The IRS says exchanges of one type of crypto for another are taxable, even if no cash changes hands. However, what about before January 1, 2018, was it tax free? You didn’t get cash, so there shouldn’t be any income or gain for the IRS to tax, right? If the IRS mines all the crypto data it is getting and audits you, will they allow it? The tax law was changed by statute to say that starting January 1, 2018, crypto trades are taxable. By implication, doesn’t that mean they were tax-free in 2017 and before? You might think these questions are no longer relevant, since 2017 is long gone. 2017 tax returns were due on April 15 or October 15 of 2018. The normal three-year statute of limitations should run three years after you file your return. But a six year statute of limitations may apply to many of these situations, giving the IRS until sometime in 2024 to audit.