Want a mortgage? If so, you better aim to get your credit score above 650, if not 700.

Data from the Federal Reserve show that 9 out of 10 U.S. mortgages go to borrowers with a score of 650 or better. Three quarters go to borrowers with scores of better than 700.

Any credit score between 670 and 739 is considered “good,” according to credit rating agency Experian. The national average score as of last December was 704, meaning that the large majority of mortgages go to Americans with better-than-average credit. Americans credit scores also vary widely by age. The average among 18 to 29 year olds is just 659, which suggests many consumers in their 20s may have a harder time finding a mortgage lender than older Americans.

The credit scores lenders target, according to the Fed’s data, are higher than the official minimum of 620 for loans backed by government agencies Fannie Mae and Freddie Mac, the cheapest option for many homeowners. A popular option for first-time homebuyers is mortgages backed by the Federal Housing Administration, which you can qualify for with a score as low as 500 if you can also make down payment of at least 10%.

Keith Gumbinger, vice president at mortgage site HSH.com, says the sweet spot for most would-be homeowners is 700 to 720. Borrowers with credit scores below that level could face problems, like high interest rates and lower caps on the amount lenders will allow them to borrow. “You can get a mortgage with a low credit score,” he says. “But it may not be beneficial to your [home buying] transaction.”

Lenders are also far stricter today than in the years leading up to the 2008 housing bust, when the median loan went to borrowers with credit scores of around 700 and about 10% of borrowers were well below 600.

Worried you won’t qualify?

There are a number of ways to boost your credit score. Paying your bills on time matters, obviously. But so do factors like the length of your credit history and the amount of unused credit available to you.