High-Net-Worth Individuals 401(k): Taxation, Rollovers, and Planning for Expats

Managing it effectively requires a strategic approach, particularly for internationally mobile individuals, as cross-border tax rules and regulatory differences can materially impact outcomes.

This is especially true when employment ends, residency changes, or a rollover is being considered.

This article outlines the fundamentals of effective high-net-worth individuals’ 401(k) management. It highlights the key considerations for internationally mobile investors, helping you maximise the long-term value of your retirement assets while taking account of tax, treaty, and planning issues that can arise outside the US.

Which Types of 401(k) Accounts Can You Select From?

From a tax perspective, 401(k) plans are generally divided into two categories:

• Traditional 401(k)
• Roth 401(k)

Traditional 401(k)

A traditional 401(k) account is funded with pre-tax contributions, which has two practical implications:

• Contributions reduce your current taxable income, while investment growth within the account is tax-deferred.
• Withdrawals in retirement are taxed as ordinary income.

When withdrawals are made, the entire amount, meaning both contributions and accumulated investment gains, is subject to income tax. Consequently, a traditional 401(k) is typically more advantageous if you expect to retire in a lower tax bracket or wish to reduce your current taxable income.

Traditional 401(k) contribution limits are reviewed annually and adjusted for inflation. For the 2026 tax year, the amount you can contribute is capped at $24,500 in employee elective deferrals.

Additional contribution allowances include:

Roth 401(k)

A Roth 401(k) reverses the taxation model of the traditional account. Contributions are made with after-tax income, but qualified withdrawals are free from US federal income tax.

According to the IRS, withdrawals are considered qualified if two conditions are met:

1. You are at least 59½ years old.
2. The account has been held for a minimum of five years before the withdrawal is made.

The contribution limits are the same as for traditional accounts. You may divide contributions between the two account types, but the combined total of your employee deferrals cannot exceed the annual cap of $24,500.

A key advantage of Roth 401(k) accounts is their flexibility in retirement. Unlike traditional accounts, they are not subject to required minimum distributions during the original account owner’s lifetime, allowing for more efficient long-term tax and estate planning. After the owner’s death, beneficiary distribution rules still apply.

What Happens to a 401(k) After Employment Ends?

The method by which you will manage your 401(k) after leaving an employer depends on your circumstances and future plans.

If you remain in the US and move to a new American employer, you may choose to roll over your existing 401(k) balance to your new employer’s plan. There are two approaches to doing so:

• Direct rollover: Funds are transferred directly from the old plan to the new one. This is typically the most efficient approach, as it avoids administrative complexity and unintended tax consequences.
• Indirect rollover: Funds are first distributed to you, and you must redeposit them into the new account within 60 days. Your former plan is generally required to withhold 20% of the amount for tax purposes, which can create liquidity constraints and potential tax exposure if not managed carefully.

You may also decide to leave funds in your former employer’s 401(k) plan. This approach may be sensible, particularly if the plan offers strong investment options or low fees. Whether the account can remain in place depends on the terms of the specific plan, and smaller balances may in some cases be distributed or transferred if no election is made.

Another commonly preferred option, especially among HNW expats, is to roll over your 401(k) into an individual retirement account (IRA). This approach offers several advantages:

• Access to a broader range of investment opportunities.
• The ability to consolidate multiple retirement accounts into a single structure.
• Greater control over withdrawal timing.
• Potentially simpler long-term management, depending on your country of residence and the receiving provider’s willingness to service non-US residents.

Finally, if you are already approaching retirement, you may consider taking distributions from your 401(k) upon ceasing employment.

Withdrawals can generally be made without penalties after reaching 59½, although they remain subject to income tax.

An important exception applies if you leave an employer at age 55 or older. In this case, you may take penalty-free withdrawals from that specific employer’s 401(k) plan, but they will still be taxed at your marginal income tax rate.

Which Rollover Pathways Are Generally Permitted?

Once employment ends, the next question is not simply whether to roll over your 401(k), but which assets can be rolled where. This matters particularly for HNW expats, as a technically valid rollover can still produce an inefficient cross-border result.

A 401(k) may contain more than one tax bucket, and those buckets should be identified before any rollover instruction is signed.

For expats, this review is particularly important because the most efficient US rollover route is not always the most effective cross-border solution.

Which Factors Impact the Outcome of 401(k) Accounts?

Beyond contribution levels, the long-term value of your 401(k) is primarily influenced by three key factors:

• Investment selection.
• Fees.
• Custody considerations.

Investment Selection

The asset classes your account invests in and the degree of diversification across them directly impact the long-term growth of your 401(k) balance. However, many conventional plans offer a relatively standardised mix of money-market funds, core bond funds, and equity index funds.

While such asset selection is designed to meet the needs of most 401(k) participants, it can limit the ability of HNW investors to implement more sophisticated or customised asset allocation strategies.

If you require greater flexibility, rolling over to an IRA may be worth considering. However, for expats, broader investment access should be assessed alongside tax treatment, custody access, fees, and liquidity.

That said, diversification within a 401(k) is still achievable, and some plans offer strong low-cost investment menus that may compare favourably with an IRA in practice.

If you are unsure whether your plan is contributing to your long-term objectives, Titan Wealth International can help. Our financial advisers can analyse your plan to determine its suitability and provide personalised recommendations on potential alternatives.

Fees

401(k) fees have a far more significant impact on long-term retirement outcomes than many investors assume. It is therefore crucial to understand and evaluate all costs associated with your plan, including:

• Investment expense ratio fees.
• Administrative fees.
• Transactional or service-related fees, such as obtaining a loan.

Fees are not always transparent and may be embedded within fund expenses or disclosed under different categories. It is therefore critical to review your plan’s fee disclosures, annual statements, and summary plan description to understand its true cost structure.

Custody Considerations

Custody arrangements can influence certain aspects of your 401(k), including:

• Asset protection
• Administrative efficiency
• Available investment options

In most cases, custody is handled by large financial institutions responsible for safeguarding plan assets and facilitating transactions.

For HNW expats, the more practical question is often whether the plan recordkeeper or receiving custodian will continue to service the account once you are resident outside the United States.

This can affect your ability to open a receiving IRA, continue trading, or complete withholding and treaty documentation correctly.

How Are 401(k) Withdrawals Taxed for HNW Expats?

The US taxes the global income and gains of all its citizens, regardless of their current residency circumstances. As a result, you may face taxation on the same 401(k) withdrawals both in the US and your country of residence.

To mitigate or eliminate double taxation for its citizens, the US maintains double tax agreements with numerous countries. While these treaties typically assign taxing rights over pension income between jurisdictions, many of them contain a saving clause.

The saving clause preserves the US government’s right to tax its own citizens as if the treaty were not in force. As a result, even where a double tax agreement assigns taxing rights to another jurisdiction, US citizens may still be subject to US taxation on their 401(k) distributions, with double taxation typically mitigated through foreign tax credits.

For instance, while the US-UK treaty may allocate taxing rights over pension withdrawals based on the nature of the distribution, the saving clause can preserve US taxing rights over US citizens, even where the treaty would otherwise appear to point in another direction. At the same time, the UK may tax the distribution based on residency, with relief generally available to prevent double taxation.

Given the complexity and variability of cross-border tax treatment, it is critical to review and understand the applicable tax treaty between the US and your country of residence. In most cases, partnering with an expat-focused tax and financial adviser is highly recommended to ensure compliance and optimise tax outcomes.

Why Roth Assets Require Separate Cross-Border Analysis

A Roth 401(k) can be highly attractive from a US tax perspective, particularly where qualified withdrawals are available free of US federal income tax.

However, expats should not assume that this treatment will automatically be mirrored in their country of residence.

For internationally mobile HNW investors, the key question is not only whether the withdrawal is qualified under US rules, but also whether the country of residence recognises the account’s tax character in the same way.

How To Integrate a 401(k) Into Holistic HNW Planning

Integrating a 401(k) into a broader HNW financial plan requires careful coordination across tax, investment, and estate planning considerations. One of the most important factors is the sequencing of withdrawals across different account types.

A typical HNW portfolio often includes a combination of:

1. Taxable brokerage accounts.
2. Tax-deferred retirement accounts, such as a traditional 401(k).
3. Tax-free accounts, such as a Roth 401(k).

In many cases, withdrawals are structured to draw first from taxable accounts, then from tax-deferred accounts, and finally from tax-free assets. This approach can help maximise long-term tax efficiency by allowing tax-advantaged assets to continue compounding over time.

However, HNWIs, particularly expats, may require a more dynamic and opportunistic strategy.

For instance, you may take larger 401(k) distributions during years of lower total income, such as periods between employment or early retirement, to reduce the effective tax rate on withdrawals. In cross-border contexts, this may also create opportunities to benefit from favourable treaty provisions or lower tax rates in the country of residence.

You must also consider the currency in which your expenses will be denominated to prevent exchange rate fluctuations from eroding returns.

Finally, you should understand the implications of including your 401(k) account in your estate plan. The most important rules to consider are:

• Most non-spouse beneficiaries are required to distribute the entire inherited 401(k) balance within 10 years. Certain eligible designated beneficiaries may be subject to different timing rules.
• A surviving spouse may elect to treat the deceased spouse’s plan as their own.
• A beneficiary who is a nonresident alien for US tax purposes may be subject to US withholding on distributions unless treaty relief applies and is properly documented.

What Mistakes Should You Avoid When Managing Your 401(k) Account?

The most common and costly mistakes in 401(k) management include:

• Taking withdrawals too early: Unless a specific exception applies, premature withdrawals taken before age 59½ are generally subject to a 10% early withdrawal penalty, in addition to ordinary income tax.
• Losing access to the Rule of 55: If you separate from your employer aged 55 or older, you may be able to take penalty-free withdrawals from that employer-sponsored plan. However, this exception generally only applies to assets that remain within the employer plan, such as a 401(k) or 403(b).
• Rolling to an IRA too soon: Rolling a 401(k) to an IRA before age 59½ can eliminate access to the Rule of 55, which may result in unnecessary penalties if you need to draw on those assets earlier than expected.
• Assuming treaty treatment is straightforward: If you are an expat, do not assume that all double tax agreement provisions applicable to your country of residence are clear or settled. In some cases, such as under the US-UK treaty, the treatment can be highly interpretive and should be reviewed carefully.
• Overlooking reporting and documentation: Proper and timely reporting remains essential. However, a US 401(k) should not automatically be treated as a foreign account reporting item solely because you live abroad. The reporting position should instead be assessed by reference to the account’s location and the wider cross-border structure.