The Federal Reserve said on Thursday that its annual tests of the financial strength of the 18 largest banks in the United States revealed that each had enough capital to justify paying some of it out to shareholders.

The clean bill of health is good news for big banks and their shareholders, but it could fuel concerns that federal regulators are embracing a laissez-faire approach to financial oversight.

There was one caveat to the Fed’s across-the-board thumbs-up: The central bank said it found weaknesses in how Credit Suisse was measuring potential losses, and the Fed therefore capped the amount of money the Swiss bank could return to its investors until it corrected the problem.

The Fed’s “stress tests” examine how the largest banks would fare in a severe economic downturn or a sudden shock to the global financial markets. After a two-part evaluation, banks either receive permission to return capital — via repurchasing their own shares, paying dividends or other means — or are prohibited from doing so until they fortify their capital cushions or strengthen their management.