If the stimulus package agreed to on Sunday is voted on Monday (December 21) and signed by President Trump as scheduled, the second stimulus check will be deposited into bank accounts as early as next week.

Treasury Secretary Steven Mnuchin told CNBC on Monday morning that the turnaround time for this direct payment will be much shorter than the first stimulus checks, which were parceled out over the spring and summer.

"The good news is that this is a very rapid way to get money into the economy," he said.

In other words, eligible taxpayers should begin receiving account transfers before January 1, and taxpayers who have not provided their bank account information to the IRS will then receive paper checks. After Congress passed the CARES Act in March, more than two weeks elapsed before the government began processing payments.

Mnuchin has said for months that the second stimulus check would arrive much sooner than the first.

The newly approved stimulus package will provide up to $600 to individuals in a single household, including children under the age of 17. The bill has not yet been finalized, but reportedly does not include payments to adult dependents or children past their 17th birthday.

If the guidelines mirror the CARES law, the payments would be lower for annual incomes above $75,000 and completely phased out for incomes above $99,000.

Stimulus check 2 is only half of the $1,200 that eligible Americans received in the first direct payment more than six months ago. Democratic leaders in both the House and Senate wanted a second round of $1,200 checks and included them in the HEROES bill passed by the House in May, but the Republican-controlled Senate balked at a second phase of relief legislation exceeding $1 trillion.

In early December, as bipartisan legislation drafted by Senate moderates began to win approval from more groups of lawmakers, self-described socialist Senator Bernie Sanders (R-Vermont) and Trump supporter Josh Hawley (R-Missouri) requested that it be added to the bill.

The bipartisan bill, which became the basis for the legislation being voted on today after being split in two, initially excluded the stimulus check in order to keep it below the Republican spending cap.

Last week, a group of left-leaning House Democrats went even further, calling for a $2,000 stimulus check. Later in the week, President Trump reportedly had to be persuaded to publicly demand the $2,000 check by White House aides who feared it would spoil delicate negotiations over the stimulus bill.