The Denver Broncos linebacker did not specify which organizations. But he did write that they will "benefit the Denver community and others through the services, awareness and funds they provide for ... critical social issues."
These issues, he wrote, will include racial and gender equality, education and the relationship between communities and law enforcement, among others.
In the past, Marshall added, he has worked with the Rose Andom Center, a Denver-based organization that provides support for victims of domestic violence.
Marshall is one of at least 13 NFL players who have joined Colin Kaepernick in his pre-game protests during the playing of "The Star-Spangled Banner" this season.
Most of the players, like Kaepernick and Marshall, have kneeled while the anthem played. Others have stayed standing with their fists raised in a "black power" salute. Others still have made the less ideologically coherent gesture of linking arms during the song.
Kaepernick described his protest in August as a stand against police violence.
"I am not going to stand up to show pride in a flag for a country that oppresses black people and people of color," Kaepernick said, via NFL.com. "To me, this is bigger than football and it would be selfish on my part to look the other way. There are bodies in the street and people getting paid leave and getting away with murder."
Marshall has paid a price for joining Kaepernick's demonstration. So far, he has lost two endorsement deals: one from the Air Academy Federal Credit Union, and another from CenturyLink, a cable and communications company.
Now, like Kaepernick, he plans to give away his own money to causes that deal with the issues he's trying to draw attention to.
Kaepernick has said he will put his money "back into communities." Marshall's plan is equally vague — but his post did come paired with a photo of him standing with Denver Police Chief Robert White, with whom he met recently.
"I've had a lot of productive conversations with people I respect, including Chief White of the Denver Police Department," Marshall wrote. "I really appreciate all of them taking the time to listen to me and offer some insight and feedback on ways we can all make a difference."
It's worth monitoring where Marshall and Kaepernick's money actually goes — if only because their forebears have set a poor precedent. In at least two high-profile situations of late, wealthy sports figures have responded to protests against police violence by giving money in ways that actually exacerbate the problems they are ostensibly trying to solve.
In one example last week, Green Bay Packers head coach Mike McCarthy donated $100,000 to the Green Bay Police Foundation, a non-profit organization that was formed in June to "improve public safety and partnerships in our community."
"My goal is be part of the solution to make our community better," said McCarthy, according to ESPN.
But the Green Bay Police Foundation's first and only project has nothing to do with addressing racism at all. Rather, it is a fundraising effort to buy more tactical equipment for the police — specifically, ballistic vests and helmets.
The other example is Michael Jordan. The former Chicago Bulls-star and Charlotte Hornets owner spoke out against police violence in a blog post for ESPN's black issues site, The Undefeated, in July.
Then, he turned around and donated $1 million to the International Association of Chiefs of Police — a law enforcement advocacy group that opposes the demilitarization of police, wants to continue America's failed "war on drugs" and opposes restrictions on civil asset forfeiture, a policy that basically lets police officers take money and property from people they allege, but don't have to prove, are involved in criminal activity, then spend it as they see fit.