Phone: 425-366-2500


Degrees and Certifications:

Master's of Education

Mrs. Kosten

Hello Wonderful Families!


My name is Kelsey Kosten and I have been a teacher at Challenger for 4 years now! I have taught 4th grade from the beginning and love every minute of it!


If you have found this page due to the current school closure due to COVID-19, please follow the link below to access our Google Classroom site. You will need a class code, as well as your student's login information. Please contact me for this code! Our Google Classroom is where you will find all of your student's assignments for the duration of the school closure.


You MUST sign in to google classroom using your Student ID as the start of your email addresss. Please see the example below to help! Forgot your student ID #? Email me and I am happy to help! 

Email Address:


A Little More About Me: I love the PNW and have lived on the West Coast my whole life. I live in Seattle with my husband and our very loved cat Kimbo. When I am not at Challenger, I can be found in the outdoors exploring all the wonderful hikes and parks Washington has to offer. I love cooking, yoga, traveling, and am an avid reader.  Got a recipe or book title you care to share? Please feel free to and I can pass one along as well :)