Bob, I have the 2020 Escalade ESV with the Z95 magneride. Believe me it gets confusing when you start looking for parts, especially these magneride versions that are no longer produced as as assembly by AC Delco. I landed on Arnott and have no complaints. They have a version for your model (Yukon) and for the extended versions Yukon XL, Escalade ESV, Suburban, etc.
You can get these on RockAuto for a good price. Here's the link to the Arnott page with description. You'd be looking for the MR-3840 if you have the Z95 RPO Code.
https://arnott.mycarparts.com/items/MR-3840
Mine were the MR-4262. I have about 3000 miles on them now. No faults and rides great.
You can see any other notes in my previous post in this forum:
https://www.tahoeyukonforum.com/threads/arnott-mr-4262-install-notes.149741/
Below is a link for a RPO Code decoder I've found useful:
https://decoderpo.com/pages/M.html
Once you locate your RPO Code Sticker in the glove box as Joseph mentioned above, you can decode them there for the plain language correlation. Mine was easy because in the 2018 and up, its a QR code in the door jam.
A piece of advice on these magnerides - Do your homework and know what you're purchasing. There are 1000s of options on eBay that claim to be magneride; however, are not. They have a plug or resistor of some sort that spoofs the computer and the guts of the shock have no magnetic solution.
You have to watch replacing the strut only, because the AC Delco replacement strut does not come with the plug installed. You'll have to transfer the old one over or buy new ones (not expensive). Also there's a sneaky note in the parts diagram about a different retaining nut.