YNAB is extremely customizable and there are many ways to have an emergency fund within the application. However, there are basically 3 methods and each have their own Pros and Cons.
Option 1: Off-Budget Tracking "Asset" Savings Account funded by an Emergency Fund category
To do this method you simply create a Savings account at your bank for your emergency fund and add this account as a tracking account with the "Asset" type. You then fund this account every month with an "Emergency Fund" Savings category until it reaches the desired amount. Then when you have the desired amount in this savings account, whenever there's a true emergency you transfer money into your on-budget account to budget with.Pros
- It's hard to move money out so you're not tempted to use the money for things that aren't really emergencies
- Keeps it off budget so you're not tempted to use it and you basically forget about it once it's full
- Savings accounts only allow 3 transfers out a month usually (but again this may be a good thing as it discourages you from using it)
Option 2: Emergency Fund category within an On-Budget Checking or Savings Account
Simply create a budget category under your Category Group "SAVINGS" called "Emergency Fund". Then simply add to that category as you can each month until you reach your desired balance of 3 to 6 months of expenses. You can even create a "Goal" within YNAB to help you reach that desired level of funds.
Pros
- Very easy to set up in YNAB
- Very easy to move money out to other budget categories during emergencies
- A little TOO easy to move money out to other budget categories during emergencies which means you'll be tempted to move money out when it's not really an emergency
Option 3: Many Emergency Fund Categories within an Emergency Fund Category Group
Simply create a new Category Group called "EMERGENCY FUND" and create individual categories for each type of emergency under that. You can even set goals for each category as well.
Pros
- Very easy to set up
- You know exactly that you have money to cover each type of emergency
- Taking money from one emergency fund doesn't make you less secure or another type of emergency
- Similar to option 2, it's still a little TOO easy to move money out to other budget categories during emergencies which means you'll be tempted to move money out when it's not really an emergency