The I.R.S. has ruled that some currencies like Bitcoin are an asset and subject to capital gains; donors can also see how the charity spends the money.
Like many Americans, Brad Hines spent much of September watching hours of hurricane coverage on television.
For Mr. Hines, a digital marketing strategist in Boston, the storms hit close to home: Several family members in Florida were affected by Hurricane Irma. As the devastation unfolded, he opened his computer and donated money to the Red Cross, but it was not in cash.
He gave in Bitcoin, which the Red Cross has been accepting since late 2014. He could have donated dollars, but, he said, the more he can use the cryptocurrency for buying goods and giving to charity, the more it will be used by others.