No matter how much you’re earning, an emergency fund is a critical component to your financial health. But if you don’t even have enough cash to cover a $400 expense, how are you supposed to build an emergency fund?

If money is tight, the key is to build your savings gradually. Most experts recommend saving enough to cover three to sex months’ worth of expenses, in case you lose your job. You don’t need to come up with that cash overnight, but you may need to make some sacrifices, so you have something to put toward your emergency fund each month while still paying all your bills.

Start by tracking your expenses to get a clear idea of how you’re spending your money each month. (If that sounds tedious, there are several apps that track your money for you and update you on where your money is going.) Once you know where you’re spending your cash, see if there are areas where you can make cuts. Eliminate any unnecessary costs, then consider whether you can live without some of the nice-to-have costs too.

One thing to keep in mind when establishing an emergency fund is that these sacrifices will be temporary – once you reach your goal, your budget can go back to normal. So if you’re balking at the sacrifices you’d need to make, just remember that it won’t last forever.

When you’ve got a long list of bills to pay, building an emergency fund may not seem like the most pressing task. But you never know when an unexpected expense is going to pop up, and an emergency fund can prepare your for any financial obstacle you may face.