((a)) ** .—** The remedies available to the United States under this chapter may be enforced against property which is co-owned by a debtor and any other person only to the extent allowed by the law of the State where the property is located. This section shall not be construed to limit any right or interest of a debtor or co-owner in a retirement system for Federal military or civilian personnel established by the United States or any agency thereof or in a qualified retirement arrangement.

((b)) ** .—** For purposes of subsection (a)—

((1)) the term “retirement system for Federal military or civilian personnel” means a pension or annuity system for Federal military or civilian personnel of more than one agency, or for some or all of such personnel of a single agency, established by statute or by regulation pursuant to statutory authority; and

((2)) the term “qualified retirement arrangement” means a plan qualified under section 401(a), 403(a), or 409 of the Internal Revenue Code of 1986 or a plan that is subject to the requirements of section 205 of the Employee Retirement Income Security Act of 1974.