diff --git a/lib/authenticate.js b/lib/authenticate.js
index 5cbb93761e2..35c92b42674 100644
--- a/lib/authenticate.js
+++ b/lib/authenticate.js
@@ -51,6 +51,11 @@ var authenticate = function(client, username, password, options, callback) {
       if (err) return handleCallback(callback, err, false);
       _callback(null, true);
     });
+  } else if (authMechanism === 'SCRAM-SHA-256') {
+    client.topology.auth('scram-sha-256', authdb, username, password, function(err) {
+      if (err) return handleCallback(callback, err, false);
+      _callback(null, true);
+    });
   } else if (authMechanism === 'GSSAPI') {
     if (process.platform === 'win32') {
       client.topology.auth('sspi', authdb, username, password, options, function(err) {
@@ -95,6 +100,7 @@ module.exports = function(self, username, password, options, callback) {
     options.authMechanism !== 'MONGODB-CR' &&
     options.authMechanism !== 'MONGODB-X509' &&
     options.authMechanism !== 'SCRAM-SHA-1' &&
+    options.authMechanism !== 'SCRAM-SHA-256' &&
     options.authMechanism !== 'PLAIN'
   ) {
     return handleCallback(
diff --git a/lib/db.js b/lib/db.js
index 937efcd6352..75763784cc8 100644
--- a/lib/db.js
+++ b/lib/db.js
@@ -1189,22 +1189,28 @@ var _executeAuthCreateUserCommand = function(self, username, password, options,
     roles = ['dbOwner'];
   }
 
+  const digestPassword = self.s.topology.lastIsMaster().maxWireVersion >= 7;
+
   // Build the command to execute
   var command = {
     createUser: username,
     customData: customData,
     roles: roles,
-    digestPassword: false
+    digestPassword
   };
 
   // Apply write concern to command
   command = applyWriteConcern(command, { db: self }, options);
 
-  // Use node md5 generator
-  var md5 = crypto.createHash('md5');
-  // Generate keys used for authentication
-  md5.update(username + ':mongo:' + password);
-  var userPassword = md5.digest('hex');
+  let userPassword = password;
+
+  if (!digestPassword) {
+    // Use node md5 generator
+    let md5 = crypto.createHash('md5');
+    // Generate keys used for authentication
+    md5.update(username + ':mongo:' + password);
+    userPassword = md5.digest('hex');
+  }
 
   // No password
   if (typeof password === 'string') {
diff --git a/lib/mongo_client.js b/lib/mongo_client.js
index 547c7898001..a2a63dc6981 100644
--- a/lib/mongo_client.js
+++ b/lib/mongo_client.js
@@ -778,7 +778,7 @@ function createServer(self, options, callback) {
   var collectedEvents = collectEvents(self, servers[0]);
 
   // Connect to topology
-  servers[0].connect(function(err, topology) {
+  servers[0].connect(options, function(err, topology) {
     if (err) return callback(err);
     // Clear out all the collected event listeners
     clearAllEvents(servers[0]);
diff --git a/lib/url_parser.js b/lib/url_parser.js
index af8c1bc7cca..8ced4f11b12 100644
--- a/lib/url_parser.js
+++ b/lib/url_parser.js
@@ -484,6 +484,7 @@ function parseConnectionString(url, options) {
           value !== 'MONGODB-CR' &&
           value !== 'DEFAULT' &&
           value !== 'SCRAM-SHA-1' &&
+          value !== 'SCRAM-SHA-256' &&
           value !== 'PLAIN'
         )
           throw new Error(
diff --git a/test/functional/saslprep_tests.js b/test/functional/saslprep_tests.js
new file mode 100644
index 00000000000..1bb21c86da9
--- /dev/null
+++ b/test/functional/saslprep_tests.js
@@ -0,0 +1,94 @@
+'use strict';
+
+const setupDatabase = require('./shared').setupDatabase;
+const withClient = require('./shared').withClient;
+
+describe('SASLPrep', function() {
+  // Step 4
+  // To test SASLprep behavior, create two users:
+  // username: "IX", password "IX"
+  // username: "u2168" (ROMAN NUMERAL NINE), password "u2163" (ROMAN NUMERAL FOUR)
+  // To create the users, use the exact bytes for username and password without SASLprep or other normalization and specify SCRAM-SHA-256 credentials:
+  // db.runCommand({createUser: 'IX', pwd: 'IX', roles: ['root'], mechanisms: ['SCRAM-SHA-256']}) db.runCommand({createUser: 'u2168', pwd: 'u2163', roles: ['root'], mechanisms: ['SCRAM-SHA-256']})
+  // For each user, verify that the driver can authenticate with the password in both SASLprep normalized and non-normalized forms:
+  // User "IX": use password forms "IX" and "Iu00ADX"
+  // User "u2168": use password forms "IV" and "Iu00ADV"
+  // As a URI, those have to be UTF-8 encoded and URL-escaped, e.g.:
+  // mongodb://IX:IX@mongodb.example.com/admin
+  // mongodb://IX:I%C2%ADX@mongodb.example.com/admin
+  // mongodb://%E2%85%A8:IV@mongodb.example.com/admin
+  // mongodb://%E2%85%A8:I%C2%ADV@mongodb.example.com/admin
+
+  const users = [
+    {
+      username: 'IX',
+      password: 'IX',
+      mechanisms: ['SCRAM-SHA-256']
+    },
+    {
+      username: '\u2168',
+      password: '\u2163',
+      mechanisms: ['SCRAM-SHA-256']
+    }
+  ];
+
+  before(function() {
+    return setupDatabase(this.configuration);
+  });
+
+  before(function() {
+    return withClient(this.configuration.newClient(), client => {
+      const db = client.db('admin');
+
+      const createUserCommands = users.map(user => ({
+        createUser: user.username,
+        pwd: user.password,
+        roles: ['root'],
+        mechanisms: user.mechanisms
+      }));
+
+      return Promise.all(createUserCommands.map(cmd => db.command(cmd)));
+    });
+  });
+
+  after(function() {
+    return withClient(this.configuration.newClient(), client => {
+      const db = client.db('admin');
+
+      return Promise.all(users.map(user => db.removeUser(user.username)));
+    });
+  });
+
+  [
+    { username: 'IX', password: 'IX' },
+    { username: 'IX', password: 'I\u00ADX' },
+    { username: 'IX', password: '\u2168' },
+    { username: '\u2168', password: 'IV' },
+    { username: '\u2168', password: 'I\u00ADV' },
+    { username: '\u2168', password: '\u2163' }
+  ].forEach(user => {
+    const username = user.username;
+    const password = user.password;
+
+    it(`should be able to login with username "${username}" and password "${password}"`, {
+      metadata: {
+        requires: {
+          mongodb: '>=3.7.3',
+          node: '>=6'
+        }
+      },
+      test: function() {
+        const options = {
+          user: username,
+          password: password,
+          authSource: 'admin',
+          authMechanism: 'SCRAM-SHA-256'
+        };
+
+        return withClient(this.configuration.newClient(options), client => {
+          return client.db('admin').stats();
+        });
+      }
+    });
+  });
+});
diff --git a/test/functional/scram_sha_256_tests.js b/test/functional/scram_sha_256_tests.js
new file mode 100644
index 00000000000..02a2eb6c168
--- /dev/null
+++ b/test/functional/scram_sha_256_tests.js
@@ -0,0 +1,216 @@
+'use strict';
+
+const expect = require('chai').expect;
+const sinon = require('sinon');
+const ScramSHA256 = require('mongodb-core').ScramSHA256;
+const MongoError = require('mongodb-core').MongoError;
+const setupDatabase = require('./shared').setupDatabase;
+const withClient = require('./shared').withClient;
+const MongoClient = require('../../lib/mongo_client');
+
+describe('SCRAM-SHA-256 auth', function() {
+  const test = {};
+  const userMap = {
+    sha1: {
+      description: 'user with sha1 credentials',
+      username: 'sha1',
+      password: 'sha1',
+      mechanisms: ['SCRAM-SHA-1']
+    },
+    sha256: {
+      description: 'user with sha256 credentials',
+      username: 'sha256',
+      password: 'sha256',
+      mechanisms: ['SCRAM-SHA-256']
+    },
+    both: {
+      description: 'user with both credentials',
+      username: 'both',
+      password: 'both',
+      mechanisms: ['SCRAM-SHA-1', 'SCRAM-SHA-256']
+    }
+  };
+
+  function makeConnectionString(config, username, password) {
+    return `mongodb://${username}:${password}@${config.host}:${config.port}/${config.db}?`;
+  }
+
+  const users = Object.keys(userMap).map(name => userMap[name]);
+
+  afterEach(() => test.sandbox.restore());
+
+  before(function() {
+    test.sandbox = sinon.sandbox.create();
+    return setupDatabase(this.configuration);
+  });
+
+  before(function() {
+    return withClient(this.configuration.newClient(), client => {
+      test.oldDbName = this.configuration.db;
+      this.configuration.db = 'admin';
+      const db = client.db(this.configuration.db);
+
+      const createUserCommands = users.map(user => ({
+        createUser: user.username,
+        pwd: user.password,
+        roles: ['root'],
+        mechanisms: user.mechanisms
+      }));
+
+      return Promise.all(createUserCommands.map(cmd => db.command(cmd)));
+    });
+  });
+
+  after(function() {
+    return withClient(this.configuration.newClient(), client => {
+      const db = client.db(this.configuration.db);
+      this.configuration.db = test.oldDbName;
+
+      return Promise.all(users.map(user => db.removeUser(user.username)));
+    });
+  });
+
+  //   Step 2
+  // For each test user, verify that you can connect and run a command requiring authentication for the following cases:
+  // Explicitly specifying each mechanism the user supports.
+  // Specifying no mechanism and relying on mechanism negotiation.
+  // For the example users above, the dbstats command could be used as a test command.
+  users.forEach(user => {
+    user.mechanisms.forEach(mechanism => {
+      it(`should auth ${user.description} when explicitly specifying ${mechanism}`, {
+        metadata: { requires: { mongodb: '>=3.7.3' } },
+        test: function() {
+          const options = {
+            user: user.username,
+            password: user.password,
+            authMechanism: mechanism,
+            authSource: this.configuration.db
+          };
+
+          return withClient(this.configuration.newClient(options), client => {
+            return client.db(this.configuration.db).stats();
+          });
+        }
+      });
+
+      it(`should auth ${user.description} when explicitly specifying ${mechanism} in url`, {
+        metadata: { requires: { mongodb: '>=3.7.3' } },
+        test: function() {
+          const username = encodeURIComponent(user.username);
+          const password = encodeURIComponent(user.password);
+
+          const url = `${makeConnectionString(
+            this.configuration,
+            username,
+            password
+          )}authMechanism=${mechanism}`;
+
+          const client = new MongoClient(url);
+
+          return withClient(client, client => {
+            return client.db(this.configuration.db).stats();
+          });
+        }
+      });
+    });
+
+    it(`should auth ${user.description} using mechanism negotiaton`, {
+      metadata: { requires: { mongodb: '>=3.7.3' } },
+      test: function() {
+        const options = {
+          user: user.username,
+          password: user.password,
+          authSource: this.configuration.db
+        };
+
+        return withClient(this.configuration.newClient(options), client => {
+          return client.db(this.configuration.db).stats();
+        });
+      }
+    });
+
+    it(`should auth ${user.description} using mechanism negotiaton and url`, {
+      metadata: { requires: { mongodb: '>=3.7.3' } },
+      test: function() {
+        const username = encodeURIComponent(user.username);
+        const password = encodeURIComponent(user.password);
+        const url = makeConnectionString(this.configuration, username, password);
+
+        const client = new MongoClient(url);
+
+        return withClient(client, client => {
+          return client.db(this.configuration.db).stats();
+        });
+      }
+    });
+  });
+
+  // For a test user supporting both SCRAM-SHA-1 and SCRAM-SHA-256,
+  // drivers should verify that negotation selects SCRAM-SHA-256..
+  it('should select SCRAM-SHA-256 for a user that supports both auth mechanisms', {
+    metadata: { requires: { mongodb: '>=3.7.3' } },
+    test: function() {
+      const options = {
+        user: userMap.both.username,
+        password: userMap.both.password,
+        authSource: this.configuration.db
+      };
+
+      test.sandbox.spy(ScramSHA256.prototype, 'auth');
+
+      return withClient(this.configuration.newClient(options), () => {
+        expect(ScramSHA256.prototype.auth.calledOnce).to.equal(true);
+      });
+    }
+  });
+
+  // Step 3
+  // For test users that support only one mechanism, verify that explictly specifying the other mechanism fails.
+  it('should fail to connect if incorrect auth mechanism is explicitly specified', {
+    metadata: { requires: { mongodb: '>=3.7.3' } },
+    test: function() {
+      const options = {
+        user: userMap.sha256.username,
+        password: userMap.sha256.password,
+        authSource: this.configuration.db,
+        authMechanism: 'SCRAM-SHA-1'
+      };
+
+      return withClient(
+        this.configuration.newClient(options),
+        () => Promise.reject('This request should have failed to authenticate'),
+        err => expect(err).to.not.be.null
+      );
+    }
+  });
+
+  // For a non-existent username, verify that not specifying a mechanism when connecting fails with the same error
+  // type that would occur with a correct username but incorrect password or mechanism. (Because negotiation with
+  // a non-existent user name causes an isMaster error, we want to verify this is seen by users as similar to other
+  // authentication errors, not as a network or database command error.)
+  it('should fail for a nonexistent username with same error type as bad password', {
+    metadata: { requires: { mongodb: '>=3.7.3' } },
+    test: function() {
+      const noUsernameOptions = {
+        user: 'roth',
+        password: 'pencil',
+        authSource: 'admin'
+      };
+
+      const badPasswordOptions = {
+        user: 'both',
+        password: 'pencil',
+        authSource: 'admin'
+      };
+
+      const getErrorMsg = options =>
+        withClient(
+          this.configuration.newClient(options),
+          () => Promise.reject('This request should have failed to authenticate'),
+          err => expect(err).to.be.an.instanceof(MongoError)
+        );
+
+      return Promise.all([getErrorMsg(noUsernameOptions), getErrorMsg(badPasswordOptions)]);
+    }
+  });
+});
diff --git a/test/functional/shared.js b/test/functional/shared.js
index f3f92d39122..ca21418279b 100644
--- a/test/functional/shared.js
+++ b/test/functional/shared.js
@@ -39,6 +39,33 @@ function setupDatabase(configuration, dbsToClean) {
     );
 }
 
+function makeCleanupFn(client) {
+  return function(err) {
+    return new Promise((resolve, reject) => {
+      try {
+        client.close(closeErr => {
+          const finalErr = err || closeErr;
+          if (finalErr) {
+            return reject(finalErr);
+          }
+          return resolve();
+        });
+      } catch (e) {
+        return reject(err || e);
+      }
+    });
+  };
+}
+
+function withClient(client, operation, errorHandler) {
+  const cleanup = makeCleanupFn(client);
+
+  return client
+    .connect()
+    .then(operation, errorHandler)
+    .then(() => cleanup(), cleanup);
+}
+
 var assert = {
   equal: function(a, b) {
     expect(a).to.equal(b);
@@ -77,5 +104,6 @@ module.exports = {
   connectToDb: connectToDb,
   setupDatabase: setupDatabase,
   assert: assert,
-  delay: delay
+  delay: delay,
+  withClient
 };