The answer is straightforward: if you hold RSUs (Restricted Stock Units) at Austin tech companies like Tesla, Apple, or Oracle, and you've already paid tax on them through your W-2 in the year they vested, the 1099-B you receive when you sell the shares will very likely report a cost basis of zero or some negligible token amount. If you copy the 1099-B figures directly onto Form 8949 without adjustment, that income — which has already been taxed once — gets counted again as a capital gain, meaning you pay tax on the same money twice. This is one of the most common, and most easily overlooked, mistakes during tax season for Chinese professionals in Austin.
If Tax Was Already Paid When the RSUs Vested, Why Does the 1099-B Still Show Tax Due?
The tax logic behind RSUs is actually not complicated: on the day the shares vest, their fair market value on that date is included in full as ordinary income on your W-2, and your employer withholds tax on it (typically through an automatic partial sale of shares known as "sell-to-cover"). This means the market price on the vest date becomes your cost basis in those shares, because you've already paid income tax on that value.
The problem originates on the broker's side. Most brokers (such as E*TRADE, Fidelity, and Schwab) record cost basis on the 1099-B based only on cash you actually paid out of pocket — but since RSUs are granted to you at no cost, the system often defaults to reporting a cost basis of zero, or a figure far below the actual market value at vesting. The result: if you report the 1099-B numbers as-is, the entire sale proceeds get taxed again as capital gains, even though that value was already taxed as ordinary income on your W-2 in the year of vesting. For employees with large vesting positions in highly volatile stocks like Tesla, this discrepancy can translate into thousands, or even tens of thousands, of dollars in extra tax.
Form 8949 Adjustment Code B: How to Correct the Error
The fix is to use adjustment Code B on Form 8949 to manually correct the understated cost basis. In practice: in Part I (short-term) or Part II (long-term) of Form 8949, depending on the holding period, first enter the original figures as reported on the 1099-B (Column e is the broker-reported cost basis), then enter Code B in Column f and the adjustment amount in Column g (usually a negative number, since you're adding back the understated basis); Column h will then automatically calculate the correct capital gain or loss.
The correct cost basis should equal the number of shares vested multiplied by the closing price on the vest date (i.e., the amount already included in your W-2), plus any cash you may have paid. You can obtain the exact share counts and market prices for each vesting event from your company's equity management platform (such as E*TRADE's Supplemental Information or a company-issued Vesting Confirmation) and reconcile them one by one. If you had multiple vesting events during the year and sold shares in separate lots, this reconciliation can be quite time-consuming — which is why many Chinese tech employees working in Austin choose to work with a professional Austin Chinese CPA to handle it, avoiding either an overpayment from a missed correction or an IRS inquiry triggered by an incorrect adjustment. If this is your first time dealing with equity compensation on your tax return, we recommend first reviewing our Chinese Tax Filing Guide to understand the overall filing process before working through the details.
ESPP Qualifying vs. Disqualifying Dispositions: How Big Is the Difference?
The tax treatment of an Employee Stock Purchase Plan (ESPP) is one layer more complex than RSUs, because it depends on whether the sale is a "Qualifying Disposition" or a "Disqualifying Disposition" — and this distinction directly determines whether the discount portion is treated as ordinary income or capital gain.
The test is based on holding period: you must hold the shares for at least 2 years from the Grant Date, and at least 1 year from the Purchase Date — both conditions must be met for the sale to qualify as a Qualifying Disposition. If both are met, the applicable portion of the discount received at purchase can be treated as a capital gain, taxed at the lower rate. If you sell before meeting both holding periods, it's a Disqualifying Disposition, and the discount portion must be reported as ordinary income (usually reflected on that year's or the following year's W-2, or which you must report yourself as other income), with the remaining appreciation taxed as a capital gain. Many people focus only on "how much I made when I sold" and overlook the need to properly characterize the ESPP discount income, resulting in either mistakenly treating income that should be ordinary as entirely capital gain, or conversely failing to report the ordinary income portion. This same issue affects the accuracy of the cost basis on your 1099-B, because whether the discount has already been included in your taxable income directly determines what the correct cost basis should be.
ISO Exercises: Don't Overlook the AMT Trap
The tax treatment of Incentive Stock Options (ISOs) differs again from both RSUs and ESPPs. The spread at exercise (the difference between the exercise price and the market price on that day) is not included in your regular taxable income and does not need to appear on your W-2 — this is one of the appeals of ISOs relative to Non-Qualified Stock Options (NSOs). But that doesn't mean exercising an ISO has no tax consequences at all — this spread must be included in the income base for the Alternative Minimum Tax (AMT), calculated on Form 6251.
For employees holding a large number of ISOs who plan to hold the shares long-term to qualify for more favorable capital gains tax rates, the year of exercise can very well produce an unexpected additional tax liability due to AMT — even if you haven't actually sold any shares or received any cash. We raise this only as a general caution, because whether AMT is triggered, and by how much, depends on your overall income structure for the year, other deductions, and credits (such as any carryforward of the AMT Credit). We do not recommend making an exercise decision based on a rough, self-calculated estimate.
YZ CPA Note
Errors in reporting equity compensation usually don't stem from a lack of tax knowledge, but from the fact that the relevant information is scattered across your W-2, 1099-B, and your company's equity platform — it's easy to miss a reconciliation, adjust incorrectly, or skip the check entirely. We recommend that Chinese taxpayers in Austin, before filing, compile a single table listing the date, number of shares, and market price for every vesting event, every ESPP purchase, and every ISO exercise, and check each entry against the cost basis reported on the 1099-B to confirm it matches the amount already included on the W-2 — this is especially important if you've switched brokers or had multiple transactions in a single year, as gaps in the record are more likely to occur. If your employer offers two or more of RSUs, ESPP, and ISOs, we recommend working with a professional for comprehensive planning that addresses your equity income, AMT exposure, and whether you need to report foreign assets (such as an overseas brokerage account — see our FBAR Filing Guide) together as a whole. More frequently asked questions are also available in our Tax Insights section.
For professional tax assistance, please visit the YZ CPA Services page or Contact Us.