Since 2021, New Yorkers have been rightly puzzled by OnPoint NYC, the “safe injection” sites where hard-drug addicts shoot up under medical supervision.

After all, drugs like fentanyl and heroin are illegal under federal law.

Addicts using the service have bought their drugs illegally, and may have committed crimes to finance their habits — yet police have turned a blind eye.

Now we know why OnPoint could be confident it would not face a federal crackdown: The Biden administration was actually helping finance it.

This week my research found that under President Joe Biden, the federal Substance Abuse and Mental Health Administration quietly awarded the program a $2 million annual grant — and paid out just over half of it. 

That grant, revealed here for the first time, has been terminated under President Donald Trump, SAMHSA Principal Deputy Assistant Secretary Art Kleinschmidt told me.

OnPoint, he said, was “a misguided harm reduction program that [was] incompatible with federal law and applicable Executive Orders.”

Indeed, Trump’s July 25 order specifically barred funding for “safe consumption efforts that only facilitate illegal drug use and its attendant harm.”

True: Acquiescing in drug use only serves to encourage it — as well as other outrages documented by The Post, including sidewalk sex and drug dealing outside OnPoint’s sites in East Harlem and Washington Heights. 

But unless Trump’s Justice Department moves to shut down OnPoint — the only such program in the country — federal defunding won’t pull the plug on its dangers. 

The SAMHSA grant was just a small part of OnPoint’s $14 million annual budget, which includes millions in taxpayer dollars from New York state and New York City, along with private funding from the New York Community Trust, the Open Society Foundation, Deutsche Bank and others.

If law enforcement doesn’t shutter the program, the city should push OnPoint to reform itself into a pathway toward long-term help for the addicted — especially those who are mentally ill and can threaten public safety. 

OnPoint likes to emphasize that it has prevented some 1,800 overdoses among the 6,300 addicts it’s served, and there’s no reason to dispute that claim.

But it has not educated its clients that drug use is fundamentally undesirable. 

Its mission statement tells the story: “We combat stigma and embrace people who use drugs and engage in sex work instead of pushing them to the margin.”

Yet OnPoint could do much more than just accept drug use as a valid lifestyle choice. 

It could help us learn important information about the addicted, including statistics on how many have overdosed and died elsewhere, how many have been arrested for assault or robbery, and crucially, how many have sought treatment to beat their drug habit.

A reformed and constructive OnPoint would seek such data — perhaps through required electronic ankle bracelets — to not just reduce overdoses, but to reduce addiction itself.

Surprisingly, the Canadian province of British Columbia, which pioneered “harm reduction” sites in the city of Vancouver, is now going in exactly that direction.

Last September, the province passed a law permitting involuntary commitment for both psychiatric problems and substance abuse — a policy New York state legislators have rejected.

If British Columbia’s law was in place here, it could mean that anyone seeking “supervised injection” at OnPoint would have to agree to enter drug and mental health treatment —voluntarily or not. 

It would mean tracking those individuals so as to develop a truly “evidence-based” approach that goes beyond short-term overdose prevention.

Such an approach is in keeping with Mayor Eric Adams’ proposed Compassionate Interventions Act, which he says will “give clinical professionals the authority they need to bring someone who appears to pose a danger to themselves or others due to substance use disorder to a hospital and allow a judge to mandate treatment if the person is unwilling to enter treatment voluntarily.”

From the chaos of public drug use in Harlem, The Bronx and Jackson Heights, to mass shootings by the untreated mentally ill, it’s clear that involuntary treatment, once common across the country, needs to be adopted once again.

OnPoint NYC could become a useful front door for both drug addicts and the mentally ill who are willing to seek treatment. 

It could serve as well to steer those merely seeking to use drugs safely toward programs that will help them rebuild their lives — without their addictions.

For that to happen, both New York’s laws and OnPoint’s mission would need to get clean as well.

Howard Husock is a fellow at the American Enterprise Institute and author of the forthcoming book “The Projects: A New History of Public Housing.”