            super.setValue(null);
+            myHaveComponentParts = true;
+          } else {
+            myResourceType = theValue.substring(typeIndex + 1, idIndex);
+          }
 
           if (typeIndex > 4) {
             myBaseUrl = theValue.substring(0, typeIndex);