Statutory & Regulatory Citations
This guide is grounded directly in the following federal and state tax statutes, Treasury regulations, and revenue rulings:
- 26 U.S.C. § 1012 — Cost Basis of Property
- 26 C.F.R. § 1.6045-1(n) — Broker Reporting of Cost Basis for Equity Compensation
- IRS Instructions for Form 8949 — Adjustment Code B (Incorrect Basis Reported on 1099-B)
1. Why Brokerages Report $0 Cost Basis on RSU Form 1099-B
Every tax season, thousands of technology employees accidentally pay federal and state taxes twice on the exact same RSU grant—once as W-2 ordinary wage income (~35%–48% combined) and a second time as a short-term capital gain (~35%–48%)—simply because they imported their brokerage Form 1099-B directly into tax software without auditing Box 1e (Cost or Other Basis).
Why does this happen? Under IRS broker basis reporting regulations (26 C.F.R. § 1.6045-1(n)), brokers are prohibited from adding W-2 compensation income into the official IRS-reported Box 1e cost basis for certain noncovered or net-settled equity awards, or they report the amount you "paid" for the RSU grant ($0.00) rather than the fair market value already taxed on your Form W-2.
When you vest 100 shares at $200/share, $20,000 is automatically added to your Form W-2 Box 1 wages. That $20,000 is now your "tax-paid cost basis" ($200/share). If you immediately sell those shares at $202/share ($20,200 proceeds), your true taxable capital gain is only $200 ($2/share). However, if your Form 1099-B lists Box 1e Cost Basis as $0.00 (or leaves it blank), unadjusted tax software will calculate a $20,200 short-term capital gain, overstating your taxable income by $20,000.
2. Brokerage-Specific 1099-B Audit Checklist (Schwab, E*TRADE, Fidelity, Morgan Stanley)
Each corporate stock plan administrator formats RSU cost basis slightly differently on its annual tax statements:
- E*TRADE by Morgan Stanley (Apple, Nvidia, Meta/Legacy): E*TRADE routinely reports $0.00 (or omits basis as noncovered) on the official Form 1099-B for RSU sales, while providing a separate "Stock Plan Transactions Supplemental Information" table at the back of the PDF that lists "Ordinary Income Reported on W-2" and "Adjusted Cost Basis." You must manually substitute the Adjusted Cost Basis on Form 8949.
- Charles Schwab Equity Award Center (Google, Meta): Schwab provides an "Equity Award Center Tax Lot Supplement" alongside the 1099-B. Check column 1e on your 1099-B: if the transaction is listed under Part I with Box 12 (Basis Reported to IRS) unchecked—or shows $0 basis—use the "Adjusted Cost or Other Basis" from the supplemental schedule.
- Fidelity NetBenefits (Microsoft, Amazon): When Microsoft or Amazon uses net-share withholding at vest, no 1099-B is generated for the shares withheld for taxes. For shares you sell yourself after vest, consult Fidelity’s "Supplemental Information for Employees" page in your Tax Reporting Statement to verify whether W-2 ordinary income was already included in Box 1e.
| Form 8949 Column | Unadjusted 1099-B Import (WRONG) | Corrected Form 8949 Entry (RIGHT) |
|---|---|---|
| Column (d) — Proceeds (Sales Price) | $20,200 | $20,200 |
| Column (e) — Cost or Other Basis (from 1099-B) | $0 | $0 (or unadjusted 1099-B figure) |
| Column (f) — Adjustment Code | (Blank) | Code B (or Noncovered Basis Entry) |
| Column (g) — Amount of Adjustment | $0 | ($20,000) — W-2 Ordinary Income Basis |
| Column (h) — Net Gain or (Loss) | $20,200 (Double Taxed!) | $200 (True Capital Gain) |
3. Watch Out for IRC § 1091 Wash Sales Across Monthly & Quarterly RSU Vests
Under IRC § 1091, if you sell stock at a capital loss and acquire "substantially identical" stock within 30 calendar days before or after the sale, the capital loss is disallowed as a Wash Sale and added to the cost basis of the replacement shares.
Because companies like Google vest GSUs every single month (every ~30 days) and companies like Meta, Microsoft, Nvidia, and Amazon vest quarterly (while employees may also purchase shares via ESPP), selling a post-vest RSU lot at a slight loss within 30 days of another RSU vest can trigger an automatic Wash Sale adjustment (Code "W" on Form 1099-B).
Calculate Your Specific RSU Tax Gap
Want to run these numbers on your own grant? Use our RSU tax calculator to estimate your 2026 federal and state withholding gap, the $184,500 Social Security cap offset, and how many extra shares to sell at vest: