I am a CPA who specializes in cryptocurrency taxation and DeFi yield farming is one of the most complex areas I deal with. Let me provide some clarity on the current IRS position as of 2025-2026. The IRS has not issued specific guidance on DeFi yield farming, but we can derive the treatment from existing guidance on crypto staking, lending, and general tax principles.
When you provide liquidity to a pool and receive LP tokens in return, this is likely a taxable exchange. The fair market value of the LP tokens at the time of receipt becomes your basis in those tokens, and you may need to recognize gain or loss on the underlying tokens you contributed. This is similar to how the IRS views contributing assets to a partnership, though the analogy is not perfect.
Yield farming rewards, whether they come as trading fees, governance tokens, or additional LP tokens, are almost certainly taxable as ordinary income at the time of receipt. This is consistent with the IRS position on crypto staking rewards established in Revenue Ruling 2023-14. The fair market value at the time of receipt is your income and becomes your basis in the received tokens.
The biggest practical challenge is tracking cost basis across multiple protocols, chain migrations, and token swaps. I strongly recommend using a dedicated crypto tax software like Koinly, CoinTracker, or TokenTax. Manual tracking is virtually impossible for active DeFi users. Also, keep in mind that impermanent loss is not directly deductible as a realized loss. You only recognize the loss when you withdraw liquidity and actually dispose of the LP tokens. The tax treatment of impermanent loss is an area where guidance is desperately needed and I expect the IRS or Treasury to address it eventually.