How RSUs Fit Into Your Retirement Plan

Picture this: you've worked hard, your company's equity compensation package looked great on paper when you joined, and now shares are hitting your account on vesting day. It feels like a bonus, and in many ways it is. But restricted stock units, commonly called RSUs, come with a set of financial planning considerations that can catch even experienced professionals off guard.

The tax treatment alone is more complex than most people realize. Layer on top of that the question of whether to hold or sell, and the quiet but significant risk of having both your paycheck and your investment account tied to the performance of one company, and it becomes clear that RSUs deserve a dedicated place in your retirement planning conversations. This article explores the key concepts, without telling you what to do, so you can have more informed discussions with the professionals who can.

One of the most common misconceptions about RSUs is that tax is only triggered when you sell the shares. In reality, the IRS treats RSUs differently from stock options. When your RSUs vest, the fair market value of the shares on that day is included in your ordinary income for the year, reported on your W-2 alongside your salary. You owe income tax on that amount whether you sell the shares immediately or hold them for years.

This has a few important implications:

• Your tax bracket may jump. A large vest in a single tax year can push you into a higher federal income tax bracket, sometimes significantly so. The 2024 federal income tax brackets reach 37% for taxable income above $609,350 for single filers and $731,200 for married filing jointly (IRS Revenue Procedure 2023-34).
• State income taxes apply too. Most states with an income tax treat RSU income the same way the federal government does, adding another layer to the tax calculation.
• FICA taxes may apply. Social Security and Medicare taxes (FICA) generally apply to RSU income in the year of vesting, up to the applicable wage base limits.

After the vest date, any additional gain or loss on the shares is treated as a capital gain or loss. If you hold the shares for more than one year after vesting, that gain may qualify for long-term capital gains rates, which are generally more favorable than ordinary income rates. If you sell within a year of the vest date, the gain is taxed at short-term capital gains rates, which are the same as your ordinary income rate.

When RSUs vest, your employer is required to withhold income taxes, much like they do on your regular paycheck. The IRS allows employers to use a flat supplemental wage withholding rate for this purpose. As of 2024, that flat rate is 22% for supplemental wages up to $1 million, and 37% for amounts above that threshold in a single year (IRS Publication 15).

Here's where the problem emerges: if your total income, including salary, bonuses, and RSU vesting income, places you in the 32% or 35% federal tax bracket, a 22% withholding rate on your RSUs will leave a meaningful gap. That gap becomes money owed to the IRS at filing time, and if the underpayment is large enough, it can trigger an underpayment penalty.

Consider a hypothetical example for illustration purposes only. Imagine a software engineer with a $180,000 salary who receives $80,000 worth of RSUs vesting in a single calendar year. Their combined income of $260,000 places them well into the 32% federal bracket. If their employer withholds at the default 22% supplemental rate on the RSU income, roughly $17,600 is withheld. But the actual federal tax owed on that income at their marginal rate could be closer to $25,600, leaving a gap of approximately $8,000 before state taxes are even considered. This is a simplified illustration and individual results will vary based on deductions, filing status, and other factors.

Some approaches employees and their advisers consider to address this gap include:

• Adjusting W-4 withholding to account for expected RSU income during the year.
• Making estimated quarterly tax payments to the IRS using Form 1040-ES.
• Working with a tax professional ahead of known vesting dates to model the full-year tax picture.

Keeping track of your total compensation, including expected vest dates and share values, as part of your broader year-end tax planning can help prevent unwelcome surprises come April.

Beyond the tax mechanics, there's a retirement planning dimension to RSUs that deserves careful attention: concentration risk. When a meaningful portion of your compensation comes as shares in your employer, you are effectively doubling down on one company's fortunes. Your salary depends on the business, and so does a growing portion of your investment portfolio.

This matters because the two risks are correlated in ways that can be painful during downturns. If a company hits hard times, layoffs often come alongside a decline in the stock price. Employees may find themselves facing job loss and a significant drop in the value of their equity holdings at the same time. Diversification, a foundational concept in long-term investing, is specifically designed to reduce this kind of correlated risk by spreading exposure across different assets and sectors.

The challenge is that many employees feel a strong attachment to their employer's stock, either out of loyalty, optimism about the company's future, or a hope that the shares will continue to appreciate. These feelings are understandable, but they are worth examining honestly as part of a broader retirement plan. Even companies with strong track records can face unexpected disruptions.

Understanding how this risk interacts with the rest of your financial picture, including your 401(k), IRA, and other savings, is an important part of thinking about tax and asset diversification across your retirement accounts.

One approach that financial planners often discuss in the context of RSU management is sometimes called a systematic sell-at-vest strategy. The basic concept is straightforward: when RSUs vest, some employees and their advisers choose to sell the shares promptly and deploy the after-tax proceeds into a more diversified portfolio, rather than accumulating a growing position in the employer's stock.

The logic behind this approach rests on a few observations:

• The tax cost of selling at vest is often modest. Because the share value at vesting is already taxed as ordinary income, there is typically little or no additional capital gain to recognize if you sell immediately at or near the vest price. This can make the vest date a relatively tax-efficient moment to reallocate.
• It creates a systematic habit. Rather than making hold-or-sell decisions based on market sentiment or emotion, a consistent approach removes some of the behavioral friction from the process.
• Proceeds can be redirected. Cash from RSU sales can be directed toward retirement savings vehicles. Depending on income limits and account types, this might include contributing to a Roth IRA, adding to a taxable brokerage account, or funding other savings goals. For higher earners who have already maxed out tax-advantaged accounts, understanding where to invest after maxing out your 401(k) becomes especially relevant.

It is worth noting that a sell-at-vest approach is not universally appropriate. Factors that vary significantly between individuals include: the size of the existing concentration relative to total net worth, personal tax situation, other sources of retirement income, and views on the company's future prospects. This is precisely why the conversation is best held with a qualified financial adviser who can assess the full picture.

For those who hold a large existing block of company stock that has appreciated significantly above its vest-date cost basis, the tax equation becomes more complex. Selling highly appreciated shares triggers capital gains, which requires a different analysis than selling at vest. A tax professional can help model the trade-offs between the tax cost of diversifying and the ongoing risk of holding a concentrated position.

RSUs don't exist in isolation. They are one piece of a larger retirement planning picture that typically includes a 401(k), potentially an IRA, taxable savings, and eventually Social Security. Thinking about how RSU income and equity holdings interact with each of these elements is useful groundwork.

A few areas worth exploring with a qualified adviser include:

• Retirement account contributions in high-income years. A large vest can push income higher, which may affect eligibility for certain accounts like a direct Roth IRA contribution (which phases out at higher income levels). It may also create an opportunity to explore strategies like a backdoor Roth conversion.
• Estate planning considerations. A growing concentration of employer stock can become a meaningful estate asset over time, with implications for beneficiary designations and potential step-up in cost basis at death. These are areas where an estate planning attorney can provide guidance.
• Timing vesting events relative to other income. Some employees have limited ability to influence when RSUs vest, but others may have some flexibility in compensation arrangements that a financial planner can help evaluate.
• Medicare premium surcharges. Higher income years, including those with significant RSU vesting, can affect income-related Medicare premium adjustments (IRMAA) in subsequent years for those approaching or in retirement. This is worth modeling in advance.

The broader point is that RSU management is not just an investment question. It is a tax question, a risk management question, and a retirement income question all at once. That's why it benefits from coordinated advice across financial planning, tax, and sometimes legal disciplines.

If you are still in the accumulation phase and weighing how equity compensation fits alongside your other savings, it may also be worth revisiting how much of your income is going toward retirement overall. A sense of what savings rate might support your goals is foundational context for any conversation about RSU strategy. Resources on what percentage of income to save for retirement can provide useful framing.