FIFO vs LIFO vs HIFO: Crypto Cost Basis Methods 2026 (US Per-Wallet Rule)

You bought Bitcoin three times in 2024 — at $30,000, $50,000, and $70,000. In 2026 you sell one Bitcoin for $90,000. What is your taxable gain?

The answer depends entirely on which accounting method you use. Use FIFO and your gain is $60,000. Use HIFO and your gain is $20,000. Same sale, same proceeds — but a $40,000 difference in taxable income that could cost you over $10,000 in tax.

This is the world of crypto cost basis methods. Understanding FIFO, LIFO, and HIFO — and especially the 2025 per-wallet rule that changed everything — is one of the highest-leverage things a US crypto investor can learn. Here is the complete 2026 guide.

What is cost basis?

Cost basis is what you originally paid for a cryptocurrency, including fees. When you sell, swap, or spend it, your taxable gain is the proceeds minus the cost basis. Get this number wrong — or fail to track it — and you can end up paying tax on the full sale amount, which is almost always wrong.

The complication: most active crypto investors buy the same coin multiple times at different prices. When you later sell, the IRS needs to know which specific units you sold. That is what cost basis methods determine.

The three methods, explained simply

FIFO (First-In, First-Out)

The oldest units are treated as sold first. If you bought BTC in January, March, and June, then sold some in December, FIFO treats the January BTC as the one you sold.

FIFO is the IRS default. If you do not document anything else, the IRS assumes FIFO. In a rising market, FIFO usually produces the largest gain — because your oldest units have the lowest cost basis.

LIFO (Last-In, First-Out)

The newest units are treated as sold first. If you bought BTC in January and again in June, LIFO treats the June BTC as the one you sold. In a rising market, this generally produces a smaller gain than FIFO — the recent purchase has a higher cost basis than the old one.

HIFO (Highest-In, First-Out)

The most expensive units are treated as sold first — regardless of when you bought them. HIFO is the most tax-efficient method in most cases, because selling your highest-cost units produces the smallest gain (or largest loss).

The critical distinction the IRS makes

This sounds like a technicality but it matters hugely. To use HIFO or LIFO, you must qualify for Specific Identification, which requires:

• The date and time each unit was acquired
• The cost basis and fair market value at acquisition
• The date and time of disposal
• The fair market value at disposal
• And, critically — the specific lot must be identified before the trade is executed, not retroactively chosen at tax time

Without that documentation, the IRS will default you to FIFO, no matter what method you intended to use. This catches many investors at audit time.

The 2025 per-wallet rule (this changed everything)

Starting January 1, 2025, the IRS requires cost basis tracking on a wallet-by-wallet and account-by-account basis. Before this, many investors used a “universal wallet” approach — treating all of their Bitcoin across every exchange and wallet as one pool. That is no longer allowed.

This was established in 2024 final regulations under § 1.1012-1(j) and applies to all crypto held by US taxpayers.

What this means in practice

If you hold Bitcoin on Coinbase, Kraken, and a hardware wallet:

• Each location now has its own independent cost basis ledger
• You cannot mix lots across them
• When you sell from Coinbase, you only choose from Coinbase lots
• FIFO, LIFO, or HIFO is applied within each wallet, not across all your holdings

If you transfer crypto between your own wallets, you carry the cost basis with it — but the receiving exchange usually shows “unknown basis” until you supply records.

Worked example: FIFO vs HIFO

Sara is a US freelance designer who bought Bitcoin three times in 2024, all on Coinbase:

• January: 1 BTC at $40,000
• April: 1 BTC at $60,000
• September: 1 BTC at $80,000

In 2026, she sells 1 BTC at $100,000.

Under FIFO: Sara is treated as selling the January coin. Gain = $100,000 − $40,000 = $60,000 taxable gain.

Under HIFO (Specific ID): Sara identifies the September coin as the one sold. Gain = $100,000 − $80,000 = $20,000 taxable gain.

At a 22% marginal rate plus 5% state tax (27% effective), the difference is:

• FIFO: $60,000 × 27% = $16,200 tax
• HIFO: $20,000 × 27% = $5,400 tax
• HIFO saves Sara $10,800 — legally.

When FIFO might actually be better

HIFO is usually the lowest-tax option in the short term, but FIFO has a hidden advantage in the US: it tends to push your gains into long-term capital gains territory faster. Long-term gains (held over one year) are taxed at 0%, 15%, or 20% federally — much lower than short-term ordinary rates that can exceed 37%.

Sometimes the older lot you would sell under FIFO is already long-term, while the newer lots you would sell under HIFO are still short-term. In that case, FIFO can produce lower tax overall, even with a larger nominal gain. This is one of the situations where professional tax software (or a CPA) earns its fee.

Average cost: not allowed in the US

Some other countries (including Canada and the UK) use an averaging method — pooling all units of the same crypto into one average cost. The US does not allow average cost for crypto. Crypto is classified as property, not as a security like a mutual fund, so the averaging rule that applies to mutual funds does not apply here. US taxpayers must use FIFO or Specific Identification.

Form 1099-DA and the 2026 broker reporting era

Starting with 2025 transactions (filed in early 2026), brokers must issue Form 1099-DA reporting gross proceeds. For 2026 transactions onwards, brokers must also report adjusted cost basis for “covered” digital assets — meaning assets that were both acquired and held within the same broker account.

This dramatically increases the IRS's ability to match what you report against what brokers report. The era of casual crypto tax reporting is over. If your numbers do not line up with the 1099-DA the IRS receives, expect a notice.

How to choose and apply a method

1. Decide before you trade. Specific Identification requires you to identify the lot before execution, not at tax time.
2. Use the same method consistently within a wallet for the full year. You can change methods between years, but not mid-year within a single wallet.
3. Keep contemporaneous records. Screenshots, exchange statements, transaction IDs, dates, and prices — archived as the year goes on, not reconstructed in April.
4. Use software. If you have more than 20 transactions a year across multiple wallets, manual tracking is not realistic. Modern crypto tax tools (Koinly, CoinTracker, CoinLedger, ZenLedger, Recap, and others) automate the per-wallet cost basis rule and let you compare FIFO vs HIFO outcomes before filing.

Common cost-basis mistakes to avoid

• Mixing wallets together. Post-2025, this violates IRS rules — even if it gives a better answer.
• Defaulting to zero basis. If you cannot find your cost basis, the IRS treats it as $0 — meaning your entire sale is taxable. Always reconstruct basis from exchange history before that happens.
• Switching methods mid-year. You must be consistent for each wallet across the tax year.
• Claiming HIFO without records. The IRS will reject HIFO at audit if you cannot show you identified the specific lots before the sale. Without records, FIFO applies.

Bottom line

FIFO is the IRS default and the simplest option. HIFO usually saves the most tax in the short term, but only if you have the records to support Specific Identification. As of 2025, all of this is applied per wallet — you cannot pool across exchanges. From 2026, brokers will report cost basis to the IRS via Form 1099-DA, making accuracy more important than ever.

The right method depends on your situation, but the wrong move is doing nothing — because doing nothing means FIFO with possibly missing basis, and that is the most expensive option of all. Use the calculator below to model your tax under different scenarios, and confirm your specific situation with a qualified CPA before filing.