diff --git a/java/vector/src/main/codegen/templates/UnionVector.java b/java/vector/src/main/codegen/templates/UnionVector.java
index ea79c5c2fba76..7724750a83d69 100644
--- a/java/vector/src/main/codegen/templates/UnionVector.java
+++ b/java/vector/src/main/codegen/templates/UnionVector.java
@@ -23,6 +23,7 @@
 import org.apache.arrow.util.Preconditions;
 import org.apache.arrow.vector.BaseValueVector;
 import org.apache.arrow.vector.BitVectorHelper;
+import org.apache.arrow.vector.DecimalVector;
 import org.apache.arrow.vector.FieldVector;
 import org.apache.arrow.vector.ValueVector;
 import org.apache.arrow.vector.complex.AbstractStructVector;
@@ -278,7 +279,10 @@ public StructVector getStruct() {
   <#if minor.class?starts_with("Decimal") || is_timestamp_tz(minor.class) || minor.class == "Duration" || minor.class == "FixedSizeBinary">
   public ${name}Vector get${name}Vector() {
     if (${uncappedName}Vector == null) {
-      throw new IllegalArgumentException("No ${name} present. Provide ArrowType argument to create a new vector");
+      ${uncappedName}Vector = internalStruct.getChild(fieldName(MinorType.${name?upper_case}), ${name}Vector.class);
+      if (${uncappedName}Vector == null) {
+        throw new IllegalArgumentException("No ${name} present. Provide ArrowType argument to create a new vector");
+      }
     }
     return ${uncappedName}Vector;
   }
diff --git a/java/vector/src/test/java/org/apache/arrow/vector/complex/impl/TestPromotableWriter.java b/java/vector/src/test/java/org/apache/arrow/vector/complex/impl/TestPromotableWriter.java
index 1068f7c030eb5..a68fde2b1ad4b 100644
--- a/java/vector/src/test/java/org/apache/arrow/vector/complex/impl/TestPromotableWriter.java
+++ b/java/vector/src/test/java/org/apache/arrow/vector/complex/impl/TestPromotableWriter.java
@@ -22,11 +22,13 @@
 import static org.junit.Assert.assertNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
+import java.math.BigDecimal;
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 
 import org.apache.arrow.memory.ArrowBuf;
 import org.apache.arrow.memory.BufferAllocator;
+import org.apache.arrow.vector.DecimalVector;
 import org.apache.arrow.vector.DirtyRootAllocator;
 import org.apache.arrow.vector.complex.ListVector;
 import org.apache.arrow.vector.complex.NonNullableStructVector;
@@ -35,14 +37,18 @@
 import org.apache.arrow.vector.complex.writer.BaseWriter.StructWriter;
 import org.apache.arrow.vector.holders.DurationHolder;
 import org.apache.arrow.vector.holders.FixedSizeBinaryHolder;
+import org.apache.arrow.vector.holders.NullableDecimalHolder;
+import org.apache.arrow.vector.holders.NullableIntHolder;
 import org.apache.arrow.vector.holders.NullableTimeStampMilliTZHolder;
 import org.apache.arrow.vector.holders.TimeStampMilliTZHolder;
+import org.apache.arrow.vector.holders.UnionHolder;
 import org.apache.arrow.vector.types.TimeUnit;
 import org.apache.arrow.vector.types.Types;
 import org.apache.arrow.vector.types.pojo.ArrowType;
 import org.apache.arrow.vector.types.pojo.ArrowType.ArrowTypeID;
 import org.apache.arrow.vector.types.pojo.Field;
 import org.apache.arrow.vector.types.pojo.FieldType;
+import org.apache.arrow.vector.util.DecimalUtility;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -392,4 +398,41 @@ public void testNoPromoteFixedSizeBinaryToUnionWithNull() throws Exception {
       buf.close();
     }
   }
+
+  @Test
+  public void testPromoteToUnionFromDecimal() throws Exception {
+    try (final NonNullableStructVector container = NonNullableStructVector.empty(EMPTY_SCHEMA_PATH, allocator);
+         final DecimalVector v = container.addOrGet("dec",
+             FieldType.nullable(new ArrowType.Decimal(38, 1, 128)), DecimalVector.class);
+         final PromotableWriter writer = new PromotableWriter(v, container)) {
+
+      container.allocateNew();
+      container.setValueCount(1);
+
+      writer.setPosition(0);
+      writer.writeDecimal(new BigDecimal("0.1"));
+      writer.setPosition(1);
+      writer.writeInt(1);
+
+      container.setValueCount(3);
+
+      UnionVector unionVector = (UnionVector) container.getChild("dec");
+      UnionHolder holder = new UnionHolder();
+
+      unionVector.get(0, holder);
+      NullableDecimalHolder decimalHolder = new NullableDecimalHolder();
+      holder.reader.read(decimalHolder);
+
+      assertEquals(1, decimalHolder.isSet);
+      assertEquals(new BigDecimal("0.1"),
+          DecimalUtility.getBigDecimalFromArrowBuf(decimalHolder.buffer, 0, decimalHolder.scale, 128));
+
+      unionVector.get(1, holder);
+      NullableIntHolder intHolder = new NullableIntHolder();
+      holder.reader.read(intHolder);
+
+      assertEquals(1, intHolder.isSet);
+      assertEquals(1, intHolder.value);
+    }
+  }
 }