You can take your ex back to court.  Once there, the judge has many tools available for your use.  For example, you could have the judge issue a wage assignment which results in an automatic deduction from your spouse’s paycheck.  You may also be able to “attach” or “levy” upon your spouse’s bank accounts, stocks or other property including a house.  In addition, many states have empowered the local district attorneys office with the power to enforce support payments.  Accordingly, you could hand the matter over to the district attorney’s office or a similar government office to pursue your spouse.  Many courthouses offer free services that give advice on the best strategy to use.