diff --git a/icu4j/main/classes/core/src/com/ibm/icu/util/JapaneseCalendar.java b/icu4j/main/classes/core/src/com/ibm/icu/util/JapaneseCalendar.java
index 99f1e7b2a1d..11a4a86907a 100644
--- a/icu4j/main/classes/core/src/com/ibm/icu/util/JapaneseCalendar.java
+++ b/icu4j/main/classes/core/src/com/ibm/icu/util/JapaneseCalendar.java
@@ -386,6 +386,12 @@ public class JapaneseCalendar extends GregorianCalendar {
      */
     static public final int HEISEI;
 
+    /**
+     * Constant for the era starting on May 1, 2019 AD.
+     * @stable ICU 64
+     */
+    static public final int REIWA;
+
     // We want to make these era constants initialized in a static initializer
     // block to prevent javac to inline these values in a consumer code.
     // By doing so, we can keep better binary compatibility across versions even
@@ -395,6 +401,7 @@ public class JapaneseCalendar extends GregorianCalendar {
         TAISHO = 233;
         SHOWA = 234;
         HEISEI = 235;
+        REIWA = 236;
         CURRENT_ERA = ERA_RULES.getCurrentEraIndex();
     }