You can view your past budgets to see if you hit your targets in previous months. You can't edit a past month's budget.
Currently, this isn't available on Android devices. But Android users can sign in at Mint.com and follow the web instructions below.
Select your Mint experience for instructions:
Mint iOS app
- Open the app and select Monthly from the bottom menu
- Select this month’s budget
- Select the month you’d like to view from the list at the top of the screen
Mint web
- Sign in to Mint.com and select Budgets from the side menu
- Using the timeline at the top of the page, select the past month you’d like to view