diff --git a/src/Db/Adapter/PostgresAdapter.php b/src/Db/Adapter/PostgresAdapter.php
index f2f19dc7..0ac51fdf 100644
--- a/src/Db/Adapter/PostgresAdapter.php
+++ b/src/Db/Adapter/PostgresAdapter.php
@@ -1286,13 +1286,17 @@ protected function getIndexSqlDefinition(Index $index, string $tableName): strin
         }, $columnNames);
 
         $include = $index->getInclude();
-        $includedColumns = $include ? sprintf('INCLUDE ("%s")', implode('","', $include)) : '';
+        $includedColumns = $include ? sprintf(' INCLUDE ("%s")', implode('","', $include)) : '';
 
         $createIndexSentence = 'CREATE %sINDEX%s %s ON %s ';
         if ($index->getType() === self::GIN_INDEX_TYPE) {
             $createIndexSentence .= ' USING ' . $index->getType() . '(%s) %s;';
         } else {
-            $createIndexSentence .= '(%s) %s;';
+            $createIndexSentence .= '(%s)%s%s;';
+        }
+        $where = (string)$index->getWhere();
+        if ($where) {
+            $where = ' WHERE ' . $where;
         }
 
         return sprintf(
@@ -1302,7 +1306,8 @@ protected function getIndexSqlDefinition(Index $index, string $tableName): strin
             $this->quoteColumnName((string)$indexName),
             $this->quoteTableName($tableName),
             implode(',', $columnNames),
-            $includedColumns
+            $includedColumns,
+            $where,
         );
     }
 
diff --git a/src/Db/Adapter/SqliteAdapter.php b/src/Db/Adapter/SqliteAdapter.php
index 09fa5c24..90db97a1 100644
--- a/src/Db/Adapter/SqliteAdapter.php
+++ b/src/Db/Adapter/SqliteAdapter.php
@@ -1378,11 +1378,16 @@ protected function getAddIndexInstructions(Table $table, Index $index): AlterIns
             $indexColumnArray[] = sprintf('`%s` ASC', $column);
         }
         $indexColumns = implode(',', $indexColumnArray);
+        $where = (string)$index->getWhere();
+        if ($where) {
+            $where = ' WHERE ' . $where;
+        }
         $sql = sprintf(
-            'CREATE %s ON %s (%s)',
+            'CREATE %s ON %s (%s)%s',
             $this->getIndexSqlDefinition($table, $index),
             $this->quoteTableName($table->getName()),
-            $indexColumns
+            $indexColumns,
+            $where
         );
 
         return new AlterInstructions([], [$sql]);
diff --git a/src/Db/Adapter/SqlserverAdapter.php b/src/Db/Adapter/SqlserverAdapter.php
index 77a77945..f6b990ce 100644
--- a/src/Db/Adapter/SqlserverAdapter.php
+++ b/src/Db/Adapter/SqlserverAdapter.php
@@ -1200,14 +1200,19 @@ protected function getIndexSqlDefinition(Index $index, string $tableName): strin
 
         $include = $index->getInclude();
         $includedColumns = $include ? sprintf('INCLUDE ([%s])', implode('],[', $include)) : '';
+        $where = (string)$index->getWhere();
+        if ($where) {
+            $where = ' WHERE ' . $where;
+        }
 
         return sprintf(
-            'CREATE %s INDEX %s ON %s (%s) %s;',
+            'CREATE %s INDEX %s ON %s (%s) %s%s;',
             ($index->getType() === Index::UNIQUE ? 'UNIQUE' : ''),
             $indexName,
             $this->quoteTableName($tableName),
             implode(',', $columnNames),
-            $includedColumns
+            $includedColumns,
+            $where
         );
     }
 
diff --git a/src/Db/Table/Index.php b/src/Db/Table/Index.php
index a044e803..89cac034 100644
--- a/src/Db/Table/Index.php
+++ b/src/Db/Table/Index.php
@@ -17,10 +17,6 @@
  *
  * @see \Migrations\BaseMigration::index()
  * @see \Migrations\Db\Table::addIndex()
- *
- * TODO expand functionality of Index:
- * - Add ifnotexists
- * - Add where for partial indexes
  */
 class Index
 {
@@ -74,6 +70,11 @@ class Index
      */
     protected bool $concurrent = false;
 
+    /**
+     * @var string|null The where clause for partial indexes.
+     */
+    protected ?string $where = null;
+
     /**
      * Sets the index columns.
      *
@@ -245,6 +246,29 @@ public function getConcurrently(): bool
         return $this->concurrent;
     }
 
+    /**
+     * Set the where clause for partial indexes.
+     *
+     * @param ?string $where The where clause for partial indexes.
+     * @return $this
+     */
+    public function setWhere(?string $where)
+    {
+        $this->where = $where;
+
+        return $this;
+    }
+
+    /**
+     * Get the where clause for partial indexes.
+     *
+     * @return ?string
+     */
+    public function getWhere(): ?string
+    {
+        return $this->where;
+    }
+
     /**
      * Utility method that maps an array of index options to this objects methods.
      *
@@ -255,7 +279,7 @@ public function getConcurrently(): bool
     public function setOptions(array $options)
     {
         // Valid Options
-        $validOptions = ['type', 'unique', 'name', 'limit', 'order', 'include'];
+        $validOptions = ['concurrently', 'type', 'unique', 'name', 'limit', 'order', 'include', 'where'];
         foreach ($options as $option => $value) {
             if (!in_array($option, $validOptions, true)) {
                 throw new RuntimeException(sprintf('"%s" is not a valid index option.', $option));
diff --git a/tests/TestCase/Db/Adapter/PostgresAdapterTest.php b/tests/TestCase/Db/Adapter/PostgresAdapterTest.php
index 7892912e..8eec4664 100644
--- a/tests/TestCase/Db/Adapter/PostgresAdapterTest.php
+++ b/tests/TestCase/Db/Adapter/PostgresAdapterTest.php
@@ -429,6 +429,28 @@ public function testCreateTableWithIndexConcurrently(): void
         $this->assertStringContainsString('CREATE UNIQUE INDEX CONCURRENTLY "table1_email"', $indexQuery);
     }
 
+    public function testCreateTableIndexWithWhere(): void
+    {
+        $options = $this->adapter->getOptions();
+        $options['dryrun'] = true;
+        $this->adapter->setOptions($options);
+
+        $index = new Index();
+        $index->setColumns('email')
+            ->setType(Index::UNIQUE)
+            ->setWhere('is_verified = true');
+
+        $table = new Table('table1', [], $this->adapter);
+        $table->addColumn('email', 'string')
+              ->addColumn('is_verified', 'boolean')
+              ->addIndex($index)
+              ->save();
+        $queries = $this->out->messages();
+        $indexQuery = $queries[3];
+        $this->assertStringContainsString('CREATE UNIQUE INDEX "table1_email"', $indexQuery);
+        $this->assertStringContainsString('("email") WHERE is_verified = true', $indexQuery);
+    }
+
     public function testAddPrimaryKey()
     {
         $table = new Table('table1', ['id' => false], $this->adapter);
diff --git a/tests/TestCase/Db/Adapter/SqliteAdapterTest.php b/tests/TestCase/Db/Adapter/SqliteAdapterTest.php
index f1212768..d6f04e68 100644
--- a/tests/TestCase/Db/Adapter/SqliteAdapterTest.php
+++ b/tests/TestCase/Db/Adapter/SqliteAdapterTest.php
@@ -18,6 +18,7 @@
 use Migrations\Db\Table;
 use Migrations\Db\Table\Column;
 use Migrations\Db\Table\ForeignKey;
+use Migrations\Db\Table\Index;
 use PDOException;
 use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\TestCase;
@@ -358,6 +359,28 @@ public function testCreateTableWithoutAutoIncrementingPrimaryKeyAndWithForeignKe
         );
     }
 
+    public function testCreateTableIndexWithWhere(): void
+    {
+        $options = $this->adapter->getOptions();
+        $options['dryrun'] = true;
+        $this->adapter->setOptions($options);
+
+        $index = new Index();
+        $index->setColumns('email')
+            ->setType(Index::UNIQUE)
+            ->setWhere('is_verified = true');
+
+        $table = new Table('table1', [], $this->adapter);
+        $table->addColumn('email', 'string')
+              ->addColumn('is_verified', 'boolean')
+              ->addIndex($index)
+              ->save();
+        $queries = $this->out->messages();
+        $indexQuery = $queries[2];
+        $this->assertStringContainsString('CREATE UNIQUE INDEX `table1_email_index`', $indexQuery);
+        $this->assertStringContainsString('(`email` ASC) WHERE is_verified = true', $indexQuery);
+    }
+
     public function testAddPrimaryKey()
     {
         $table = new Table('table1', ['id' => false], $this->adapter);
diff --git a/tests/TestCase/Db/Adapter/SqlserverAdapterTest.php b/tests/TestCase/Db/Adapter/SqlserverAdapterTest.php
index 5b9bfa8f..ff04773f 100644
--- a/tests/TestCase/Db/Adapter/SqlserverAdapterTest.php
+++ b/tests/TestCase/Db/Adapter/SqlserverAdapterTest.php
@@ -15,6 +15,7 @@
 use Migrations\Db\Table;
 use Migrations\Db\Table\Column;
 use Migrations\Db\Table\ForeignKey;
+use Migrations\Db\Table\Index;
 use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\Attributes\Depends;
 use PHPUnit\Framework\TestCase;
@@ -305,6 +306,29 @@ public function testCreateTableWithNamedIndexes()
         $this->assertTrue($this->adapter->hasIndexByName('table1', 'myemailindex'));
     }
 
+    public function testCreateTableIndexWithWhere(): void
+    {
+        $options = $this->adapter->getOptions();
+        $options['dryrun'] = true;
+        $this->adapter->setOptions($options);
+
+        $index = new Index();
+        $index->setColumns('email')
+            ->setName('active_email_index')
+            ->setType(Index::UNIQUE)
+            ->setWhere('is_verified = true');
+
+        $table = new Table('table1', [], $this->adapter);
+        $table->addColumn('email', 'string')
+              ->addColumn('is_verified', 'boolean')
+              ->addIndex($index)
+              ->save();
+        $queries = $this->out->messages();
+        $indexQuery = $queries[2];
+        $this->assertStringContainsString('CREATE UNIQUE INDEX [active_email_index]', $indexQuery);
+        $this->assertStringContainsString('([email]) WHERE is_verified = true', $indexQuery);
+    }
+
     public function testAddPrimaryKey()
     {
         $table = new Table('table1', ['id' => false], $this->adapter);