Nassau University Medical Center has changed its admission policy for its drug and alcohol detoxification program.

Officials say patients can no longer walk in off the street and hope to get a bed. Now, they must call ahead and be put on a list. It may be a matter of days before there's space for a patient.

NUMC now has the only program on Long Island dedicated to detoxification, so officials say they've seen a dramatic increase in the number of people seeking treatment.

"Any given morning, between 15 to 20 individuals would walk in seeking treatment," an NUMC spokesperson says. "The beds would fill quickly, and the vast majority would leave, most never to come back for another admission. We designed the new appointment system to ensure that individuals would be offered a bed and be guaranteed that this bed will be available to them."