Understanding the IRS 8949 Form and Addendum Files

Understanding the IRS 8949 Form and Addendum Files

What Is IRS Form 8949?

IRS Form 8949 — Sales and Other Dispositions of Capital Assets — is the tax form used to report every sale, trade, or other taxable disposition of a capital asset, including cryptocurrency. It is filed alongside Schedule D and feeds directly into the capital gains and losses reported on your federal income tax return (Form 1040).

For most cryptocurrency portfolios, there are far too many individual transactions to list on the form itself. Instead, the form is completed with summary totals and a note of "SEE ATTACHED," with the transaction detail provided as a separate supporting schedule — in NODE40's case, the accompanying CSV file.


What NODE40 Generates

When you export a Form 8949 report from NODE40 Balance, you receive three related files that work together:

File

Format

Purpose

File

Format

Purpose

Form 8949 cover form

PDF

The official IRS form with summary totals — what gets filed with the return

Transaction detail

CSV

The "SEE ATTACHED" schedule — imported into tax software to populate Form 8949

Gain Loss report

Excel (.xlsx)

Full lot-level detail for CPA review and reconciliation


Structure of the PDF

The Form 8949 PDF is two pages:

  • Page 1 — Part I: Short-Term Transactions — covers assets held 12 months or less

  • Page 2 — Part II: Long-Term Transactions — covers assets held more than 12 months

Each page follows the same layout, with a checkbox section at the top, a transaction table in the middle, and a totals row at the bottom.


The Checkbox: Which Box Does NODE40 Check?

At the top of each page, the taxpayer must check one box indicating how the transactions were reported to the IRS. NODE40 checks:

  • Box I (Part I — Short-Term): "Short-term digital asset transactions not reported to you on Form 1099-DA or Form 1099-B"

  • Box L (Part II — Long-Term): "Long-term digital asset transactions not reported to you on Form 1099-DA or Form 1099-B"

These boxes apply to digital asset transactions where the broker has not reported basis to the IRS — which is the standard situation for most on-chain and decentralized transactions, as well as many exchanges that have not yet fully implemented 1099-DA reporting. This is the appropriate box for the majority of cryptocurrency transactions.

Note for CPAs: If any of the client's transactions were reported on a 1099-B or 1099-DA by a broker, those transactions may need to be reported on a separate Form 8949 page with a different box checked (e.g., Box G or Box J for 1099-DA transactions where basis was reported). Review any 1099-DA or 1099-B forms received by the client alongside the NODE40 export.


The Transaction Table

Rather than listing thousands of individual transactions, NODE40 populates the transaction table with a single summary row referencing the attached detail schedule:

Column

Value

Column

Value

(a) Description of property

The asset type (e.g., "SOL", "DIGITAL CURRENCY") and term (e.g., "SHORT TERM")

(b) Date acquired

Blank or representative date — detail is in the attached CSV

(c) Date sold

Blank or representative date — detail is in the attached CSV

(d) Proceeds

Summary total of all proceeds for the term

(e) Cost or other basis

Summary total of all cost basis for the term

(f) Adjustment code

Left blank or noted where applicable

(g) Adjustment amount

Left blank unless adjustments apply

(h) Gain or (loss)

Net gain or loss: column (d) minus column (e)

The description field references "SEE ATTACHED" to direct the IRS and reviewer to the accompanying CSV, which contains the full transaction-by-transaction detail.


The Totals Row

The totals row at the bottom of each page summarizes the entire Part I or Part II activity. These totals flow directly to Schedule D:

  • Part I totals → Schedule D, Line 1b, 2, or 3 (depending on which box is checked)

  • Part II totals → Schedule D, Line 8b, 9, or 10 (depending on which box is checked)

For Box I (short-term, no 1099-DA): totals go to Schedule D, Line 3 For Box L (long-term, no 1099-DA): totals go to Schedule D, Line 10


How to Read the Summary Figures

The PDF displays four key figures for each part:

Field

Description

Field

Description

Proceeds (col d)

The total fair market value received from all dispositions in the period for that term

Cost or Other Basis (col e)

The total cost basis of all assets disposed of

Gain or (Loss) (col h)

Net result: Proceeds minus Cost. Shown in parentheses if a loss

Important note on proceeds: The proceeds figure in the PDF reflects the total value of all outbound activity processed through NODE40 for the period. The CSV detail file and the Excel Gain Loss tab are the authoritative sources for reviewing individual transactions and verifying that only taxable dispositions are included in your filing. Review these files with your CPA before submitting.


The CSV: Column Structure

The CSV is specifically formatted for direct import into tax preparation software — such as UltraTax, Drake, Lacerte, or ProSeries — to auto-populate Form 8949 without requiring manual entry of individual transactions. Its columns map directly to the columns on IRS Form 8949:

CSV Column

Form 8949 Column

Description

CSV Column

Form 8949 Column

Description

Description

(a)

Asset name and quantity (e.g., "1.5 SOL", "100 USDC")

Date Acquired

(b)

Date the asset was originally acquired

Date Sold

(c)

Date the asset was sold or disposed of

Proceeds

(d)

Fair market value received at the time of disposition

Cost Basis

(e)

Original cost basis of the asset disposed of

Adjustment Code

(f)

A letter code indicating special tax treatment, if applicable

Adjustment Amount

(g)

Dollar amount of any adjustment associated with the code in column (f)

Term

"SHORT" or "LONG" — indicates whether the holding period qualifies as short-term (≤ 12 months) or long-term (> 12 months)


The "W" Adjustment Code

Some rows in the CSV carry an adjustment code of "W" in column (f). This flag is applied by NODE40's automated wash sale detection engine and does not mean your data is wrong. See Wash Sale Treatment in NODE40 Balance for a full explanation of why this code appears and what your CPA should do with it.