Form 8606 for Australians in 2026: Essential Guide for Expats

Form 8606 is an official document from the US Internal Revenue Service (IRS) designed to track after-tax (non-deductible) contributions to traditional IRAs. It also records conversions from traditional IRAs to Roth IRAs and distributions from accounts that include after-tax contributions.

If you make after-tax contributions to a traditional IRA, you must file Form 8606 for each year you contribute. This ensures that, when you eventually withdraw funds, you are not taxed again on money you have already paid tax on. Failing to file can result in double taxation and potential penalties.

Who Needs to File Form 8606?

You may need to file Form 8606 if you:

• Make non-deductible contributions to a traditional IRA while living or working in the US.
• Convert a traditional IRA to a Roth IRA (sometimes called a "backdoor Roth").
• Take distributions from an IRA that includes after-tax contributions.

Even if you have returned to Australia, if you still hold a US IRA with non-deductible contributions, you may need to file Form 8606 to maintain accurate records with the IRS.

Australians working in the US or holding US retirement accounts face unique tax challenges. The Australian Taxation Office (ATO) treats US IRAs differently from Australian superannuation funds, and distributions may be taxable in both countries. Properly filing Form 8606 helps you:

• Avoid being taxed twice on the same contributions.
• Provide evidence for claiming foreign tax credits.
• Maintain compliance with both US and Australian tax authorities.

Recent changes to US retirement account rules mean that Form 8606 remains highly relevant for Australians in 2026. While contribution limits and eligibility criteria may change over time, the need to accurately track after-tax contributions and conversions remains constant.

Increased IRS Penalties

The IRS has increased penalties for failing to file Form 8606 when required. This makes it even more important to keep up with your filings, especially if you have made non-deductible contributions or conversions in previous years.

Cross-Border Tax Implications

Because the ATO and IRS have different approaches to retirement accounts, accurate US paperwork can help you:

• Support your claims for foreign tax credits.
• Avoid confusion or disputes over taxable income.
• Demonstrate compliance if your tax situation is reviewed by either authority.

Making After-Tax Contributions in the US

If you are working in the US and contribute to a traditional IRA with after-tax dollars, you must file Form 8606 for each year you make these contributions. This record ensures that, when you take distributions in the future, you are not taxed again on the same money.

Using the Backdoor Roth IRA Strategy

Some Australians in the US may not qualify for direct Roth IRA contributions due to income limits. Instead, they may use the "backdoor Roth" strategy: making a non-deductible contribution to a traditional IRA, then converting it to a Roth IRA. Form 8606 is required to document both the contribution and the conversion, ensuring the IRS recognises the after-tax status of the funds.

Returning to Australia with a US IRA

If you return to Australia but leave your US IRA in place, you may eventually take distributions from the account. If you have made non-deductible contributions in the past, having a complete record of Form 8606 filings is essential to avoid double taxation by both the IRS and the ATO.

Here are practical steps for Australians managing US IRAs in 2026:

1. Keep Detailed Records

Maintain documentation of all IRA contributions, conversions, and distributions. This includes:

• Annual statements from your IRA provider
• Copies of all filed Form 8606 documents
• Records of any Roth conversions

2. File Form 8606 When Required

You must file Form 8606 for any year in which you:

• Make non-deductible contributions to a traditional IRA
• Convert a traditional IRA to a Roth IRA
• Take distributions from an IRA that includes after-tax contributions

Missing a required filing can result in penalties and complicate your tax situation.

3. Coordinate with Your Australian Tax Obligations

The ATO may treat US IRA distributions differently from superannuation withdrawals. Keeping your US tax paperwork in order can help you:

• Claim foreign tax credits
• Avoid double taxation
• Provide evidence if your tax situation is reviewed

If you need guidance, consider consulting a professional with experience in both US and Australian tax systems. You can also learn more about working with professionals at [/insurance/personal/insurance-brokers].

4. Don’t Ignore IRS Notices

If you receive a notice from the IRS regarding missing or incomplete Form 8606 filings, respond promptly. Addressing issues early can help you avoid escalating penalties and interest.

What happens if I forget to file Form 8606?

If you fail to file Form 8606 when required, you may face IRS penalties and risk being taxed twice on your after-tax contributions.

Do I need to file Form 8606 if I no longer live in the US?

Yes, if you have a US IRA with non-deductible contributions or take distributions from such an account, you may still need to file Form 8606, even as a non-resident.

How does Form 8606 affect my Australian tax return?

While Form 8606 is a US tax document, maintaining accurate records can help you claim foreign tax credits and avoid double taxation when reporting to the ATO.

Can I file Form 8606 for previous years if I missed it?

Yes, you can file Form 8606 for prior years, but you may be subject to penalties. It’s best to address any missed filings as soon as possible.

For Australians with US retirement accounts, Form 8606 is more than just paperwork—it’s a safeguard against double taxation and a key part of cross-border financial planning. By understanding your obligations and keeping your records up to date, you can protect your savings and stay compliant in 2026 and beyond.