topic RSU Sales - Supplemental Form or 1099B? in Get your taxes done using TurboTax

RSU Sales - Supplemental Form or 1099B?

tacopa — Fri, 13 Feb 2026 15:12:53 GMT

I need help in handling RSU sales which are all basically losses. There are DRIPs that contributed wash sales as well.

The brokerage tax document contains both 1099B and supplemental forms. However, the dates, qty, basis are different in 1099B versus supplemental. While supplemental shows all of them LT, there are 2 txns that appear in 1099B Short term txn basis reported to IRS.

The total basis match exactly between supplemental and all of 1099 txns.

When TurboTax auto downloaded the txn from the brokerage, it downloaded txns that are on supplemental form.

For example, 1099B ST has a txn 4.924 dated 4/10/25, while supplemental has 3 lots (0.352, 4.063, 0.509 all dated 3/6/21). TurboTax also shows only the 3 txns (0.352, 4.063, 0.509) and defaulted to Long term covered.

Another example: There is a RSU sale for 60 (3/4/21) is split in 1099B to 7.447 ST-reported with date 4/10/25, and 52.553 LT-not reported with date 3/12/21.

Turbotax also asked me to upload the PDF consolidated pdf, and it went and adjusted basis some of the RSU lots, asked me to verify.

Do I simply use what is in the supplemental or try to match the 1099B for ST/LT etc?

Appreciate advise on this please. Thanks.

Re: RSU Sales - Supplemental Form or 1099B?

DaveF1006 — Fri, 13 Feb 2026 22:28:14 GMT

No. Do NOT try to force TurboTax to match the 1099‑B line‑by‑line when the broker provides a supplemental. The supplemental is usually the correct version for tax reporting. Your transactions are reported correctly.

Re: RSU Sales - Supplemental Form or 1099B?

tacopa — Fri, 13 Feb 2026 22:41:02 GMT

What about "Long term or short term". What do I choose for each of the lots? The lots in suplemental are all 2021 dates, while the one in 1099B is ST- basis reported to IRS. Do I make just these lots match 1099-B for this?

Re: RSU Sales - Supplemental Form or 1099B?

tacopa — Mon, 16 Feb 2026 23:30:11 GMT

Wanted to see if any advice on my questions - ST/Lt as supplemental dates are LT. Thanks for the help.

Re: RSU Sales - Supplemental Form or 1099B?

Karis_F — Wed, 18 Feb 2026 17:25:18 GMT

Using the Supplemental information is advised when dealing with RSU sales. The Supplemental information contains the cost basis that you need to adjust for the sale, and usually that basis is not reported properly on the Form 1099-B.

Using the same logic, going with the Supplemental information purchase date makes sense. However, make sure that you are matching the Supplemental RSU sales with the sales listed on the Form 1099-B to ensure you are picking up the correct basis for each sale.