NEW YORK ( TheStreet) - American Express ( AXP) passed the Federal Reserve's 'stress test' for a second time on Thursday, winning clearance to return billions of dollars to investors through a dividend increase and share buyback valued at about $3.2 billion. American Express benefited from the Fed's decision to methodology used to determine whether 18 of the country's largest lenders are sufficiently capitalized. If the Fed hadn't taken such actions, American Express risked having to wait to return capital to investors until later in the year. According to the Fed, American Express may have had its plan rejected had the credit card lender not been able to adjust the amount of money it aimed to divert to shareholders. Following a give-and-take between the company and the regulator, America Express will increase its quarterly dividend to 23 cents per share and repurchase $3.2 billion in shares for the last three quarters of 2013, and spend another $1 billion in the first quarter of 2014. American Express' adjusted plan will put the lender at a stressed capital ratio of 6.42%, according to the Fed's calculations, far above the regulator's minimum 5% threshold. The company's initial plan would have put the firm at a 4.97% capital ratio, tantamount to a failing grade. A press release issued by American Express indicates the firm's initial capital plan submitted in January included a quarterly dividend of 23 cents and a share repurchase program of up to $4.7 billion for the last three quarters of 2013 and up to $1 billion in the first quarter of 2014. Since that plan would have put American Express below the Fed's threshold, the credit card lender was forced to temper its share buyback aspirations. The ability to revise its capital plan and get a second chance at returning capital to investors contrasts to last year's tests when the Fed failed Citigroup ( C) outright for an overaggressive share buyback plan. The difference in American Express's initial capital plan versus the one approved by the Fed hinged on just $1.5 billion in share buybacks. While American Express's second chance at tests doesn't represent any special treatment - all other lenders also had the ability to resubmit plans were the Fed to have different calculations - it also indicates just how scarce capital might be for lenders in the Fed's stressed scenario. By taking repurchases from $4.7 billion to $3.2 billion, American Express was able to improve its stressed capital ratio from 4.97% to 6.42%. Marina Norville, an American Express spokesperson declined to comment beyond the firms press release announcing a dividend increase and share buyback. American Express shares rose 17 cents in after-hours trading, adding to year-to-date gains in excess of 13%.