Can I replace my iPhone home button?

Hi There,

I'm sorry to hear that your home button is not working as expected! You can definitely set up service for your device by going to: https://getsupport.apple.com and selecting your device and answering the trigger questions. Depending on your warranty status there may be a cost for the repair.

If you don't want to set up service online yourself you can also contact Apple Support at the same URL as above and they will be able to provide you your warranty status and what service options are available for you.

You may get away with just a new screen.

Have Apple do it or your touch ID may stop working

https://support.apple.com/iphone/repair/service

or: contact Apple Support 

Anything other than Screen or Battery may be a replacement phone and the price is in the article.

You can see additional service information within the following article:

Prepare your iPhone for packing and shipping

My understanding is that Apple only repairs home buttons with a complete front screen assembly replacement.