The two methods are:
- An amendment can be proposed by two-thirds votes of both Houses of Congress, and ratified by three-fourths (38 out of 50) of state legislatures within a seven-year time span.
- An amendment can be proposed by a constitutional convention called by Congress on petition of two-thirds (34 out of 50) of state legislatures, and ratified by three-fourths (38 out of 50) of state legislatures.