The posting system is the bridge between Asia’s top leagues and MLB: a Japanese (NPB) or Korean (KBO) club that controls a player’s rights can “post” him in the winter, opening a 45-day window to negotiate with all 30 MLB teams – with the signing club paying a release fee on top of the contract, scaled at up to 20% of the guarantee.
It’s the mechanism behind every blockbuster arrival from Tokyo and Seoul, and the fine print – especially the under-25 amateur rule – has shaped some of the sport’s most famous deals.
MLB ROSTER RULES
The Posting System
The 45-day bridge from NPB and KBO to MLB
WHO IT COVERS
NPB and KBO stars
Japanese and Korean players under club control
THE WINDOW
45 days
To negotiate with all 30 MLB clubs once posted
THE FEE
Up to 20%
A release fee paid on top of the contract, on a sliding scale
THE UNDER-25 TRAP
Amateur rules
Young stars fall under international bonus pools
How posting works
From Tokyo or Seoul to an MLB deal
| Step |
Detail |
| The club posts the player |
The NPB or KBO team – which holds his rights – agrees to make him available during the winter posting window; the player cannot post himself |
| 45 days of open negotiation |
Once posted, the player may negotiate with every MLB club simultaneously – a true open market, unlike the old highest-bid-wins system |
| The release fee |
The signing MLB club pays the posting club a fee on top of the contract: 20% of the first $25M in guarantees, 17.5% of the next $25M, 15% of everything above $50M |
| No deal, no move |
If the window closes unsigned, the player returns to his original club – and can be posted again in a future winter |
| The under-25 exception |
Players under 25 (or with under six pro seasons) are treated as international amateurs – capped bonus-pool money only, the rule that famously governed Ohtani’s arrival |
The economics on each side
Why everyone posts eventually
| Party |
The calculus |
| The NPB/KBO club |
Post a star a year or two before his international free agency and collect a fee worth tens of millions – or hold him and get nothing when he leaves free |
| The player |
Posting means arriving in MLB years earlier at market price – waiting for free agency costs prime seasons; the leverage to demand posting has grown accordingly |
| The MLB club |
The fee is a surcharge, not a bid – roughly 15-20% on top of the deal, which clubs treat as part of the all-in price when comparing posted players to domestic free agents |
| The fee’s tax treatment |
Release fees don’t count toward luxury tax payroll – a quiet reason posted stars appeal to CBT-squeezed contenders |
POSTING FACTS
The system replaced blind bids
Until 2013, MLB clubs submitted sealed posting bids for exclusive rights – a structure that produced $50M+ fees before anyone negotiated a salary.
Posting windows are winter-only
The system runs on an offseason calendar – a posted player’s 45 days tick through December and January, shaping each winter’s market timing.
The fee scales with the deal
The percentage structure means a $300M posted contract generates a fee near $50M – star postings are franchise-altering revenue for NPB clubs.
The Modern Mechanics
Today’s system is an open market with a toll: once posted, the player negotiates freely with every club, signs a standard, fully guaranteed MLB contract, and his former team collects the sliding-scale fee – 20% of the first $25M, 17.5% of the next $25M, 15% beyond $50M. The fee sits outside luxury tax payroll, a quiet sweetener for tax-squeezed contenders, and the signed player occupies a normal 40-man roster spot like any free agent. If the 45 days expire without a deal, he simply goes home, eligible to be posted again.
The Under-25 Rule That Changed History
The system’s sharpest edge: players under 25, or with fewer than six professional seasons, are classified as international amateurs – eligible only for capped bonus-pool money regardless of their star power. That rule is why the sport’s most famous two-way player arrived on a minor league contract with a modest bonus rather than a record deal: posting at 23 cost him hundreds of millions in the short run and bought him free agency years earlier. Every elite NPB or KBO prospect since has faced the same fork – post young and cheap, or wait for 25 and the open market.
Quick Answers
Can a player force his club to post him?
Not formally – posting is the club’s right. In practice, star players negotiate posting promises into their NPB/KBO relationships, and refusing a star’s request has real costs.
Who pays the release fee?
The signing MLB club, on top of the contract – it’s a surcharge in the all-in price, not money out of the player’s deal.
Does the posting fee count against the luxury tax?
No – release fees sit outside CBT payroll, one reason posted stars are attractive to clubs tight against the thresholds.
The Bottom Line
Posting is a 45-day open market with a 15-20% toll: the player gets all 30 bidders, the Asian club gets a franchise-altering fee, and the MLB club gets a star at a knowable surcharge. The one trapdoor – the under-25 amateur rule – remains the most expensive age line in professional sports.
