According to the Fair Credit Reporting Act, delinquent accounts will stay on a report for a minimum of 7 years. If it is a "charge-off" meaning you didn't pay it, and let the debt ride until the time that the company effectively "writes it off", then the time period is 7 years plus 180 days from the date of the delinquency. If it is just some late payments for which you eventually caught back up, then it is just 7 years from the date u missed the payment. For more info go to http://credit.about.com/od/creditreportfaq/f/negativecrinfo.htm 
I just looked into this myself, and also found that credit companies have only a certain amount of time to take you to court/sue you regarding the account. It varies by state, from 3 to 10 years. To find the information for this regarding your state, go to http://www.creditcards.com/credit-card-news/credit-card-state-statute-limitations-1282.php and click on the state you live in for more information. This is different than the time limit for your credit report.