Mayor Bill de Blasio on Thursday officially announced a summons diversion program aimed at getting unruly homeless subway riders above ground and into shelters.

In the program — first reported by The Post on Tuesday and set to begin July 1 — vagrants approached by the NYPD for violating transit rules like fare beating and soiling trains will be given a chance to accept social services in place of a summons.

“New Yorkers want homeless people in the subway to receive the right interventions that will help them get back on their feet,” de Blasio said of the “Subway Diversion Project” in a statement. “Subjecting these individuals to criminal justice involvement for low level, non-violent offenses is not the answer and does not help anyone.”

Earlier this week, the MTA reported a 50 percent jump in incidents related to homeless people over the first three months of the year, compared to the same period in 2018. Of the 371 incidents through March, 84 percent caused service delays.

Officials estimate some 3,588 people live “unsheltered” in New York City, the majority of them on the subways. The city maintains a database of 1,700 known individuals living in such circumstances.

Under the diversion program, NYPD personnel and social workers from the nonprofit Bowery Residents’ Committee who determine that a vagabond is truly homeless and willing to receive services will accompany them to one of four homeless service centers.

From there, they will be referred to medical providers, overnight beds at smaller “safe haven” shelters, or the city’s longer-term shelter program.

Once individuals agree to accept services, BRC social workers will notify MTA and NYPD to waive their summons. But there is nothing stopping them from re-entering the transit system, Police Commissioner James O’Neill said at an event hosted by Crain’s New York.

“If you’re riding the subway and you’re homeless, if you’re committing a violation, of course, we’re going to address it,” O’Neill said. “Part of this diversion program is them agreeing to get help to go into a shelter. Now are we going to be able to prevent them after they go into the shelter from re-entering the subway? No – at this point we can’t even prevent recidivists that commit sex crimes from entering the subway.”

Homeless advocates decried the new policy as “misguided” – insisting that subway-dwellers should not be forced to move into the city’s notoriously unsafe shelter system.

“People avoid services and shelters for a variety of legitimate reasons, the most important being the shortage of safe, welcoming shelter beds and permanent and supportive housing,” Coalition for the Homeless Policy director Giselle Routhier said. “Reducing the tragedy of people taking makeshift refuge in transit facilities and on the trains means giving them somewhere better to go – not using the police to chase them in circles.”

Homelessness has soared under de Blasio — and with it, the cost to taxpayers. The city spends nearly three times as much on outreach to street and subway dwellers today as it did in 2013. MTA officials have struggled to rein in homeless-involved disruptions.

“Homelessness is a growing problem on the subway due to larger societal challenges that transit agencies are not designed to or capable of handling on their own,” subways chief Andy Byford told the Post.

Manhattan District Attorney Cy Vance called the diversion program “potentially life-altering.”

“Unsheltered people living in the subway need services — not arrests and court appearances for technical violations of transit rules,” Vance said.