diff --git a/src/Grant/ClientCredentials.php b/src/Grant/ClientCredentials.php
new file mode 100644
index 0000000..7a73a79
--- /dev/null
+++ b/src/Grant/ClientCredentials.php
@@ -0,0 +1,25 @@
+<?php
+
+namespace League\OAuth2\Client\Grant;
+
+use League\OAuth2\Client\Token\AccessToken;
+
+class ClientCredentials implements GrantInterface
+{
+    public function __toString()
+    {
+        return 'client_credentials';
+    }
+
+    public function prepRequestParams($defaultParams, $params)
+    {
+        $params['grant_type'] = 'client_credentials';
+
+        return array_merge($defaultParams, $params);
+    }
+
+    public function handleResponse($response = array())
+    {
+        return new AccessToken($response);
+    }
+}
diff --git a/src/Grant/Password.php b/src/Grant/Password.php
new file mode 100644
index 0000000..b124b34
--- /dev/null
+++ b/src/Grant/Password.php
@@ -0,0 +1,33 @@
+<?php
+
+namespace League\OAuth2\Client\Grant;
+
+use League\OAuth2\Client\Token\AccessToken;
+
+class Password implements GrantInterface
+{
+    public function __toString()
+    {
+        return 'password';
+    }
+
+    public function prepRequestParams($defaultParams, $params)
+    {
+        if (! isset($params['username']) || empty($params['username'])) {
+            throw new \BadMethodCallException('Missing username');
+        }
+
+        if (! isset($params['password']) || empty($params['password'])) {
+            throw new \BadMethodCallException('Missing password');
+        }
+
+        $params['grant_type'] = 'password';
+
+        return array_merge($defaultParams, $params);
+    }
+
+    public function handleResponse($response = array())
+    {
+        return new AccessToken($response);
+    }
+}
diff --git a/test/src/Grant/ClientCredentialsTest.php b/test/src/Grant/ClientCredentialsTest.php
new file mode 100644
index 0000000..39ca9a7
--- /dev/null
+++ b/test/src/Grant/ClientCredentialsTest.php
@@ -0,0 +1,36 @@
+<?php
+
+namespace League\OAuth2\Client\Test\Grant;
+
+use \Mockery as m;
+
+class ClientCredentialsTest extends \PHPUnit_Framework_TestCase
+{
+    protected $provider;
+
+    protected function setUp()
+    {
+        $this->provider = new \League\OAuth2\Client\Provider\Google(array(
+            'clientId' => 'mock_client_id',
+            'clientSecret' => 'mock_secret',
+            'redirectUri' => 'none',
+        ));
+    }
+
+    public function testGetAccessToken()
+    {
+        $response = m::mock('Guzzle\Http\Message\Response');
+        $response->shouldReceive('getBody')->times(2)->andReturn('{"access_token": "mock_access_token", "expires": 3600, "refresh_token": "mock_refresh_token", "uid": 1}');
+
+        $client = m::mock('Guzzle\Service\Client');
+        $client->shouldReceive('setBaseUrl')->times(1);
+        $client->shouldReceive('post->send')->times(1)->andReturn($response);
+        $this->provider->setHttpClient($client);
+
+        $token = $this->provider->getAccessToken('client_credentials');
+        $this->assertInstanceOf('League\OAuth2\Client\Token\AccessToken', $token);
+
+        $grant = new \League\OAuth2\Client\Grant\ClientCredentials();
+        $this->assertEquals('client_credentials', (string) $grant);
+    }
+}
diff --git a/test/src/Grant/PasswordTest.php b/test/src/Grant/PasswordTest.php
new file mode 100644
index 0000000..4070b12
--- /dev/null
+++ b/test/src/Grant/PasswordTest.php
@@ -0,0 +1,68 @@
+<?php
+
+namespace League\OAuth2\Client\Test\Grant;
+
+use \Mockery as m;
+
+class PasswordTest extends \PHPUnit_Framework_TestCase
+{
+    protected $provider;
+
+    protected function setUp()
+    {
+        $this->provider = new \League\OAuth2\Client\Provider\Google(array(
+            'clientId' => 'mock_client_id',
+            'clientSecret' => 'mock_secret',
+            'redirectUri' => 'none',
+        ));
+    }
+
+    public function testGetAccessToken()
+    {
+        $response = m::mock('Guzzle\Http\Message\Response');
+        $response->shouldReceive('getBody')->times(2)->andReturn('{"access_token": "mock_access_token", "expires": 3600, "refresh_token": "mock_refresh_token", "uid": 1}');
+
+        $client = m::mock('Guzzle\Service\Client');
+        $client->shouldReceive('setBaseUrl')->times(1);
+        $client->shouldReceive('post->send')->times(1)->andReturn($response);
+        $this->provider->setHttpClient($client);
+
+        $token = $this->provider->getAccessToken('password', array('username' => 'mock_username', 'password' => 'mock_password'));
+        $this->assertInstanceOf('League\OAuth2\Client\Token\AccessToken', $token);
+
+        $grant = new \League\OAuth2\Client\Grant\Password();
+        $this->assertEquals('password', (string) $grant);
+    }
+
+    /**
+     * @expectedException BadMethodCallException
+     */
+    public function testInvalidUsername()
+    {
+        $response = m::mock('Guzzle\Http\Message\Response');
+        $response->shouldReceive('getBody')->times(2)->andReturn('{"access_token": "mock_access_token", "expires": 3600, "refresh_token": "mock_refresh_token", "uid": 1}');
+
+        $client = m::mock('Guzzle\Service\Client');
+        $client->shouldReceive('setBaseUrl')->times(1);
+        $client->shouldReceive('post->send')->times(1)->andReturn($response);
+        $this->provider->setHttpClient($client);
+
+        $this->provider->getAccessToken('password', array('invalid_username' => 'mock_username', 'password' => 'mock_password'));
+    }
+
+    /**
+     * @expectedException BadMethodCallException
+     */
+    public function testInvalidPassword()
+    {
+        $response = m::mock('Guzzle\Http\Message\Response');
+        $response->shouldReceive('getBody')->times(2)->andReturn('{"access_token": "mock_access_token", "expires": 3600, "refresh_token": "mock_refresh_token", "uid": 1}');
+
+        $client = m::mock('Guzzle\Service\Client');
+        $client->shouldReceive('setBaseUrl')->times(1);
+        $client->shouldReceive('post->send')->times(1)->andReturn($response);
+        $this->provider->setHttpClient($client);
+
+        $this->provider->getAccessToken('password', array('username' => 'mock_username', 'invalid_password' => 'mock_password'));
+    }
+}