18 months from DOH. I had a friend who was not awarded a bid because of this during June system bid. The June system bid has an effective date of Jan 29, 2019, but order to be eligible, your seat lock must of been up by the closing date of the system bid. He was hired Mar ‘17, so this is how it could be much longer that 18 months. Say next system baby comes out in January with an effective date sometime in the summer, that means his 18 month seat lock is really over two years, maybe more.