There is no limitation in the Bankruptcy Code as to how many times or how often a person can file bankruptcy. However, there is a limit as to how often a person can receive a discharge in bankruptcy. To determine eligibility to receive a discharge in a second bankruptcy case you must consider under which chapter each case was filed.
If a debtor files a Chapter 7 bankruptcy case and receives a discharge he cannot receive a discharge in a second Chapter 7 case for eight years and for four years in a Chapter 13 case. If a debtor files a Chapter 13 bankruptcy case and receives a discharge he cannot receive a discharge in a second Chapter 13 case for two years and for six years in a Chapter 7 case.
Notice that the time requirement limits the ability to receive a discharge in the second case but does not affect the ability to file a second bankruptcy. If the second case is a Chapter 7 case then the ability to file and the ability to receive a discharge amount to the same thing. There is no other valid purpose for filing a Chapter 7 case than to receive a discharge, so if the debtor cannot obtain a discharge in the Chapter 7 case then they are effectively barred from filing.
Chapter 13 cases have other benefits besides the discharge. Debtors may file Chapter 13 cases to protect secured property and allow them an opportunity to get caught up on arrears or to stop wage garnishment and allow them an opportunity to pay taxes or domestic support obligations over a longer period of time.