A framework for following the news, because player movement is run by a rulebook. Every move a team makes is one of three things: retaining its own player, signing a new one, or trading. Where the team sits on the ladder below decides which of the three are still open to it.
Salary cap rules live in the Collective Bargaining Agreement, the contract between the league and the National Basketball Players Association. The current one was signed in 2023. It sets the thresholds, the exceptions, and the penalties, and it is renegotiated periodically.
The cap itself moves annually because it is tied to league revenue. Figures below are 2025-26.
| Rung | 2025-26 | What it does |
|---|---|---|
| Salary floor | $139.2M | Minimum spend. Shortfalls go to your players anyway. |
| Salary cap | $154.6M | Crossable only through named exceptions. |
| Luxury tax | $187.9M | Every dollar over is taxed, in escalating brackets. |
| First apron | $195.9M | Roster-building tools start being removed. |
| Second apron | $207.8M | Most remaining tools gone; draft picks attacked. |
It is a soft cap. You may cross the cap line, but only through specific authorizations called exceptions. There is no general permission to exceed it, only a list.
Every contract on the books counts toward one team salary total, and that number puts a team in one of two states.
Under the cap: real space to sign anyone, but the big exceptions are forfeited.
Over the cap: no space at all, and players are added only through exceptions or trades.
The most common condition. A team does three things from here: keep its own players, sign new ones, and trade for them. Keeping is nearly unrestricted. Signing and trading are governed by two separate systems.
Signing runs on exceptions: named permissions to add salary while over the cap.
Trading runs on salary matching: what you send out must roughly cover what you take back.
A hard cap would force teams to release their own stars the moment they got expensive. Bird rights1 exist to prevent that: they let a team exceed the cap, the tax, and both aprons for one purpose only, re-signing a player already on its roster. Retention is the one thing the entire penalty system never touches.
They come in three tiers scaled to how long the player has been yours.
| Tier | Earned after | Can pay up to | Length |
|---|---|---|---|
| Full Bird | 3 seasons | The max salary, 8% raises | 5 years |
| Early Bird | 2 seasons | Greater of 175% of last salary or the league average | 2 to 4 years |
| Non-Bird | 1 season | Greater of 120% of last salary or 120% of the minimum | 4 years |
So retention is unrestricted for a player you have had three years, and constrained below that.
That constraint has teeth. Take an unrestricted free agent who arrived two seasons ago: his own team holds only Early Bird rights, so the most it can offer him is near the league average, roughly mid-level money, however much he is now worth. The permission to exceed the cap is real, but below the third season it stops well short of the max. The escape hatch is restricted free agency, where the right to match an offer sheet works at any payroll and needs no exception at all.
The clock asymmetry. Bird rights travel with a player in a trade, so the acquiring team inherits his accumulated seasons. They reset to zero if he changes teams as a free agent. This asymmetry is the entire reason sign-and-trades exist.
Restricted free agency. A second retention tool. Extend a young player a qualifying offer and you hold the right to match any offer sheet he signs elsewhere. Heavy team leverage, and the reason these standoffs run for months.
Three tools, in descending order of size.
| Tool | Max starting salary | Length | Notes |
|---|---|---|---|
| Mid-level exception (MLE) | $14.1M | 4 yrs | One mid-sized slot per year. The primary way a capped-out contender adds a real rotation player. |
| Bi-annual exception (BAE) | ~$5M | 2 yrs | Usable only in alternating years. |
| Minimum contract | League min | up to 2 yrs | Always available to every team at any payroll. No team is ever unable to sign anyone. |
The figures are first-year salaries; raises are added on top over the life of the deal. These are the full-strength versions, held by a team over the cap but below the first apron. Each apron shrinks or removes them, which is the subject of the penalties section.
Trades use salary matching: what you send out has to roughly cover what you take back.
Combining two or more outgoing contracts so their sum matches one larger incoming contract: three role players out, one star back. No single contract on the roster is big enough to cover a $40M star, and the band demands roughly $32M going the other way, so the team bundles three deals of about $11M each until the sum clears it. This is the everyday machinery of blockbuster trades.
Send out more salary than you take back and the difference is banked as a credit. Shed $30.7M, take back $8.2M, bank roughly $22.5M. The TPE absorbs one incoming contract in a later trade with nothing sent out to match it. It is homemade cap space for a team that has none.
A star wants to leave Team A for Team B, but B is over the cap and can only offer him the mid-level. Signing outright costs him tens of millions and leaves A with nothing. So A re-signs its own free agent first, using Bird rights to pay him well past what B could offer, then trades that contract to B under normal matching. The Bird-sized value rides along with the player.
| Party | What it gets |
|---|---|
| The player | A Bird-sized contract instead of a mid-level one, on the team he wanted. |
| The old team | Players and picks instead of nothing. |
| The new team | A player it had no room to sign. |
Nothing in it is a new rule. It is Bird rights and salary matching arranged in sequence. Matching still applies to the trade leg, and the resulting contract must run either 3 or 4 years, with only the first year fully guaranteed.
That length cap is deliberate. Before 2011 a sign-and-trade could run five years, which made leaving as lucrative as staying. The current rule holds sign-and-trade deals to the same four-year ceiling a team with cap room faces, so that the five-year contract remains available only from your own team, re-signing outright.2 The financial incentive to stay put is the point.
Rare. Entering 2025 free agency, exactly one team, Brooklyn, had meaningful cap space, roughly $35M. A couple of others could manufacture some by giving things up. The rest of the league was over the cap. Seven teams used room in 2024.
Spend the room and you are an over-the-cap team with a worse toolbox.
Everything above describes a team's full toolbox. This section is what gets taken back as payroll climbs.
Low on the ladder you pay nothing. In the middle, above the luxury tax line, you pay money. At the first apron you stop paying money and start paying in tools, and at the second apron in draft picks. The change of currency is the whole design. A fine you can afford is a price, and the owners the league most wanted to constrain were exactly the ones who could pay it.
Above $187.9M every dollar is taxed, in brackets that grow steeper as you climb. A team that has paid the tax in three of the previous four seasons pays a higher repeater multiplier at every bracket. The compounding is severe enough that shedding modest salary can save several times that amount in tax.
Every apron restriction blocks bringing in outside talent. Bird rights, the tool for keeping your own, is untouched at every level. The message is not "you cannot be expensive." It is: stay as expensive as you like keeping the team you built, but you may no longer shop for more.
Here is the toolbox shrinking. This single table is the apron system.
| Tool | Over cap, below apron 1 | Over first apron | Over second apron |
|---|---|---|---|
| Bird rights | Full | Full | Full |
| Mid-level exception | $14.1M / 4 yrs | $5.7M / 2 yrs | None |
| Bi-annual exception | ~$5M | Gone | Gone |
| Minimum contracts | Yes | Yes | Yes |
| Salary matching | 125% + $100K | 110% | No more than sent |
| Aggregation | Yes | Yes | Banned |
| Prior-year TPEs | Usable | Unusable | Unusable |
| Sign-and-trade in | Yes | Banned | Banned |
| Buyout signings | Any player | Not if his old salary topped ~$12.4M | Not if his old salary topped ~$12.4M |
| Cash in trades | Yes | Yes | Banned |
Read down the MLE row: a $14.1M offer to an outside free agent collapses to $5.7M, then to nothing. Above the second apron your entire pitch to an outsider is a minimum contract, however much the owner is willing to spend.
Read the second-apron column and the difference is one of kind, not degree. The first apron takes away ways to sign people. The second apron strips the machinery of trading itself. With aggregation banned you would need a single outgoing player large enough to match a star on his own, and almost no team has one. Functionally, a second-apron team cannot trade for a star.
Together these do not force a breakup. They make staying together self-defeating, by removing the two things a team needs to stay good: trade flexibility and draft capital. Hence the nickname "dynasty killer."
In the summer of 2025 Boston traded Jrue Holiday and Kristaps Porzingis, two starters from a team that had won the title fourteen months earlier. Jayson Tatum had ruptured an Achilles and the season was likely lost. Ownership could pay the bill, reported near $500 million with tax included. What they would not absorb was what came attached to it. Brad Stevens, their president of basketball operations:
"The second apron is why those trades happen. The basketball penalties associated with those are real."
Both were straight salary-matched trades. No exception was involved anywhere, because trades do not run on exceptions. Moving Porzingis at roughly $30.7M for Georges Niang at roughly $8.2M is what dropped them under the second apron, and because they were deep in repeater territory the reported tax saving was around $40M on a salary cut of about $22.5M.
The NBA is a soft cap, but certain moves bolt a temporary, self-inflicted hard cap onto the team that makes them: a line it cannot cross for the rest of the season, no matter what Bird rights it holds.
| Do this | Hard cap lands at |
|---|---|
| Use the full non-taxpayer MLE | First apron |
| Use the bi-annual exception | First apron |
| Acquire a player via sign-and-trade | First apron |
| Use the taxpayer MLE | Second apron |
So there are two different ways to be at an apron: climb over it and live under the restrictions, or trigger a wall from below by reaching for a big tool. The logic is consistent. The tools the first apron forbids from above are exactly the ones that pin you underneath it from below.
The whole system collapses to one question: how do I legally absorb incoming salary?
Everything else is a modifier on those two answers. The aprons do not add new rules so much as delete options from them, and the penalty currency shifts from money to tools to picks as you climb. A team keeps its own players freely at every level. What it loses, progressively, is the ability to go get anybody else.