Significant events for area code 209
| Date |
Details |
| October 26, 1957 | Area code 916 was split, with 209 covering the southern area. south to the border of 213 |
| Nov. 14, 1998 | Area code 209 was split, with 559 covering the southern area of 209 |
| Nov. 28, 2022 | Area code 209 was overlaid, with 350. |