Much has been said and written about changes that incoming President Donald Trump and the newly Republican-controlled Congress will implement on Day One or in the first hundred days of the Trump administration. Among the changes are the repeal of the Affordable Care Act, or Obamacare, tax cuts, and spending increases in certain programs including Defense and Homeland Security. Also widely discussed is Congress’ intent to use the Budget Reconciliation process, which limits the ability of Democrats to use filibusters to indefinitely delay or to kill legislation that is not to their liking.

But here is something that has gotten little to no attention – laws passed using the Budget Reconciliation process that are not revenue neutral cannot be effective for more than 10 years. This means that many, if not all, of the laws passed using Budget Reconciliation will not be permanent law and will expire in 10 years or less.

We’ve seen this before, most notably with the George W. Bush tax cut of 2001 known as the Economic Growth and Tax Relief Reconciliation Act of 2001 (EGTRRA.) The EGTRRA cuts, which expired in 2010, included among other things, cuts to the estate tax (including one year, 2010, when there was no estate tax), lowered tax brackets, including a new 10% tax bracket, and reduced capital gains taxes. After 2010, some provisions were made permanent, some provisions, like the estate tax rate and capital gains tax rate, were made permanent with changes, and other provisions were allowed to expire.

Budget Reconciliation was passed as a provision in the 1974 Congressional Budget Act (CBA), intended to be used to force reductions in spending and reduce the federal deficit. However, in 1975 Sen. Russell Long (LA.) discovered that the CBA could also be used to limit debate and force a vote on his tax cut bill. Budget Reconciliation was used several more times over the next 20 years and then in 1995 the Byrd Rule amended the CBA to prohibit the use of Budget Reconciliation for provisions that would increase the deficit beyond 10 years. In 1997 Congress used the Reconciliation Process to pass the Taxpayer Relief Act of 1997, which was a tax cut that increased the deficit, but avoided the Byrd Rule by pairing the bill with the Balanced Budget Act of 1997 that reduced spending. In 2000 the Byrd Rule was amended to prohibit using multiple bills to arrive at a revenue-neutral result.

So as the reports of budget bills being passed and signed come in, be alert for changes that passed under the Budget Reconciliation process, because they’ll be back in a few years.