diff --git a/hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/dao/data/IMdmLinkDao.java b/hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/dao/data/IMdmLinkDao.java
index 16834facbe2..be0a6289a4e 100644
--- a/hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/dao/data/IMdmLinkDao.java
+++ b/hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/dao/data/IMdmLinkDao.java
@@ -67,4 +67,13 @@ public interface IMdmLinkDao extends JpaRepository<MdmLink, Long> {
 		"AND ml.myMatchResult=:matchResult")
 	List<MdmPidTuple> expandPidsBySourcePidAndMatchResult(@Param("sourcePid") Long theSourcePid, @Param("matchResult") MdmMatchResultEnum theMdmMatchResultEnum);
 
+	@Query("SELECT DISTINCT ml.myGoldenResourcePid as goldenPid, ml.mySourcePid as sourcePid " +
+		"FROM MdmLink ml " +
+		"INNER JOIN MdmLink ml2 " +
+		"ON ml.myGoldenResourcePid = ml2.myGoldenResourcePid " +
+		"WHERE (ml2.mySourcePid = :sourceOrGoldenPid OR ml2.myGoldenResourcePid = :sourceOrGoldenPid) " +
+		"AND ml2.myMatchResult=:matchResult " +
+		"AND ml.myMatchResult=:matchResult")
+	List<MdmPidTuple> expandPidsBySourceOrGoldenResourcePidAndMatchResult(@Param("sourceOrGoldenPid") Long theSourceOrGoldenPid, @Param("matchResult") MdmMatchResultEnum theMdmMatchResultEnum);
+
 }
diff --git a/hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/dao/mdm/MdmLinkExpandSvc.java b/hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/dao/mdm/MdmLinkExpandSvc.java
index 66af7f5a706..b03e22d04b8 100644
--- a/hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/dao/mdm/MdmLinkExpandSvc.java
+++ b/hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/dao/mdm/MdmLinkExpandSvc.java
@@ -72,6 +72,19 @@ public class MdmLinkExpandSvc {
 		return expandMdmBySourceResourcePid(pidOrThrowException);
 	}
 
+	/**
+	 *  Given a resource ID of a source resource or golden resource, perform MDM expansion and return all the resource
+	 *  IDs of all resources that are MDM-Matched to this resource.
+	 *
+	 * @param theId The Resource ID of the resource to MDM-Expand
+	 * @return A set of strings representing the FHIR ids of the expanded resources.
+	 */
+	public Set<String> expandMdmBySourceOrGoldenResourceId(IIdType theId) {
+		ourLog.debug("About to expand source resource with resource id {}", theId);
+		Long pidOrThrowException = myIdHelperService.getPidOrThrowException(theId);
+		return flatten(myMdmLinkDao.expandPidsBySourceOrGoldenResourcePidAndMatchResult(pidOrThrowException, MdmMatchResultEnum.MATCH));
+	}
+
 	/**
 	 *  Given a PID of a source resource, perform MDM expansion and return all the resource IDs of all resources that are
 	 *  MDM-Matched to this resource.
@@ -81,14 +94,17 @@ public class MdmLinkExpandSvc {
 	 */
 	public Set<String> expandMdmBySourceResourcePid(Long theSourceResourcePid) {
 		ourLog.debug("About to expand source resource with PID {}", theSourceResourcePid);
-		List<IMdmLinkDao.MdmPidTuple> goldenPidSourcePidTuples = myMdmLinkDao.expandPidsBySourcePidAndMatchResult(theSourceResourcePid, MdmMatchResultEnum.MATCH);
+		return flatten(myMdmLinkDao.expandPidsBySourcePidAndMatchResult(theSourceResourcePid, MdmMatchResultEnum.MATCH));
+	}
+
+	protected Set<String> flatten(List<IMdmLinkDao.MdmPidTuple> thePidTuples) {
 		Set<Long> flattenedPids = new HashSet<>();
-		goldenPidSourcePidTuples.forEach(tuple -> {
+		thePidTuples.forEach(tuple -> {
 			flattenedPids.add(tuple.getSourcePid());
 			flattenedPids.add(tuple.getGoldenPid());
 		});
 		Set<String> resourceIds = myIdHelperService.translatePidsToFhirResourceIds(flattenedPids);
-		ourLog.debug("Pid {} has been expanded to [{}]", theSourceResourcePid, String.join(",", resourceIds));
+		ourLog.debug("Expanded pids are [{}]", String.join(",", resourceIds));
 		return resourceIds;
 	}
 
diff --git a/hapi-fhir-jpaserver-mdm/src/test/java/ca/uhn/fhir/jpa/mdm/dao/MdmLinkDaoSvcTest.java b/hapi-fhir-jpaserver-mdm/src/test/java/ca/uhn/fhir/jpa/mdm/dao/MdmLinkDaoSvcTest.java
index ae034af6fa7..b5deb25f0c6 100644
--- a/hapi-fhir-jpaserver-mdm/src/test/java/ca/uhn/fhir/jpa/mdm/dao/MdmLinkDaoSvcTest.java
+++ b/hapi-fhir-jpaserver-mdm/src/test/java/ca/uhn/fhir/jpa/mdm/dao/MdmLinkDaoSvcTest.java
@@ -83,6 +83,15 @@ public class MdmLinkDaoSvcTest extends BaseMdmR4Test {
 
 		assertThat(lists, hasSize(10));
 
+		lists.stream()
+			.forEach(tuple -> {
+					assertThat(tuple.getGoldenPid(), is(equalTo(golden.getIdElement().getIdPartAsLong())));
+					assertThat(tuple.getSourcePid(), is(in(expectedExpandedPids)));
+				});
+
+		lists = myMdmLinkDao.expandPidsBySourceOrGoldenResourcePidAndMatchResult(mdmLinks.get(0).getGoldenResourcePid(), MdmMatchResultEnum.MATCH);
+		assertThat(lists, hasSize(10));
+
 		lists.stream()
 			.forEach(tuple -> {
 					assertThat(tuple.getGoldenPid(), is(equalTo(golden.getIdElement().getIdPartAsLong())));
diff --git a/hapi-fhir-server-mdm/src/main/java/ca/uhn/fhir/mdm/api/MdmLinkChangeEvent.java b/hapi-fhir-server-mdm/src/main/java/ca/uhn/fhir/mdm/api/MdmLinkChangeEvent.java
index e2d6b199812..8e306c16e6e 100644
--- a/hapi-fhir-server-mdm/src/main/java/ca/uhn/fhir/mdm/api/MdmLinkChangeEvent.java
+++ b/hapi-fhir-server-mdm/src/main/java/ca/uhn/fhir/mdm/api/MdmLinkChangeEvent.java
@@ -30,9 +30,21 @@ import java.util.Set;
 
 public class MdmLinkChangeEvent implements IModelJson {
 
-	@JsonProperty(value = "targetResourceId")
+	@JsonProperty(value = "matchResult")
+	private MdmMatchResultEnum myMdmMatchResult;
+	@JsonProperty(value = "linkSource")
+	private MdmLinkSourceEnum myMdmLinkSource;
+	@JsonProperty(value = "eidMatch")
+	private Boolean myEidMatch;
+	@JsonProperty(value = "newGoldenResource")
+	private Boolean myNewGoldenResource;
+	@JsonProperty(value = "score")
+	private Double myScore;
+	@JsonProperty(value = "ruleCount")
+	private Long myRuleCount;
+	@JsonProperty(value = "targetResourceId", required = true)
 	private String myTargetResourceId;
-	@JsonProperty(value = "goldenResourceId")
+	@JsonProperty(value = "goldenResourceId", required = true)
 	private String myGoldenResourceId;
 	@JsonProperty(value = "duplicateResourceIds")
 	private Set<String> myDuplicateGoldenResourceIds = new HashSet<>();
@@ -88,10 +100,64 @@ public class MdmLinkChangeEvent implements IModelJson {
 		return this;
 	}
 
+	public MdmMatchResultEnum getMdmMatchResult() {
+		return myMdmMatchResult;
+	}
+
+	public void setMdmMatchResult(MdmMatchResultEnum theMdmMatchResult) {
+		myMdmMatchResult = theMdmMatchResult;
+	}
+
+	public MdmLinkSourceEnum getMdmLinkSource() {
+		return myMdmLinkSource;
+	}
+
+	public void setMdmLinkSource(MdmLinkSourceEnum theMdmLinkSource) {
+		myMdmLinkSource = theMdmLinkSource;
+	}
+
+	public Boolean getEidMatch() {
+		return myEidMatch;
+	}
+
+	public void setEidMatch(Boolean theEidMatch) {
+		myEidMatch = theEidMatch;
+	}
+
+	public Boolean getNewGoldenResource() {
+		return myNewGoldenResource;
+	}
+
+	public void setNewGoldenResource(Boolean theNewGoldenResource) {
+		myNewGoldenResource = theNewGoldenResource;
+	}
+
+	public Double getScore() {
+		return myScore;
+	}
+
+	public void setScore(Double theScore) {
+		myScore = theScore;
+	}
+
+	public Long getRuleCount() {
+		return myRuleCount;
+	}
+
+	public void setRuleCount(Long theRuleCount) {
+		myRuleCount = theRuleCount;
+	}
+
 	@Override
 	public String toString() {
 		return "MdmLinkChangeEvent{" +
-			"myTargetResourceId='" + myTargetResourceId + '\'' +
+			"myMdmMatchResult=" + myMdmMatchResult +
+			", myMdmLinkSource=" + myMdmLinkSource +
+			", myEidMatch=" + myEidMatch +
+			", myNewGoldenResource=" + myNewGoldenResource +
+			", myScore=" + myScore +
+			", myRuleCount=" + myRuleCount +
+			", myTargetResourceId='" + myTargetResourceId + '\'' +
 			", myGoldenResourceId='" + myGoldenResourceId + '\'' +
 			", myDuplicateGoldenResourceIds=" + myDuplicateGoldenResourceIds +
 			'}';