diff --git a/masque/pattern.py b/masque/pattern.py
index 9cd49c2..e3f8c8c 100644
--- a/masque/pattern.py
+++ b/masque/pattern.py
@@ -486,6 +486,32 @@ class Pattern:
         pat_list = [(p.name if p is not None else None, p) for p in pats_by_id.values()]
         return pat_list
 
+    def subpatterns_by_id(self,
+                          include_none: bool = False,
+                          recursive: bool = True,
+                          ) -> Dict[int, List[subpattern_t]]:
+        """
+        Create a dictionary which maps `{id(referenced_pattern): [subpattern0, ...]}`
+         for all SubPattern objects referenced by this Pattern (by default, operates
+         recursively on all referenced Patterns as well).
+
+        Args:
+            include_none: If `True`, references to `None` will be included. Default `False`.
+            recursive: If `True`, operates recursively on all referenced patterns. Default `True`.
+
+        Returns:
+            Dictionary mapping each pattern id to a list of subpattern objects referencing the pattern.
+        """
+        ids: Dict[int, List[subpattern_t]] = defaultdict(list)
+        for subpat in self.subpatterns:
+            pat = subpat.pattern
+            if include_none or pat is not None:
+                ids[id(pat)].append(subpat)
+            if recursive and pat is not None:
+                ids.update(pat.subpatterns_by_id(include_none=include_none))
+        return dict(ids)
+
+
     def get_bounds(self) -> Union[numpy.ndarray, None]:
         """
         Return a `numpy.ndarray` containing `[[x_min, y_min], [x_max, y_max]]`, corresponding to the