Most large banks appear to have been sailing through the annual “health checkups” they have had to undergo since the financial crisis.

But on Monday, the Federal Reserve, a prominent bank regulator, described some significant shortcomings in the banks’ responses to the so-called stress tests.

Despite the severity of the recent housing bust, the Fed said some banks weren’t taking into account the possibility of falling house prices when valuing certain mortgage-related assets for the tests.

In other cases, banks assumed they would be strong enough to take business away from competitors in stressed times.

The Fed’s findings are part of its efforts to improve the stress tests, which aim to ensure banks have the financial strength to withstand shocks in the economy and markets.

The tests have created tension between the Fed and the banks. One reason is that the tests can determine how much a bank is allowed to pay out in dividends or spend on stock buybacks.