1099 B
How to read Form 1099-B, where each sale goes on Form 8949 and Schedule D, the 2026 capital gains rates, and a calculator for the tax on a sale.
1099 B gain and Form 8949 calculator (2026)
Key 1099 B boxes
- Box 1d proceeds and Box 1e cost or other basis: the gain or loss is 1d minus 1e.
- Box 1g wash sale loss disallowed: a loss you can't take now because you bought substantially identical shares within 30 days; it's added back here and to the new shares' basis.
- Box 2 short-term or long-term. Box 12 checked means the broker reported your basis to the IRS (a covered lot).
Which Form 8949 box?
Short-term covered lots go in Box A, short-term noncovered in Box B, long-term covered in Box D, long-term noncovered in Box E. Covered lots with no adjustments can go straight on Schedule D lines 1a and 8a.
2026 capital gains rates
Short-term gains are taxed as ordinary income. Long-term gains are taxed at 0% up to $49,450 of taxable income ($98,900 joint), 15% up to $545,500 ($613,700 joint) and 20% above (IRS Rev. Proc. 2025-32), plus the 3.8% net investment income tax for high earners. More scenarios: capital gains tax calculator.
Common questions
What is Box 1g on Form 1099-B?
The wash sale loss disallowed, which is added to the basis of the replacement shares.
What does Box 12 checked mean on a 1099-B?
Your broker reported the cost basis to the IRS (a covered security).
What are the 2026 long-term capital gains brackets?
0% to $49,450 ($98,900 joint), 15% to $545,500 ($613,700 joint), 20% above.
Sources
More paycheck and tax calculators: 1095 B · 1098 T · 1099 C
Related
General information, not financial, tax or legal advice. Check important numbers with the official source before acting on them.