Congressional Democrats are asking regulators whether they explored possible risks connected to Bank of America Corp. (BAC)’s moving of derivatives from Merrill Lynch into its deposit-taking unit after a credit downgrade.

Eighteen lawmakers signed onto letters from Representative Brad Miller and Senator Sherrod Brown seeking information about whether agencies consulted on the transfer considered the potential impact on the bank’s health and customer accounts.

“Because of the favored treatment of derivative contracts in receivership, it appears highly likely that losses on derivatives would result in losses to insured deposits ultimately borne by taxpayers,” Miller wrote in his letter, which was signed by eight House Democrats. The transfers were first reported by Bloomberg News on Oct. 18.