| The 401(k) plan cannot be "rolled over" into an Australian plan. You may be able to avoid U.S. tax on the 401(k) distribution if the distribution is considered a "pension" distribution under the U.S.-Australia income tax treaty. See Article 18 of the Treaty.
Whether the distribution is considered a pension distribution depends on several factors, including age, length of employment, and death, disability or separation of service (ideally retirement). If you are under age 55, it is unlikely that a lump sum distribution from a 401(k) would qualify as a pension distribution under the Treaty.
Even if you meet requirements, the 401(k) administrator may decide to withhold U.S. tax (if they don't withhold and it turns out they should have, they can be held liable for the tax). If the administrator withholds and you believe that the distribution should qualify as a pension, then you can file a U.S. tax return to request a refund of the taxes withheld.
It may be possible to get a ruling from the IRS in advance to confirm that the distribution should be treated as a pension distribution. See, for instance, Private Letter Ruling 200416008. |