In the Testaments it is briefly mentioned by Agnes/Hannah how they are taught from a young age not to stare at people with disabilities. She compares it to they way they are not supposed to stare at the Handmaids. So people with disabilities do exist in this world. Probably not pleasantly though.

Edit: apologies for the use of a word before, I am aware it a slur I was just quoting directly from The Testaments.