The move will help Trump consolidate the Republican Party apparatus under his leadership now that he has become the party's presumptive presidential nominee.
It marks an official departure from Trump's claim that he's self-funding his campaign, and allows him to repay himself for the money he has already spent, if he chooses to do so.
Under the deal, the Trump campaign and the RNC will establish two committees: Trump Victory and the Trump Make America Great Again Committee.
Trump Victory -- for which the maximum contribution is $449,400 -- will benefit 11 states whose Republican parties are part of the agreement: Arkansas, Connecticut, Louisiana, Mississippi, New Jersey, New York, South Carolina, Tennessee, Virginia, West Virginia and Wyoming.
Notably absent from that list: swing states. The only big general election battleground included is Virginia. The agreement doesn't cover states like Ohio, Florida and Colorado, where the race could be won or lost.
Helping Trump Victory will be Lew Eisenberg, the RNC's finance chairman. He'll work with Trump finance chairman Steve Mnuchin.
"Lew Eisenberg is going to do an outstanding job leading this effort," RNC Chairman Reince Priebus said in a statement announcing the deal. "Lew has already helped the RNC raise a record $135 million in support this cycle, and I have every confidence his track record of success will continue in this new role."
The Trump Make America Great Again Committee is a joint fundraising committee between the RNC and Trump's campaign.
Joint fundraising committees are a regular part of the presidential election process. Democratic front-runner Hillary Clinton has announced similar groups with the Democratic National Committee.
The biggest benefit of the joint committees is that they allow donors to write checks much larger than the $2,700 limit for individual candidates.
The joint fundraising agreement's structure will allow Trump to raise money not just for the general election, but for the primary -- taking advantage of a window to bring in extra money before he officially accepts the GOP's nomination. That could potentially allow Trump -- who regularly boasted that he was self-funding his campaign -- to reimburse himself for some of the millions of dollars he shelled out during his primary election fight.
Trump, however, said on Wednesday that he has "absolutely no intention of paying myself back for the nearly $50 million dollars I have loaned to the campaign."
It's not unusual to see states that aren't up for grabs in November included in joint agreements, because federal law limits the amount donors can give to $10,000 per state under such deals -- which means the more states that are included, the more money the candidate and the party can ask from each donor.
Candidates also tend to include state parties they have strong relationships with as another way to exert control over the money raised. For instance, Mitt Romney's joint fundraising agreement in 2012 funneled money to Utah and Massachusetts -- states where Romney owned homes and had existing relationships.
The $449,4000 limit includes a maximum limit of $2,700 for the Trump campaign's general election fund, $33,400 for the RNC, $110,000 for the 11 state parties and hundreds of thousands of dollars for party's building, legal and convention funds.
"We are pleased to have this partnership in place with the national party," Trump said in a statement. "By working together with the RNC to raise support for Republicans everywhere, we are going to defeat Hillary Clinton, keep Republican majorities in Congress and in the states, and Make America Great Again."