Crypto Cost Basis Methods: FIFO vs Specific ID vs HIFO

“The cost basis method you choose can swing your crypto tax bill by thousands of dollars, and starting in 2025, the IRS locked you into per-wallet accounting. Choose wisely.”

, Reviewed by Leanne Grant, EA

Quick answer: Your crypto cost basis is what you originally paid for a coin (including fees). When you sell, you subtract the cost basis from the sale price to calculate your gain or loss. The method you use, FIFO, LIFO, HIFO, or Specific Identification, determines which coins are treated as sold first. FIFO is the default. Specific Identification with HIFO ordering typically produces the lowest tax bill. But after Rev. Proc. 2024-28, you need to track basis per wallet, and you need proper records to back up any method besides FIFO.

What Is Cost Basis in Crypto?

Cost basis is the original value of a crypto asset for tax purposes. It includes the purchase price plus any transaction fees you paid to acquire it.

When you sell, swap, or spend crypto, the IRS requires you to calculate the difference between your sale proceeds and your cost basis. That difference is your capital gain (or loss).

Here's the problem: most crypto investors don't buy all their coins at once. You might buy Bitcoin at $30,000 in January, $45,000 in June, and $38,000 in November. When you sell some of that Bitcoin, which purchase price counts as your basis?

That's what cost basis methods solve. They're the rules for matching your sales to your purchases.

This isn't optional. Form 8949 requires you to report the cost basis for every single crypto disposal. Get it wrong, and you're looking at penalties, interest, or an audit.

If you're new to crypto taxes generally, start with our complete crypto tax guide for 2026, it covers the fundamentals before you dive into cost basis specifics.

FIFO (First In, First Out), The Default

FIFO means the coins you bought first are treated as the coins you sold first.

How it works: Your purchases are lined up chronologically. When you sell, the IRS assumes you're disposing of your oldest coins.

Why it matters: In a rising market (which crypto has been for most of its history), your oldest coins have the lowest cost basis. That means FIFO typically produces the highest taxable gain.

IRS status: FIFO is the default method under Rev. Proc. 2024-28. If you don't actively choose and document a different method, you're on FIFO automatically.

The upside of FIFO:

• Zero record-keeping burden beyond basic transaction history
• No risk of IRS challenge on method selection
• More of your gains qualify as long-term (held over 1 year) since you're selling oldest lots first

The downside:

• In bull markets, you pay the most tax
• You have no flexibility to optimize

Best for: Investors who want simplicity, those with mostly long-term holdings, or anyone who hasn't kept detailed records.

LIFO (Last In, First Out), Not Recommended for Crypto

LIFO means your most recently purchased coins are treated as sold first.

How it works: The opposite of FIFO. Your newest purchases get matched to your sales.

Why it's problematic for crypto: LIFO is accepted for inventory accounting in certain business contexts, but the IRS has never explicitly approved LIFO for capital asset dispositions like crypto sales. Notice 2014-21 treats crypto as property, not inventory.

The bigger issue: LIFO tends to produce short-term gains (taxed at ordinary income rates up to 37%) because you're always selling your newest coins. That's usually worse than FIFO from a pure tax perspective.

Best for: Almost nobody. If you want to sell recent lots, use Specific Identification instead, you get the same result with actual IRS backing.

HIFO (Highest In, First Out), The Tax Minimizer

HIFO means the coins with the highest cost basis are treated as sold first, regardless of when you bought them.

How it works: Every time you sell, the lot with the highest per-unit cost gets depleted first. This maximizes your cost basis and minimizes your taxable gain.

IRS status, and this is important: The IRS has not explicitly endorsed HIFO as a standalone method. HIFO is widely used and accepted by crypto tax software, but technically it functions as a subset of Specific Identification. You're specifically identifying the highest-cost lots for each sale.

This means HIFO carries the same record-keeping requirements as Specific ID (more on that below). You can't just claim HIFO retroactively without documentation.

The upside:

• Produces the lowest possible taxable gain (or largest loss)
• Widely supported by crypto tax platforms
• Defensible as Specific ID if you have records

The downside:

• Requires lot-level tracking and contemporaneous documentation
• May produce more short-term gains (highest-cost lots are often recent purchases)
• No explicit IRS guidance endorsing the label "HIFO"

Best for: Active traders and high-net-worth investors who maintain detailed records and want to minimize current-year taxes. This is what many crypto tax CPAs, including our team, implement for clients.

Specific Identification, Maximum Control

Specific Identification means you choose exactly which lot to sell for each transaction.

How it works: At the time of each sale, you designate which specific coins you're disposing of. You might sell Lot 3 from August because it gives you a long-term loss, even though Lots 1 and 2 are older.

IRS requirements for Specific ID in crypto: Under Rev. Proc. 2024-28 and general IRS guidance, you need:

1. Contemporaneous identification, You must identify the specific lot at the time of the sale (or within a reasonable time), not retroactively at tax time
2. Adequate records, Transaction IDs, timestamps, wallet addresses, and lot details
3. Per-wallet/per-account tracking, As of January 1, 2025, you must track lots separately for each wallet and exchange account

Why this is the gold standard: Specific ID gives you complete flexibility. You can pick the lot that produces the best tax outcome for each individual transaction:

• Sell high-basis lots to minimize gains
• Sell lots held over 12 months to get long-term capital gains rates
• Harvest losses strategically (though keep an eye on crypto wash sale rules)

Best for: Investors who work with a crypto tax CPA or use professional-grade tracking. This is what we recommend to most COS Elite clients, it gives you the most options at tax time.

Rev. Proc. 2024-28: The Per-Wallet/Per-Account Rule

This is the rule that changed everything for crypto cost basis tracking, and most investors still don't know about it.

What it says: Starting January 1, 2025, you must track cost basis separately for each wallet and each exchange account. You cannot pool your cost basis across platforms.

What this means in practice:

Say you hold ETH on Coinbase, Kraken, and a Ledger hardware wallet. Before 2025, many investors (and tax software tools) would pool all their ETH into a single "universal" ledger and apply FIFO or HIFO across the entire pool.

That's no longer allowed.

Now, if you sell 3 ETH on Coinbase, only your Coinbase ETH lots can supply the cost basis. Your Kraken lots and Ledger lots are irrelevant to that sale.

Why this matters for cost basis methods:

• FIFO now applies per wallet, the oldest lot in that specific wallet gets sold first
• Specific ID can only reference lots in the wallet where the sale occurs
• Transfers between wallets get complicated, you need to document which specific lots you moved

This is one of the biggest reasons crypto investors need professional digital asset reconciliation. The per-wallet rule makes DIY tracking exponentially harder, especially if you use DeFi protocols or multiple exchange accounts.

For a deeper look at how trades between different crypto assets trigger taxes, see our breakdown on crypto-to-crypto trade taxation.

How 1099-DA Changes Cost Basis Reporting (2026+)

Starting in tax year 2025 (forms issued in early 2026), crypto brokers are required to issue Form 1099-DA, the Digital Asset equivalent of a 1099-B for stocks.

What 1099-DA reports:

• Gross proceeds from crypto sales
• Cost basis (if the broker has it)
• Whether gains are short-term or long-term
• Transaction dates and asset descriptions

The cost basis problem: Brokers will report cost basis only for assets purchased on their platform. If you transferred crypto in from another exchange or wallet, the broker likely has zero cost basis data for those coins.

When that happens, the 1099-DA will show your cost basis as "unknown" or zero. And the IRS gets a copy.

What this means for you:

If the IRS sees a 1099-DA showing $50,000 in proceeds and $0 in cost basis, their computer flags the entire $50,000 as a gain. You'll need to prove your actual basis with your own records.

This is where your cost basis method and documentation become critical. If you've been using Specific ID with proper records, you can substantiate your basis. If you've been winging it, 2026 is going to be a rough tax year.

Broker vs. taxpayer basis methods: Your broker will likely default to FIFO for the assets it tracks. If you use a different method (like Specific ID or HIFO), your tax return will differ from the 1099-DA. That's allowed, but you need records to back it up.

Worked Example: Same 5 Trades, 4 Different Methods, 4 Different Tax Bills

This is where cost basis methods go from abstract to concrete. Let's walk through a real scenario.

Your ETH purchases (5 lots):

Total holdings: 9 ETH | Total cost: $23,800

The sale: On May 1, 2025, you sell 3 ETH at $3,800 each. Total proceeds: $11,400.

Now let's see how each method handles this sale.

Under FIFO (First In, First Out)

Sells the oldest lots first:

• Lot 1: 2 ETH at $1,500 basis = $3,000 basis (long-term)
• Lot 2: 1 ETH at $2,800 basis = $2,800 basis (long-term)
• Total basis: $5,800
• Total gain: $11,400 - $5,800 = $5,600
• Character: 100% long-term capital gain
• Tax (at 15% LTCG rate): $840

Under LIFO (Last In, First Out)

Sells the newest lots first:

• Lot 5: 2 ETH at $3,400 basis = $6,800 basis (short-term)
• Lot 4: 1 ETH at $1,900 basis = $1,900 basis (short-term)
• Total basis: $8,700
• Total gain: $11,400 - $8,700 = $2,700
• Character: 100% short-term capital gain
• Tax (at 32% ordinary rate): $864

Under HIFO (Highest In, First Out)

Sells the highest-cost lots first:

• Lot 5: 2 ETH at $3,400 basis = $6,800 basis (short-term)
• Lot 3: 1 ETH at $3,100 basis = $3,100 basis (short-term)
• Total basis: $9,900
• Total gain: $11,400 - $9,900 = $1,500
• Character: 100% short-term capital gain
• Tax (at 32% ordinary rate): $480

Under Specific Identification (Optimized)

A crypto tax CPA would cherry-pick the best combination. Here, we select lots that balance high basis with favorable long-term treatment:

• Lot 2: 1 ETH at $2,800 basis = $2,800 basis (long-term)
• Lot 5: 2 ETH at $3,400 basis = $6,800 basis (short-term)
• Total basis: $9,600
• Total gain: $11,400 - $9,600 = $1,800
• Character: $1,000 long-term + $800 short-term
• Tax: ($1,000 x 15%) + ($800 x 32%) = $150 + $256 = $406

Look at that spread. The difference between the worst method (LIFO at $864) and the best (Specific ID at $406) is $458 on a single 3 ETH sale. Scale that across a year of active trading and the difference can be five figures.

Which Method Should You Use?

There's no single answer, but here's the decision framework we use with clients:

Use FIFO if:

• You buy and hold with minimal trading
• You don't have detailed lot-level records
• Most of your holdings are long-term anyway
• You want zero complexity

Use Specific ID (with HIFO ordering) if:

• You actively trade or have significant unrealized gains
• You work with a crypto tax CPA or use professional tracking software
• You can maintain contemporaneous records for every sale
• You want to minimize taxes legally

Avoid LIFO. There's no scenario where LIFO is better than Specific ID for crypto.

Important note on switching methods: You can change your cost basis method, but you cannot retroactively change past disposals. If you've been using FIFO and want to switch to Specific ID, the switch applies going forward. Lots already "used" under FIFO stay as reported.

If you earn crypto through staking or mining, your cost basis is the fair market value at the time you receive the coins. The method you choose then determines the order those lots get sold.

Common Cost Basis Mistakes

1. Pooling basis across exchanges. After Rev. Proc. 2024-28, this is flat-out wrong. Each wallet and exchange account is its own silo.

2. Forgetting transfer basis. When you move crypto from Coinbase to your Ledger, the cost basis travels with it. But you need to document which lots transferred.

3. Using $0 basis for airdrops, forks, or staking rewards. Many of these events have a cost basis equal to the fair market value at the time of receipt (which is also taxable income).

4. Retroactively "choosing" HIFO at tax time. Specific ID requires you to identify lots at the time of sale, not in April when you're filing. If you didn't designate at the time, you're stuck with FIFO.

5. Ignoring fees. Transaction fees, gas fees, and exchange commissions are all part of your cost basis. They reduce your gain.

6. Not reconciling with 1099-DA. Starting in 2026, if your reported basis doesn't match the 1099-DA, you need Form 8949 adjustments. Don't ignore mismatches, the IRS won't.

When You Need a Crypto Tax CPA

DIY cost basis tracking works if you have a simple portfolio: one exchange, buy-and-hold, minimal transactions.

But if any of these apply, you likely need professional help:

• You trade on multiple exchanges or use DeFi protocols
• You've transferred crypto between wallets without tracking lot movements
• You've received 1099-DA forms with missing or incorrect cost basis
• You want to use Specific Identification but haven't kept contemporaneous records
• You have unrealized gains over $50,000 and want to plan disposals strategically
• You've been using the wrong method and need to correct prior filings

At COS Elite, crypto cost basis optimization is a core part of our tax return preparation service. We reconstruct transaction histories, reconcile across wallets, and apply the method that legally minimizes your tax, all documented to withstand IRS scrutiny.

For investors with complex transaction histories across multiple wallets and protocols, our digital asset reconciliation service traces every lot from acquisition to disposal.