Should US Expats in New Zealand Keep Their US Retirement Accounts?

Understanding US Retirement Accounts

US citizens and green card holders remain subject to US tax laws regardless of where they live. Retirement accounts such as 401(k)s, Traditional IRAs, and Roth IRAs offer tax advantages in the US, but those benefits may not always align with New Zealand’s tax system. Here’s how different US retirement accounts work:

• Traditional 401(k) & IRA: Contributions are tax-deferred, and withdrawals are taxed as ordinary income in the US.
• Roth IRA: Contributions are made post-tax, but qualified withdrawals are tax-free in the US.
• Pension Plans (TSP, SEP IRA, etc.): These follow similar taxation rules as 401(k) plans.

While these tax benefits are clear in the US, they may not always carry over seamlessly to New Zealand’s tax system.

New Zealand Tax on US Retirement Accounts

For US citizens residing in New Zealand, the tax treatment of US retirement accounts is a significant complexity. Because the US-New Zealand Tax Treaty does not contain a specific, comprehensive provision for the tax-free status of accounts like the 401(k) or Roth IRA, individuals often face challenges related to double taxation.

Tax on Withdrawals and Distributions

When you withdraw funds from a 401(k) or Traditional IRA, the IRS taxes the distribution at source. Because New Zealand lacks a specific treaty provision for these accounts, the IRD may also tax these withdrawals:

• Regular Withdrawals: These are generally treated as income and taxed at New Zealand’s progressive rates (up to 39%). You must often rely on Foreign Tax Credits (FTC) to mitigate paying twice.

• Early Withdrawals: If you withdraw before age 59½, you face a 10% IRS penalty. This penalty is not a tax that New Zealand will credit, resulting in a significantly higher total cost.

The 4-Year Transitional Residency Grace Period

New migrants or returning Kiwis (away for 10+ years) usually qualify for a 4-year temporary tax exemption on foreign income. During this 48-month window, you can generally withdraw or convert your US retirement funds without New Zealand taxing the lump sum. This is the optimal time to perform a Roth IRA conversion.

Roth IRA in NZ

It is vital to note that New Zealand does not recognize the tax-free nature of a Roth IRA. Even though the US considers a qualified Roth withdrawal tax-free, New Zealand may view it as taxable income. Expats should use the 2026 RAM method to track the cost basis of their Roth accounts to ensure they are only taxed on the growth portion in New Zealand, rather than the entire withdrawal.

2026 Updates: RAM and Scheme Pays

As of April 1, 2026, two major policy shifts have changed the strategy for expats.

1. Revenue Accounting Method (RAM)

The introduction of RAM allows eligible expats to be taxed only when income is realized (e.g., when a dividend is paid or an asset is sold). For those over the $50,000 NZD FIF threshold, this is a major improvement over the old Fair Dividend Rate (FDR) method, which taxed a flat 5% of the account value annually regardless of performance.

2. Scheme Pays Option

If you decide to transfer a foreign pension to a New Zealand scheme, the Scheme Pays rule allows the NZ provider to withhold a flat 28% tax directly from the transfer. This eliminates the need to pay a high marginal tax rate out-of-pocket from your personal savings.

Keeping Your US Retirement Accounts: Pros & Cons

Deciding whether to leave your 401(k) or IRA across the Pacific involves more than just tax math; it’s about balancing investment freedom against administrative complexity.

The Pros

• Continued US Tax Benefits: Your funds continue to grow tax-deferred (Traditional) or tax-free (Roth) from a US federal perspective.

• Access to Deep Markets: US brokerage accounts offer a vast range of low-cost ETFs and mutual funds that are often unavailable or significantly more expensive in New Zealand.

• Avoidance of PFIC Penalties: By keeping your money in US-domiciled funds, you avoid the IRS’s punitive Passive Foreign Investment Company (PFIC) rules, which apply to almost all New Zealand-based managed funds and KiwiSaver schemes.

• 2026 RAM Method: New Zealand’s new Revenue Accounting Method (RAM) allows you to be taxed only on “realized” income, making it easier to hold US assets without paying tax on paper gains you haven’t withdrawn yet.

The Cons

• Currency Exchange Risk: Your retirement buying power in New Zealand will fluctuate based on the USD/NZD exchange rate. A strong Kiwi dollar could effectively shrink your US savings.

• Double Taxation Hurdles: While the tax treaty provides for credits, you still face the administrative burden of filing in two countries and ensuring the timing of your credits aligns to avoid paying twice.

• Complexity Post-4-Year Window: Once your transitional residency ends, you must report these accounts to the IRD annually if they exceed the $50,000 NZD cost threshold.

• Account Restrictions: Some US financial institutions may freeze or close accounts if they detect you are no longer a US resident, potentially forcing a liquidation at an inopportune time.

Comparison: Keeping US Accounts vs. Moving to New Zealand

Below is a side-by-side overview of the key differences between retaining your accounts in the US versus transferring them to New Zealand. This highlights the potential tax implications, risks, and investment considerations to help inform your decision.