I-890 begins at the toll booth for exit 26 of the New York State Thruway in the Schenectady County town of Rotterdam. It initially heads to the east, connecting to NY 890 and NY 5S by way of a modified trumpet interchange that directly feeds into the Thruway junction. At this point, I-890 takes over the four-lane right-of-way established by NY 890 to the north and follows the Mohawk River (Erie Canal) and CSX Transportation's Selkirk Subdivision rail line southeast toward Schenectady. The first of I-890 passes through mostly undeveloped, wooded areas, a trend that finally ends as the highway curves east to meet the north end of NY 337 at exit 2 near the Rotterdam Square shopping mall. Continuing on, I-890 follows the Mohawk River along the northern edge of General Electric's Schenectady plant, connecting to the facility by way of two separate exits serving different parts of the complex.