My 2018 Silverado is out of warranty.The dealer said that the starters were on backorder,but I was able to locate one on my own.I asked for a quote on labor to install it,and my local Chevy dealer said they could do the job for $288.
I thought that seemed rather expensive.Upon installing it myself,I found that you can easily get the old starter down in less than 10 minutes and be complete with the job in about 1/2 hour.
So if you need a starter and are out of warranty,don't get ripped off by your local Chevy dealer.
So far so good with the new starter.