Glossary
Model Year Code
Position 10 of a VIN. A single character that encodes the model year on a 30-year rolling cycle.
Standard: ISO 3779
Definition
The model year code is a single character at position 10 of a VIN. It cycles every 30 years using the letters A through Y and the digits 1 through 9, skipping the letters I, O, Q, U, and Z (visual confusion) and the digit 0 (reserved). A=1980, B=1981, continuing through Y=2000, then 1=2001 through 9=2009, then A=2010 begins the second cycle. A 2024 model year car carries the letter R; 2025 is S, 2026 is T. Because the cycle repeats, the model year code is ambiguous without context — a VIN with 'B' at position 10 could be a 1981 or a 2011 vehicle. The WMI typically resolves this: a manufacturer that did not exist before 2000 cannot have built a 1981 car.
Why it matters when buying a used car
Sellers occasionally advertise the registration year (when the car was first plated) as the production year. Reading position 10 yourself catches the mismatch — and a car registered the year after it was built sometimes commands a discount.