A new group of lawmakers is attempting to get answers from the U.S. Internal Revenue Service on its tax requirements for digital currencies like bitcoin.

Representatives Jared Polis and David Schweikert, co-chairs of the Blockchain Caucus congressional group, recently penned a letter addressed to IRS Commissioner John Koskinen, urging the tax agency to “issue additional guidance on the tax consequences and basic tax reporting tax requirements for transactions using virtual currencies.”

“While the IRS has taken steps to provide some information to tax payers regarding the tax treatment of virtual currency, additional information and guidance could assist businesses that facilitate virtual currency transactions and purchases and individual tax payers to increase reporting on income gained or loss on virtual currency transactions,” the letter stated.

In their letter, the two lawmakers cited the recommendations made by the Treasury Inspector General for Tax Administration (TIGTA), which criticized the IRS in November for not doing enough when it comes to addressing income streams produced via cryptocurrency. Polis and Schweikert urged the IRS to “consider the recommendations of the TIGTA and take action based on those recommendations.”