The bill was first approved by the Senate and then later in the day by the lower house - both of which are dominated by Morales' Movement Toward Socialism party - and now must be promulgated by interim President Jeanine Áñez.
The measure forbids reelection of anyone who has served the last two terms consecutively as president, effectively ruling out Morales, whose refusal to accept such term limits was a key issue in protests against him.
The measure did not set a date for the vote.
Morales' claim of victory and a fourth term in the election prompted massive protests that led him to resign on Nov. 10 at the army's suggestion. An audit by a team from the Organization of American States found widespread irregularities in that election.
After Morales left for asylum in Mexico, his own supporters took to the streets in protest.
Officials say at least 32 people have died in demonstrations since the presidential election, which would be annulled by Saturday's vote.
An agreement late Friday on elections between Morales' party and the interim government helped pacify the country. Street blockades were lifted, allowing supplies to reach marketplaces Saturday in areas that had been short of groceries and gas.
Sen. Oscar Ortiz said the bill calls for updating the electoral rolls, naming a completely new electoral tribunal to oversee the vote.
"We have to generate confidence in the population," said Sen. Omar Aguilar, from Morales' party.
Also Saturday, Áñez rejected a bill presented by Morales' party that would have prevented the ousted president from being tried for alleged crimes committed during the exercise of his functions to date.
"With respect to approving this bill in favor of those who have committed crimes and who now seek impunity, my decision is clear and firm: I will not promulgate this law," Áñez said.
The bill remains paralyzed, lawmakers said.
On Friday, the interim government accused Morales of terrorism and sedition for purportedly organizing highway blockades intended to prevent food from reaching some cities.
Acting Interior Minister Arturo Murillo said the complaint relates to a video in which Morales is supposedly heard in a phone call coordinating the blockades from Mexico. Murillo said Bolivia's government is seeking a maximum penalty, which is between 15 and 20 years in prison.
Morales has said the video is a "montage" by his opponents.