diff --git a/test/api/v3/integration/groups/POST-groups.test.js b/test/api/v3/integration/groups/POST-groups.test.js
index 8036d6b0d8..ad8f7a6c92 100644
--- a/test/api/v3/integration/groups/POST-groups.test.js
+++ b/test/api/v3/integration/groups/POST-groups.test.js
@@ -189,6 +189,17 @@ describe('POST /group', () => {
       expect(updatedUser.party._id).to.eql(party._id);
     });
 
+    it('does not award Party Up achievement to solo partier', async () => {
+      await user.post('/groups', {
+        name: partyName,
+        type: partyType,
+      });
+
+      let updatedUser = await user.get('/user');
+
+      expect(updatedUser.achievements.partyUp).to.not.eql(true);
+    });
+
     it('prevents user in a party from creating another party', async () => {
       await user.post('/groups', {
         name: partyName,
diff --git a/test/api/v3/integration/groups/POST-groups_groupId_join.test.js b/test/api/v3/integration/groups/POST-groups_groupId_join.test.js
index c245bee42a..60a44bc3f3 100644
--- a/test/api/v3/integration/groups/POST-groups_groupId_join.test.js
+++ b/test/api/v3/integration/groups/POST-groups_groupId_join.test.js
@@ -225,4 +225,53 @@ describe('POST /group/:groupId/join', () => {
       });
     });
   });
+
+  context('Party incentive achievements', () => {
+    let leader, member, party;
+
+    beforeEach(async () => {
+      leader = await generateUser();
+      member = await generateUser();
+      party = await leader.post('/groups', {
+        name: 'Testing Party',
+        type: 'party',
+      });
+      await leader.post(`/groups/${party._id}/invite`, {
+        uuids: [member._id],
+      });
+      await member.post(`/groups/${party._id}/join`);
+    });
+
+    it('awards Party Up achievement to party of size 2', async () => {
+      await member.sync();
+      await leader.sync();
+
+      expect(member).to.have.deep.property('achievements.partyUp', true);
+      expect(leader).to.have.deep.property('achievements.partyUp', true);
+    });
+
+    it('does not award Party On achievement to party of size 2', async () => {
+      await member.sync();
+      await leader.sync();
+
+      expect(member).to.not.have.deep.property('achievements.partyOn');
+      expect(leader).to.not.have.deep.property('achievements.partyOn');
+    });
+
+    it('awards Party On achievement to party of size 4', async () => {
+      let addlMemberOne = await generateUser();
+      let addlMemberTwo = await generateUser();
+      await leader.post(`/groups/${party._id}/invite`, {
+        uuids: [addlMemberOne._id, addlMemberTwo._id],
+      });
+      await addlMemberOne.post(`/groups/${party._id}/join`);
+      await addlMemberTwo.post(`/groups/${party._id}/join`);
+
+      await member.sync();
+      await leader.sync();
+
+      expect(member).to.have.deep.property('achievements.partyOn', true);
+      expect(leader).to.have.deep.property('achievements.partyOn', true);
+    });
+  });
 });
diff --git a/website/src/controllers/api-v3/groups.js b/website/src/controllers/api-v3/groups.js
index 372e0c61fc..c979976206 100644
--- a/website/src/controllers/api-v3/groups.js
+++ b/website/src/controllers/api-v3/groups.js
@@ -295,6 +295,12 @@ api.joinGroup = {
 
     if (group.type === 'party' && inviter) {
       promises.push(User.update({_id: inviter}, {$inc: {'items.quests.basilist': 1}}).exec()); // Reward inviter
+      if (group.memberCount > 1) {
+        promises.push(User.update({$or: [{'party._id': group._id}, {_id: user._id}], 'achievements.partyUp': {$ne: true}}, {$set: {'achievements.partyUp': true}}, {multi: true}).exec());
+      }
+      if (group.memberCount > 3) {
+        promises.push(User.update({$or: [{'party._id': group._id}, {_id: user._id}], 'achievements.partyOn': {$ne: true}}, {$set: {'achievements.partyOn': true}}, {multi: true}).exec());
+      }
     }
 
     await Q.all(promises);