Can I trade in my 2016 Macbook Pro to get a refurbished 2018/19 Macbook Pro or does it have to be a brand new Macbook Pro?

I have a 2016 Macbook Pro and I was hoping to trade that in and use whatever Apple says it’s worth to get a refurbished 2018 or 2019 Macbook Pro but I’m not sure if that’s allowed or if the trade ins only work for a brand new Macbook Pro?