An NYPD sergeant who allegedly killed an Upper East Side doorman while driving against traffic on the Taconic State Parkway after an off-duty drinking binge resigned Wednesday from the NYPD, a department spokeswoman confirmed.

Sgt. Tiffany Howell, 47, is charged with aggravated vehicular homicide, manslaughter and vehicular manslaughter in the Jan. 22 death of Manuel Boitel, 61, who was on his way home from work when he was killed, according to state Attorney General Letitia James.

An 18-year NYPD veteran, Howell’s resignation comes two years before she would have earned her full pension, but preempts an administrative hearing that was scheduled for 10 a.m. Thursday that could have resulted in her termination.

By resigning before she could be fired, Howell remains entitled to a portion of her pension, which she’ll be able to access in early 2028.

Howell was initially expected to retire in February, but at some point reversed the decision. In resigning, she is no longer entitled to a so-called “good guy letter,” which would allow her to carry a firearm post-retirement.

At the time of the crash, Howell’s blood-alcohol level measured 0.26 — more than three times above the legal limit of 0.08 — prosecutors said.

Howell was driving her Infiniti southbound in the northbound lanes of the Taconic State Parkway in Mount Pleasant when she slammed into Boitel’s Toyota around 11:37 p.m., James said. Howell was driving more than 50 mph, the attorney general added.

Medics rushed Boitel to Westchester Medical Center, but he could not be saved.

Boitel was returning home from his job as a doorman at Manhattan’s St. Tropez luxury condominium building on E. 64th St. near First Ave.

Howell had just left a “Holy Smoke 2026” cigar social she helped organize at Mom’s Cigar Warehouse in Scarsdale, according to NYPD sources. The social featured an open bar, buffet-style dinner and premium cigars.

Allison Stuart, a prosecutor in James’ office, which investigates deaths in which police officers are involved, said video from the “social event” Howell attended showed her having several drinks and that she later left alone. Howell initially drove north on the parkway’s northbound lanes before reversing course and heading in the wrong direction, causing the crash, according to reports.