diff --git a/maven-api-impl/src/main/java/org/apache/maven/internal/impl/model/BuildModelTransformer.java b/maven-api-impl/src/main/java/org/apache/maven/internal/impl/model/BuildModelTransformer.java
index d8c622380d..69f70c222f 100644
--- a/maven-api-impl/src/main/java/org/apache/maven/internal/impl/model/BuildModelTransformer.java
+++ b/maven-api-impl/src/main/java/org/apache/maven/internal/impl/model/BuildModelTransformer.java
@@ -20,7 +20,6 @@ package org.apache.maven.internal.impl.model;
 
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -58,34 +57,13 @@ public class BuildModelTransformer implements ModelTransformer {
     void handleParent(ModelTransformerContext context, Model model, Path pomFile, Model.Builder builder) {
         Parent parent = model.getParent();
         if (parent != null) {
-            String groupId = parent.getGroupId();
-            String artifactId = parent.getArtifactId();
             String version = parent.getVersion();
-            String path = Optional.ofNullable(parent.getRelativePath()).orElse("..");
-            if (version == null && !path.isEmpty()) {
-                Optional<RelativeProject> resolvedParent = resolveRelativePath(
-                        pomFile, context, Paths.get(path), parent.getGroupId(), parent.getArtifactId());
-                if (resolvedParent.isPresent()) {
-                    RelativeProject project = resolvedParent.get();
-                    if (groupId == null
-                            || groupId.equals(project.getGroupId()) && artifactId == null
-                            || artifactId.equals(project.getArtifactId())) {
-                        groupId = project.getGroupId();
-                        artifactId = project.getArtifactId();
-                        version = resolvedParent.get().getVersion();
-                    }
-                }
-            }
 
             // CI Friendly version for parent
             String modVersion = replaceCiFriendlyVersion(context, version);
 
             // Update parent
-            builder.parent(parent.with()
-                    .groupId(groupId)
-                    .artifactId(artifactId)
-                    .version(modVersion)
-                    .build());
+            builder.parent(parent.with().version(modVersion).build());
         }
     }
 
diff --git a/maven-api-impl/src/main/java/org/apache/maven/internal/impl/model/DefaultModelBuilder.java b/maven-api-impl/src/main/java/org/apache/maven/internal/impl/model/DefaultModelBuilder.java
index f3a9822b82..d341c75523 100644
--- a/maven-api-impl/src/main/java/org/apache/maven/internal/impl/model/DefaultModelBuilder.java
+++ b/maven-api-impl/src/main/java/org/apache/maven/internal/impl/model/DefaultModelBuilder.java
@@ -23,6 +23,7 @@ import java.io.InputStream;
 import java.lang.reflect.Field;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
@@ -31,6 +32,7 @@ import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.Properties;
 import java.util.concurrent.Callable;
 import java.util.concurrent.atomic.AtomicReference;
@@ -740,6 +742,40 @@ public class DefaultModelBuilder implements ModelBuilder {
         if (modelSource.getPath() != null) {
             model = model.withPomFile(modelSource.getPath());
 
+            Parent parent = model.getParent();
+            if (parent != null) {
+                String groupId = parent.getGroupId();
+                String artifactId = parent.getArtifactId();
+                String version = parent.getVersion();
+                String path = Optional.ofNullable(parent.getRelativePath()).orElse("..");
+                if (version == null && !path.isEmpty()) {
+                    Path pomFile = model.getPomFile();
+                    Path relativePath = Paths.get(path);
+                    Path pomPath = pomFile.resolveSibling(relativePath).normalize();
+                    if (Files.isDirectory(pomPath)) {
+                        pomPath = getModelProcessor().locateExistingPom(pomPath);
+                    }
+                    if (pomPath != null && Files.isRegularFile(pomPath)) {
+                        ModelBuilderRequest parentRequest =
+                                ModelBuilderRequest.build(request, ModelSource.fromPath(pomPath));
+                        Model parentModel = readFileModel(parentRequest, problems);
+                        if (parentModel != null) {
+                            String parentGroupId = getGroupId(parentModel);
+                            String parentArtifactId = parentModel.getArtifactId();
+                            String parentVersion = getVersion(parentModel);
+                            if ((groupId == null || groupId.equals(parentGroupId))
+                                    && (artifactId == null || artifactId.equals(parentArtifactId))) {
+                                model = model.withParent(parent.with()
+                                        .groupId(parentGroupId)
+                                        .artifactId(parentArtifactId)
+                                        .version(parentVersion)
+                                        .build());
+                            }
+                        }
+                    }
+                }
+            }
+
             // subprojects discovery
             if (model.getSubprojects().isEmpty()
                     && model.getModules().isEmpty()
diff --git a/maven-api-impl/src/main/java/org/apache/maven/internal/impl/model/MavenModelMerger.java b/maven-api-impl/src/main/java/org/apache/maven/internal/impl/model/MavenModelMerger.java
index 844b35188f..d340b280e0 100644
--- a/maven-api-impl/src/main/java/org/apache/maven/internal/impl/model/MavenModelMerger.java
+++ b/maven-api-impl/src/main/java/org/apache/maven/internal/impl/model/MavenModelMerger.java
@@ -231,6 +231,37 @@ public class MavenModelMerger extends MavenMerger {
         }
     }
 
+    @Override
+    protected void mergeModelBase_Subprojects(
+            ModelBase.Builder builder,
+            ModelBase target,
+            ModelBase source,
+            boolean sourceDominant,
+            Map<Object, Object> context) {
+        List<String> src = source.getSubprojects();
+        if (!src.isEmpty() && sourceDominant) {
+            List<Integer> indices = new ArrayList<>();
+            List<String> tgt = target.getSubprojects();
+            Set<String> excludes = new LinkedHashSet<>(tgt);
+            List<String> merged = new ArrayList<>(tgt.size() + src.size());
+            merged.addAll(tgt);
+            for (int i = 0, n = tgt.size(); i < n; i++) {
+                indices.add(i);
+            }
+            for (int i = 0, n = src.size(); i < n; i++) {
+                String s = src.get(i);
+                if (!excludes.contains(s)) {
+                    merged.add(s);
+                    indices.add(~i);
+                }
+            }
+            builder.subprojects(merged);
+            builder.location(
+                    "subprojects",
+                    InputLocation.merge(target.getLocation("subprojects"), source.getLocation("subprojects"), indices));
+        }
+    }
+
     /*
      * TODO: The order of the merged list could be controlled by an attribute in the model association: target-first,
      * source-first, dominant-first, recessive-first