The countdown is on for New Yorkers still swiping.

After Dec. 31, commuters won’t be able to buy or reload a MetroCard, as the MTA makes its full transition into the OMNY era.

Some riders say they’re frustrated about saying goodbye to a system they’ve used their whole lives, while others say they’re ready for the tap-and-go upgrade.

To help everyone adjust, the MTA is sending its mobile sales vehicles into neighborhoods across the city throughout December. It will give riders a chance to ask questions, get help setting up OMNY and understand how transfers and payment options will work.

On Dec. 12, the team will be out in Bensonhurst at 86th Street and Bay Parkway from 10 a.m. to 12 p.m. and then in Bay Ridge at 86th and Fourth Avenue from 1 p.m. to 3 p.m.

On Dec. 16, they will be in Starrett City from 9:30 a.m. to 11:30 a.m., followed by two stops in Flatlands. The first stop will be around 12:30 p.m. on Flatlands Avenue and then from 2 p.m. to 4 p.m. at Kings Plaza.

And after the holiday, Dec. 26 brings more locations: it's back to Bensonhurst and Bay Ridge, plus stops in the Bronx at Knolls Crescent Mall and Fordham Plaza, where staff will be available through mid-afternoon.

The full year-round schedule is available on the MTA’s website.