diff --git a/google-cloud-storage/src/main/java/com/google/cloud/storage/transfermanager/DownloadResult.java b/google-cloud-storage/src/main/java/com/google/cloud/storage/transfermanager/DownloadResult.java
index aba05b5d46..27e4c9529b 100644
--- a/google-cloud-storage/src/main/java/com/google/cloud/storage/transfermanager/DownloadResult.java
+++ b/google-cloud-storage/src/main/java/com/google/cloud/storage/transfermanager/DownloadResult.java
@@ -138,8 +138,12 @@ public Builder setException(@NonNull StorageException exception) {
     public DownloadResult build() {
       checkNotNull(input);
       checkNotNull(status);
-      // TODO: validate either outputDestination or exception are non-null relative to the value of
-      // status.
+      if (status == TransferStatus.SUCCESS) {
+        checkNotNull(outputDestination);
+      } else if (status == TransferStatus.FAILED_TO_START
+          || status == TransferStatus.FAILED_TO_FINISH) {
+        checkNotNull(exception);
+      }
       return new DownloadResult(input, outputDestination, status, exception);
     }
   }
diff --git a/google-cloud-storage/src/main/java/com/google/cloud/storage/transfermanager/UploadResult.java b/google-cloud-storage/src/main/java/com/google/cloud/storage/transfermanager/UploadResult.java
index b67d7fcd5d..2f8b918694 100644
--- a/google-cloud-storage/src/main/java/com/google/cloud/storage/transfermanager/UploadResult.java
+++ b/google-cloud-storage/src/main/java/com/google/cloud/storage/transfermanager/UploadResult.java
@@ -137,8 +137,12 @@ public Builder setException(@NonNull StorageException exception) {
     public UploadResult build() {
       checkNotNull(input);
       checkNotNull(status);
-      // TODO: validate either uploadedBlob or exception are non-null relative to the value of
-      // status.
+      if (status == TransferStatus.SUCCESS) {
+        checkNotNull(uploadedBlob);
+      } else if (status == TransferStatus.FAILED_TO_START
+          || status == TransferStatus.FAILED_TO_FINISH) {
+        checkNotNull(exception);
+      }
       return new UploadResult(input, status, uploadedBlob, exception);
     }
   }