How to Fill Out Form 8949 for Crypto: Step-by-Step Guide

What Is Form 8949?

Form 8949 ("Sales and Other Dispositions of Capital Assets") is where every crypto sale, trade, and disposal is individually reported to the IRS. Every taxable crypto transaction flows through Form 8949 to Schedule D, which then flows to your Form 1040.

Form 8949 is not new — it's the same form used for stocks, bonds, and real estate sales. What's new is the volume: crypto traders often have thousands of transactions that need to appear here. For most people using crypto tax software, Form 8949 is generated automatically. But understanding the form helps you verify accuracy and catch errors.

The Two Parts: Short-Term vs Long-Term

Form 8949 has two identical sections:

• Part I: Short-term transactions (assets held 12 months or less). Gains taxed at ordinary income rates (10–37%).
• Part II: Long-term transactions (assets held more than 12 months). Gains taxed at preferential rates (0%, 15%, 20%).

Sorting your transactions correctly between Part I and Part II is critical — an error here results in incorrect tax rates being applied. The holding period runs from the day after acquisition to the date of disposal.

The Column-by-Column Walkthrough

Column (a): Description of Property

Enter a brief description of what you sold: "0.5 BTC", "100 ETH", "1,000 MATIC". You don't need to include the exchange name here, though it's helpful.

Column (b): Date Acquired

The date you originally bought or received the specific lot being sold. This determines your holding period. For mining income, the "acquisition date" is the date the coins were mined. For staking rewards, it's the date the rewards were received.

Column (c): Date Sold or Disposed Of

The date of the disposal — when you sold, traded, spent, or otherwise disposed of the asset.

Column (d): Proceeds

The fair market value of what you received. For a BTC → USD sale, this is the USD amount. For a BTC → ETH trade, this is the USD value of the ETH received at the time of the swap. Do not subtract fees here — fees go in column (e) as an adjustment.

Column (e): Cost or Other Basis

What you originally paid for the asset, including acquisition fees. For mined coins, this is the FMV on the date mined (the amount you included in income). For gifted crypto, cost basis rules are complex — see our gift tax guide.

Column (f): Adjustment Code

This is where many people make mistakes. The most common codes for crypto:

• B: Basis reported to IRS is incorrect (e.g., exchange reported wrong cost basis on 1099-DA)
• E: Excluded from gross income under a specific provision (rare for crypto)
• H: Ordinary loss from Section 1244 stock (not applicable to crypto)
• W: Wash sale loss disallowed — generally does not apply to crypto in 2026, but would apply to Bitcoin ETF shares

If no adjustment is needed and the broker-reported basis is correct, leave column (f) blank and skip column (g).

Column (g): Adjustment to Gain or Loss

If you entered a code in column (f), enter the dollar amount of the adjustment here. For example, if the exchange over-reported your proceeds by $500 (code B), enter -$500 in column (g).

Column (h): Gain or Loss

Column (d) minus column (e) plus or minus column (g). This is your final gain (positive) or loss (negative) for the transaction.

The Check Box at the Top

Each Part of Form 8949 has a checkbox at the top asking how the transactions were reported to the IRS:

• Box A (short-term) / Box D (long-term): Reported on Form 1099-B (or 1099-DA) with basis reported to IRS
• Box B (short-term) / Box E (long-term): Reported on 1099-B/DA without basis reported
• Box C (short-term) / Box F (long-term): Not reported on 1099-B/DA (e.g., DEX trades, P2P transactions, off-exchange)

For most crypto users in 2026: centralized exchange trades go in Box A/D (with 1099-DA), while DEX trades and wallet-to-wallet transactions go in Box C/F. If you use multiple exchanges and wallets, you'll likely have multiple copies of Form 8949 with different boxes checked.

Schedule D: The Summary

Form 8949 is the detail. Schedule D is the summary. The totals from each section of Form 8949 (Part I short-term, Part II long-term) flow into the corresponding lines of Schedule D. Schedule D also includes any capital loss carryovers from prior years.

The net capital gain or loss from Schedule D flows to Line 7 of Form 1040. If you have a net capital loss, it offsets up to $3,000 of ordinary income per year; any excess is carried forward.

Common Mistakes to Avoid

• Wrong holding period: Placing a long-term gain in Part I (short-term) causes you to pay the higher ordinary income rate unnecessarily
• Missing DEX trades: Not all exchanges issue 1099s for DeFi activity — you're still required to report it yourself on Form 8949, Box C/F
• Double-counting exchange 1099-DA: If you import a 1099-DA and your crypto tax software also pulled the same trades from the exchange API, you'll double-count every transaction
• Wrong cost basis for mined/staked coins: The cost basis is the FMV on the date received (the income amount), not $0
• Ignoring small transactions: Every swap, including tiny fee refunds and dust amounts, is reportable. The IRS has no de minimis threshold for crypto

Using Software vs. Filing Manually

For most crypto users with more than a handful of transactions, manually filling Form 8949 is not realistic. Blockchain Smart Tax generates a complete, IRS-ready Form 8949 and Schedule D automatically, with transactions correctly sorted between short-term and long-term, cost basis methods applied per wallet, and adjustment codes inserted where needed.

Generate Form 8949 Automatically

Blockchain Smart Tax generates Form 8949, Schedule D, and international tax reports automatically from your on-chain data. Connect your wallets, review the classified transactions, and download your completed forms — no manual spreadsheets required.

How we compare to other crypto tax platforms:

• Koinly ($49+/year) — popular choice with solid tax form generation and broad exchange support
• CoinTracker ($59+/year) — direct TurboTax integration with polished reporting interface
• CoinLedger ($49+/year) — solid form generation with good NFT support
• Blockchain Smart Tax (from $25/year) — automatic form generation, wallet discovery across 550+ chains, all cost basis methods free, free during beta

Import your wallets and generate your tax forms — free during beta →

Related Articles

• How Crypto Is Taxed in 2026: Complete IRS Guide
• FIFO vs LIFO vs HIFO: Which Cost Basis Method Saves You Money?
• IRS Crypto Audit: What to Expect and How to Prepare