Any college/ university that I can get admission for MBA with under 20K$ in Washington?

$21,600 is the lowest you can get http://business-schools.startclass.com/l/23/Eastern-Washington-University-WA

[Edited by Duncan on Feb 09, 2018]

That website's info is somewhat faulty, it looks like the $21,600 rate is only for Washington residents:

https://www.ewu.edu/cbpa/programs/master-of-business-administration/pay-for-school/affordable-tuition

... non-residents and international students pay more per credit during most quarters.

If OP is a Washington resident, he/she can do the Western Washington Accelerated MBA for less than $20k:

https://cbe.wwu.edu/mba/mba-costs