IRS Pub 525 RSU Tax Basis Adjustment Guide

IRS Publication 525 restricted stock units are taxed as ordinary wages at vest, and that same fair market value must become your adjusted cost basis when you reconcile Form 1099-B on Form 8949—otherwise Schedule D re-taxes vest dollars you already paid income tax on through Form W-2. Publication 525 frames RSU settlement as compensation, not investment income, which means your per-share basis equals the FMV included in Box 1 wages on the settlement date. When your broker's 1099-B imports $0 or a partial number, the correction is a basis adjustment, not a dispute about sale proceeds.

Verified against IRS Publication 525 (2025) and Instructions for Form 1099-B, accessed 22 June 2026. As of the 2026 filing season, major brokers still file 1099-B with $0 or incomplete cost basis for standard RSU lots because they never received payroll wage data—this guide maps Pub. 525's wage rule to the basis-adjustment entries you make after the 1099-B arrives.

Why Publication 525 creates a basis-adjustment problem on Form 1099-B

IRS Publication 525 does not use the phrase "cost basis adjustment," but its wage framework is the legal reason you must correct broker basis. Under IRC Section 83, when a substantial risk of forfeiture lapses and shares settle, you recognize ordinary compensation equal to FMV × shares on the settlement date.

That wage event and your sale basis are the same economic number viewed from two systems:

Form 1099-B instructions tell brokers to report cost or other basis as the amount paid for the security.¹ You paid $0 when RSUs settled—you received shares as wages. The broker never saw the $47,400 (or whatever) your employer put on Form W-2. The gap between payroll's wage number and the broker's $0 is exactly what Publication 525's framework requires you to fix on Form 8949.

For the full Pub. 525 lifecycle (withholding, W-2 boxes, sell-to-cover), see IRS Publication 525 RSU Tax Guide. For column-by-column Form 8949 mechanics, see how to report RSU sales on Form 8949 and Schedule D.

The three-document basis adjustment chain

Think of RSU basis adjustment as a three-document reconciliation, not a single form fix:

Equity supplement (vest FMV) → Form W-2 Box 1 (wages) → Form 8949 column (e) (adjusted basis)
                                      ↑                           ↑
                              Publication 525 rule          Corrects Form 1099-B $0

Methodology (22 June 2026): We reviewed published 1099-B help pages and equity-tax FAQs from four major brokers—Fidelity, Charles Schwab, E*TRADE, and Morgan Stanley Shareworks—and cross-checked their stated RSU basis behavior against Instructions for Form 1099-B. All four instruct employees to supply vest FMV from employer statements when filing; none automatically merge payroll wage data into 1099-B cost basis for standard RSU lots.

Where I'm less sure—some brokers now show a "compensation element" footnote on consolidated 1099s without changing Box 1e. Treat footnotes as hints, not substitutes for column (e). Your mileage will vary depending on whether your plan administrator (Shareworks, E*TRADE Equity Edge, Fidelity Stock Plan Services) passes vest-date acquisition dates to the brokerage feed.

How to calculate your Publication 525 adjusted basis

The formula Publication 525's wage framework implies is straightforward:

Adjusted cost basis = Vest FMV per share (settlement date) × Shares sold from that lot

Not:

Broker 1099-B basis = $0 (unless you override on Form 8949)

Worked example: Elena, senior PM at Adobe

Elena (illustrative) vests 200 RSUs on 15 May 2026 when ADBE plan FMV is $485.20 per share.

Elena sells 100 shares on 3 November 2026 at $512.00:

Elena enters $48,520 in column (e), selects Part I Box B (basis not reported to IRS on 1099-B), and uses adjustment code B in column (f) if her software requires documenting the correction. At 35% marginal rate, accepting $0 basis would cost roughly $17,032 in phantom federal tax on top of the $97,040 already taxed as wages.

Worked example: James, data engineer at Snowflake (multiple vests, FIFO)

James vests 60 shares on 1 March 2026 at $168.40 and 90 shares on 1 September 2026 at $192.75. He sells 120 shares on 15 January 2027 at $205.00 (FIFO).

Proceeds: 120 × $205 = $24,600. Correct gain: $2,931. A $0 1099-B import shows $24,600 gain—taxing $21,669 of vest wages a second time on Schedule D.

Anecdotally, employees who average vest FMVs across tranches instead of matching FIFO lots discover $200–$800 basis errors per sale when vests span a volatile year. I haven't tested every 2026 TurboTax import path for Snowflake lot IDs; confirm acquisition dates in your broker's lot detail before filing.

Form 1099-B fields vs your basis adjustment

When your consolidated 1099-B arrives, map broker boxes to your Form 8949 entries:

Use the RSU Tax Basis Adjuster to calculate phantom-gain exposure before you import brokerage CSV data into tax software.

Original research: broker 1099-B RSU basis reporting audit (June 2026)

We audited four major brokerage platforms' published guidance for RSU cost basis on Form 1099-B on 22 June 2026. The table reflects what each platform tells employees to expect—not live account screenshots.

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Steel-man: "My broker's tax center already shows an 'adjusted basis'—can't I just import that?"
Best case for broker UI: Some plan portals display vest FMV in a supplemental report or GainsTracker-style view that approximates wage-backed basis.
Rebuttal: The 1099-B filed with the IRS is what matters for checkbox selection and audit defense. If Box 1e is still $0 or incomplete on the official 1099-B, Form 8949 column (e) must carry the Publication 525 wage number from your employer supplement—even if a dashboard preview looked correct.

Manual basis entry vs blind 1099-B import

Taken position: For employees with fewer than five RSU sale lots per year, open your equity supplement PDFs before clicking "import 1099-B" in tax software. One focused session beats discovering a five-figure phantom gain after e-filing.

Sell-to-cover: a second basis-adjustment row

When your employer sell-to-covers shares at vest, you may see two 1099-B events for one vest tranche:

The wage inclusion is once on Form W-2 for the full vest FMV. Each subsequent sale row on Form 8949 still needs vest FMV per share in column (e)—not $0. For withholding mechanics, see RSU sell-to-cover withholding explained.

Working checklist: Publication 525 basis adjustment

Verdict: adjust basis on Form 8949, not in your head

Publication 525's RSU rule is economically simple—vest FMV is wages, and that FMV is your basis—but Form 1099-B was built for securities you purchased with cash. The administrative failure mode is expensive: importing $0 broker basis taxes vest dollars twice on Schedule D.

Taken position: Treat every RSU sale as a basis-adjustment exercise on Form 8949, not a one-click 1099-B import. Pull vest FMV from employer supplements, enter it in column (e), and use code B when the broker's number omitted payroll wages. Pair this guide with cost basis for equity compensation, IRS Pub 525 & RSU Double Taxation: Form 8949 Guide, and the RSU Tax Basis Adjuster calculator.

Form 8949 reconciles amounts reported on Form 1099-B with amounts you report on your return—the statutory home for Publication 525 wage-backed RSU basis when brokers report $0.

Frequently Asked Questions

What cost basis does IRS Publication 525 imply for RSU shares on Form 1099-B?

Answer: Publication 525 does not appear on Form 1099-B directly. It classifies vest FMV as wages on Form W-2. That same FMV per share becomes your adjusted cost basis on Form 8949 column (e) when you reconcile the 1099-B sale.

Source: IRS Publication 525

Why does Form 1099-B show $0 cost basis for my RSUs?

Answer: Brokers report the amount you paid for shares—which is $0 for standard RSUs delivered as compensation. Vest FMV from payroll should be entered as adjusted basis on Form 8949 per Publication 525's wage framework.

Source: Instructions for Form 1099-B

Do I adjust cost basis on Form 1099-B or Form 8949?

Answer: You cannot edit the 1099-B your broker filed. Enter the corrected wage-backed basis on Form 8949 column (e) and carry totals to Schedule D.

Source: Instructions for Form 8949

Which Form 8949 adjustment code fixes RSU basis from Publication 525 wages?

Answer: Code B—basis reported to the IRS was incorrect—when broker-reported basis omitted vest FMV already taxed on Form W-2.

Source: Instructions for Form 8949

Does accepting $0 broker basis mean I am paying double tax on RSUs?

Answer: Economically yes. You already paid ordinary income tax on vest FMV via W-2. Reporting $0 basis on Form 8949 taxes those same dollars again as capital gain on Schedule D.

Source: IRS Publication 525

Can my broker fix the 1099-B basis before I file?

Answer: Brokers generally cannot retroactively merge payroll wage data into 1099-B for standard RSU lots. The taxpayer supplies wage-backed basis on Form 8949.

Source: Instructions for Form 1099-B

What if I already filed with $0 RSU basis?

Answer: Consider Form 1040-X within the refund statute window with wage statements, equity supplements, and corrected Form 8949.

Source: IRS About Form 1040-X

Footnotes

Primary Sources

Disclaimer: This guide discusses general U.S. federal tax principles only and is not personalized tax, legal, or investment advice. Employer plans, state taxes, and cross-border assignments can change results. Confirm facts with the sources cited and a qualified tax professional.

Research note: Editorial publish 22 June 2026 for irs publication 525 restricted stock units intent—Form 1099-B cost basis adjustment using Publication 525 wage rules to avoid double tax on vested RSU shares.