Federal officials have overhauled Medicare billing statements to make it easier to find bogus charges. And for those who might need an incentive to scour their bills, the new statements promise a reward of up to $1,000 for a tip that leads to uncovering fraud. Although the bonus isn't new, there's no mention of it on current forms, which are sent to about 36 million beneficiaries in traditional Medicare. The new, more consumer-friendly format, which goes online Saturday, includes larger type and explanations of medical services.