Click on the My Teams Tab on the Left Navigation toolbar.
Scroll down the Edit Your Team Information. Click on the drop down box under Password Expire Policy. This policy will force your team users (members) to update their passwords when an option other than disabled is selected. You can choose either, disabled (which is the default setting, or 1, 3, 6 or 12 months) then click Save Team Information.
Same 7 previous used passwords can NOT be used if Password Expire Policy is set on 1, 3, 6 or 12 months. If disabled, your users can use the same passwords if needed.