Philadelphia, which has the highest overall poverty rate among the nation's 10-largest cities, also leads that group in poverty among residents 60 or older. About one in 10 older Philadelphians are in deep poverty, which for a household of one is defined as annual income of about $6,000 or less. For nearly half of older Philadelphians, annual income is no more than twice the poverty level, which is about $24,000 for a household of one.