If you're a doctor who's late payingyour credit card bill, it's going tocost you more money. Credit cardissuers like Citigroup and MBNA havehiked up the charges for customerswho miss a payment due date. Thenumber of card issuers who charge atleast $35 for late payments has doubledover the past year. To makethings even more painful, card issuersare making it easier for you to miss apayment by cutting back on so-calledgrace periods—the time between theclosing date of your credit cardaccount cycle and when the paymentis due. Grace periods now averageanywhere between 20 and 25 days,down from 31 days in 1998.