If my social security benefit is $2800 at 65, will my wife also get $1400 if she reaches 65 at the same time? Will our total benefit be $4200/ month, then?

Depends on what you mean by your wife not qualifying for that extra $1,400….either she did or didn’t. If she did then yes you will get that for your total of $4,200/mo or not.

I’m confused as to why you’re thinking your wife might get $1400, if she didn’t qualify for her own social security. Do you mean just because she’s married to you, and you’re both of retirement age? I’ve never heard of such a thing. ....

I’m not sure a wife qualifies without enough work credits, but I believe she will get yours if you are deceased.

You can take less in social security in order to ensure your wife can collect your social security after you die. That is, if she doesn’t have the forty quarters required to receive benefits on her own

The Social Security web site will help you figure it for yourself. You can do this without using any identifying information. It’s quite easy and only takes five minutes.