diff --git a/icu4c/source/common/unicode/edits.h b/icu4c/source/common/unicode/edits.h
index 244347f2e6e..f69cd8db366 100644
--- a/icu4c/source/common/unicode/edits.h
+++ b/icu4c/source/common/unicode/edits.h
@@ -378,7 +378,10 @@ public:
          *         not counting unchanged spans
          * @stable ICU 59
          */
-        int32_t replacementIndex() const { return replIndex; }
+        int32_t replacementIndex() const {
+            // TODO: Throw an exception if we aren't in a change edit?
+            return replIndex;
+        }
 
         /**
          * The start index of the current span in the destination string; the span has length
diff --git a/icu4j/main/classes/core/src/com/ibm/icu/text/Edits.java b/icu4j/main/classes/core/src/com/ibm/icu/text/Edits.java
index 4c1d98897bc..d8394321e57 100644
--- a/icu4j/main/classes/core/src/com/ibm/icu/text/Edits.java
+++ b/icu4j/main/classes/core/src/com/ibm/icu/text/Edits.java
@@ -805,7 +805,10 @@ public final class Edits {
          *         spans
          * @stable ICU 59
          */
-        public int replacementIndex() { return replIndex; }
+        public int replacementIndex() {
+            // TODO: Throw an exception if we aren't in a change edit?
+            return replIndex;
+        }
 
         /**
          * The start index of the current span in the destination string; the span has length