When we hear the word “chimp,” most of us think of that fury primate at the zoo or the subjects of a Jane Goodall documentary. In Washington, CHIMPs are not animals, but a notorious budget gimmick. This budget gimmick, short for Changes in Mandatory Programs, has been used to avoid budget restraints by increasing discretionary spending—most recently by $19 billion this fiscal year.

The budget is divided into three main spending categories: discretionary, mandatory, and net interest. Discretionary spending is the bucket of money that must be appropriated each year for select programs to be funded. Unlike mandatory spending, or federal funding that is primarily on autopilot (e.g., Social Security and Medicare), discretionary spending has specific budget enforcement rules and spending caps.

As is often the case, when Congress decides it doesn’t want to stick to the spending levels written in law, accounting tricks are applied. Frequent targets of this accounting fiction are mandatory programs, like the Crime Victims Fund (CVF). The CVF can be monkeyed with (no pun intended) by creating fake spending offsets that permit levels of spending higher than would otherwise be allowed under current budget rules and federal law.

Let’s take a closer look. The CVF is a mandatory program funded by federal fines, forfeited bail bonds, and other federal criminal penalties. This money is then used by the CVF to provide grants to state and local governments to compensate crime victims. But instead of actually being used for such a purpose, the account is used as a yearly budget gimmick. We can illustrate this by using an example similar to the one provided by Senator Jeff Session’s (R–AL) Honest Budget Act.

Assume that the CVF has $10 billion coming into its bank account, available to be expended for CVF purposes. In other words, the CVF has $10 billion in budget authority. However, it’s unlikely that all that money will go to help crime victims this year, so the actual spending from the account will be something much lower. Instead of reserving the excess budget authority to help crime victims in the future, a so-called CHIMP provision is inserted into the appropriations bill, delaying the use of such funds. Since the money was not spent on its designated activity, budget score keepers count that as “saving” $10 billion in budget authority even though all $10 billion would not have otherwise been spent. This frees up $10 billion in budget authority to be used for the CVF’s intended purpose, or to be used to increase spending in future years. When used for the latter, the $10 billion “savings” resets each year, and each year Congress delays it to “offset” higher levels of new spending.

Over a 10-year period it could be said that Congress saved $100 billion ($10 billion CVF reduction X 10 years). In reality, the savings are only $10 billion—after all, that’s all that is in the account. Congress simply re-uses that same $10 billion to offset higher spending levels each and every year. However, the accumulated new spending amounts to $100 billion over the 10 years.

The CVF is the most frequently abused spending account. For example, the most recent omnibus appropriations, the Consolidated and Further Continuing Appropriations Act of 2015 (H.R. 83), spent $10.5 billion that was allegedly “offset” from money in the CVF. But the CVF isn’t alone. Among others, H.R. 83 applied the CHIMP gimmick to the Children’s Health Insurance Program, increasing discretionary spending by another $6.3 billion. All in all, Congress increased the funding appropriations bill by more than $19 billion by applying dishonest accounting methods like CHIMPs.

As Congress begins the process of conferencing the budget resolutions, legislators should make sure that budget enforcements are strengthened to prevent these budget gimmicks from being used in the future. The recent Senate Budget Resolution took a good step in the right direction: The budget slowly phases out the use of CHIMPs, and in doing so, saves approximately $131 billion over 10 years.