diff --git a/icu4j/main/classes/core/src/com/ibm/icu/text/DecimalFormat.java b/icu4j/main/classes/core/src/com/ibm/icu/text/DecimalFormat.java
index 6a2cf62017e..6e6b889c29d 100644
--- a/icu4j/main/classes/core/src/com/ibm/icu/text/DecimalFormat.java
+++ b/icu4j/main/classes/core/src/com/ibm/icu/text/DecimalFormat.java
@@ -1718,12 +1718,12 @@ public class DecimalFormat extends NumberFormat {
                 }
                 result.append(decimal);
                 // [Spark/CDL] Add attribute for decimal separator
+                fracBegin = result.length();
                 if (parseAttr) {
                     // Length of decimal separator is 1.
                     int decimalSeparatorBegin = result.length() - 1;
                     addAttribute(Field.DECIMAL_SEPARATOR, decimalSeparatorBegin,
                                  result.length());
-                    fracBegin = result.length();
                 }
                 // Record field information for caller.
                 if (fieldPosition.getField() == NumberFormat.FRACTION_FIELD) {
@@ -1748,6 +1748,11 @@ public class DecimalFormat extends NumberFormat {
             result.append(digits[0]);
         }
 
+        // http://bugs.icu-project.org/trac/ticket/11621
+        if ((fracBegin == -1) && this.decimalSeparatorAlwaysShown) {
+            result.append(decimal);
+        }
+        
         // Record field information
         if (fieldPosition.getField() == NumberFormat.INTEGER_FIELD) {
             if (fieldPosition.getEndIndex() < 0) {
diff --git a/icu4j/main/tests/core/src/com/ibm/icu/dev/test/format/NumberFormatTest.java b/icu4j/main/tests/core/src/com/ibm/icu/dev/test/format/NumberFormatTest.java
index 43ffaf282a1..c43989292bf 100644
--- a/icu4j/main/tests/core/src/com/ibm/icu/dev/test/format/NumberFormatTest.java
+++ b/icu4j/main/tests/core/src/com/ibm/icu/dev/test/format/NumberFormatTest.java
@@ -555,7 +555,7 @@ public class NumberFormatTest extends com.ibm.icu.dev.test.TestFmwk {
             }
         }
     }
-    
+   
     public void Test10419RoundingWith0FractionDigits() {
         Object[][] data = new Object[][]{
                 {BigDecimal.ROUND_CEILING, 1.488, "2"},
@@ -4527,4 +4527,20 @@ public class NumberFormatTest extends com.ibm.icu.dev.test.TestFmwk {
         assertEquals("End index:  ", 11, iterator.getEndIndex());
     }
 
+    // Test that the decimal is shown even when there are no fractional digits
+    public void Test11621() throws Exception {
+        String pat = "0.##E0";
+
+        DecimalFormatSymbols icuSym = new DecimalFormatSymbols(Locale.US);
+        DecimalFormat icuFmt = new DecimalFormat(pat, icuSym);
+        icuFmt.setDecimalSeparatorAlwaysShown(true);
+        String icu = ((NumberFormat)icuFmt).format(299792458);
+
+        java.text.DecimalFormatSymbols jdkSym = new java.text.DecimalFormatSymbols(Locale.US);
+        java.text.DecimalFormat jdkFmt = new java.text.DecimalFormat(pat,jdkSym);
+        jdkFmt.setDecimalSeparatorAlwaysShown(true);
+        String jdk = ((java.text.NumberFormat)jdkFmt).format(299792458);
+
+        assertEquals("ICU and JDK placement of decimal in exponent", jdk, icu);
+    }
 }