The executive branch can create law in a number of different ways. As a result, there are several different types of sources for administrative law. These sources include:
- Rules and regulations (quasi-legislative activities)
- Decisions in cases brought before agency tribunals (quasi-judicial activities)
- Executive orders and proclamations
In addition to these sources of binding administrative law, agencies also create a wealth of guidance documents that, although not binding, are often useful.
As with most areas of U.S. law, both the federal and state governments create administrative law.