diff --git a/fixtures/condition_with_contained_patient.json b/fixtures/condition_with_contained_patient.json
index 51aebe7a..311410a0 100644
--- a/fixtures/condition_with_contained_patient.json
+++ b/fixtures/condition_with_contained_patient.json
@@ -15,6 +15,9 @@
       }],
       "gender": "male",
       "birthDate": "1950-09-02",
+      "managingOrganization": {
+        "reference": "Organization/1"
+      },
       "extension":[
         {
            "url":"http://hl7.org/fhir/StructureDefinition/us-core-race",
diff --git a/models/domainresource.go b/models/domainresource.go
index b3a62609..902deed1 100644
--- a/models/domainresource.go
+++ b/models/domainresource.go
@@ -26,10 +26,34 @@
 
 package models
 
+import (
+	"gopkg.in/mgo.v2/bson"
+)
+
+type ContainedResources []interface{}
+
 type DomainResource struct {
 	Resource          `bson:",inline"`
-	Text              *Narrative    `bson:"text,omitempty" json:"text,omitempty"`
-	Contained         []interface{} `bson:"contained,omitempty" json:"contained,omitempty"`
-	Extension         []Extension   `bson:"extension,omitempty" json:"extension,omitempty"`
-	ModifierExtension []Extension   `bson:"modifierExtension,omitempty" json:"modifierExtension,omitempty"`
+	Text              *Narrative         `bson:"text,omitempty" json:"text,omitempty"`
+	Contained         ContainedResources `bson:"contained,omitempty" json:"contained,omitempty"`
+	Extension         []Extension        `bson:"extension,omitempty" json:"extension,omitempty"`
+	ModifierExtension []Extension        `bson:"modifierExtension,omitempty" json:"modifierExtension,omitempty"`
+}
+
+// Convert contained resources from map[string]interfac{} to specific types.
+// Custom marshalling methods on those types will then hide internal fields
+// like @context and referenceid.
+func (x *ContainedResources) SetBSON(raw bson.Raw) (err error) {
+
+	// alias type to avoid infinite loop when calling Unmarshal
+	type containedResources ContainedResources
+	x2 := (*containedResources)(x)
+	if err = raw.Unmarshal(x2); err == nil {
+		if x != nil {
+			for i := range *x {
+				(*x)[i] = BSONMapToResource((*x)[i].(bson.M), true)
+			}
+		}
+	}
+	return
 }
diff --git a/server/resource_controller.go b/server/resource_controller.go
index be0edb80..1a236913 100644
--- a/server/resource_controller.go
+++ b/server/resource_controller.go
@@ -291,9 +291,6 @@ func (u CustomJSONRenderer) Render(w http.ResponseWriter) (err error) {
 	data = bytes.Replace(data, []byte("\\u003e"), []byte(">"), -1)
 	data = bytes.Replace(data, []byte("\\u0026"), []byte("&"), -1)
 
-	// Convert "_id" to "id"
-	data = bytes.Replace(data, []byte("\"_id\":"), []byte("\"id\":"), -1)
-
 	writeContentType(w, fhirJSONContentType)
 	_, err = w.Write(data)
 	return