President Gianni Infantino's favored format would break with soccer tradition to play in groups of only three teams. Two would advance from each group to a Round of 32 knockout bracket.
If agreed by the Infantino-chaired FIFA Council in Zurich, the 2026 hosting contest could formally open in weeks. A co-hosted North American bid is widely seen as the best option.
Here are some things to know about overhauling the greatest competition in the world's most popular sport:
A bigger World Cup was an Infantino campaign promise before his election last February, when his plan was 40 teams.
It might have been key. Infantino's momentum for victory in a second-round poll was a three-vote lead over Sheik Salman of Bahrain in the first. Sheik Salman had promised only to review if more World Cup teams were wanted.
Infantino also pledged to give more of FIFA's money to member federations - all 211 are now entitled to $5 million from each World Cup - and send more to continental and regional soccer bodies.
So, more teams also had to mean more games, earning more revenue from broadcasters and sponsors.
The "16x3" format arguably works better with only group winners advancing. But that would leave total matches unchanged at 64.
Infantino also wants to create fervor in the extra countries which would qualify.
In the short-term, competing national teams attract more sponsors. The long-term goal is appealing to more young people who are the future players, fans and officials.
Expect to hear much FIFA talk of helping the next Costa Rica or Iceland - feelgood stories at the 2014 World Cup and Euro 2016 - by inviting 16 more teams to the party.
A near-consensus is growing around the "16x3" option revealed just one month ago.
All 80 games would be played in exclusive time slots. That's more hours of TV exposure for sponsors and sales time for broadcasters in the same 32-day tournament period.
By advancing two teams from each group, a Round of 32 ensures most teams still play at least three matches.
FIFA's own analysis predicts this format will raise revenue by 20 percent from the equivalent $5.5 billion forecast from the 2018 World Cup in Russia.
The flaw for purists is planning for penalty shootouts to settle drawn group matches. If each game has a "winner" that guards against teams colluding on a mutually favorable result in the last group games.
Previously, Infantino suggested an opening playoff round of 16 matches to decide who would join 16 seeded teams in a traditional 32-team group phase.
That was unacceptable to many FIFA members federations who said "one-and-done" teams were not part of a real World Cup.
It also would stretch the tournament to 39 days.
Infantino's plan from one year ago is now almost friendless.
Either of two options, 10 groups of four teams or eight five-team groups, gives lopsided or weak match schedules, FIFA judged.
In "10x4," only 76 matches are played and only six group runners-up advance from a muddled tiebreaker process to a Round of 16.
In "8x5," the 88 matches include meaningless ones in a flabby group phase ripe for collusion. Also, the four semifinalists would play eight matches and that workload is unacceptable to European clubs releasing employees to national-team duty.
PROVEN 32-TEAM FORMAT
Why fix something that is not broken? Germany, the defending champion, has publicly asked this question.
The 32-team format and perfect 64-match bracket has worked well since being introduced at the 1998 World Cup in France (where Europe had 15 teams).
FIFA acknowledged that it produces the best soccer - "the highest absolute quality" of games pitting high-ranked teams against each other.
Recall that former winners Italy, England and Uruguay were drawn in the same 2014 World Cup group - and yet Costa Rica finished top.
Still, enough of FIFA's 211 members want change and their chance to play.
WHO WILL PLAY?
A big question is likely not being resolved Tuesday.
FIFA has yet to announce exactly how many entry slots each of six confederations would get for their own qualifying program.
Quotas for a 40-team World Cup were proposed in December 2015 by a FIFA advisory group that included Infantino, then UEFA's general secretary.
Some saw a cynical move to sweeten skeptical FIFA voters who were being asked to vote through modernizing and anti-corruption reforms on the same day they picked a new president.
Then, assuming a single host nation would get automatic entry, the proposal for sharing 39 qualifying slots was: Europe 14; Africa 7; Asia 6; South America 5; North, Central America and Caribbean 5; Oceania 1; plus a final slot awarded "based on sporting merits using a method yet to be defined."
Going from 40 to 48 can add at least one more from each continent.
Who could those new teams be?