No. The CMMI Institute does not provide a certificate at the conclusion of an appraisal. The CMMI Institute will provide an appraisal mark image (sometimes referred to as a "CMMI logo") to the appraised company along with instructions for the use of the mark and the language that can be used to describe an appraisal.
Any appraised organization receives an Appraisal Disclosure Statement (ADS) and a Final Findings Report from their lead appraiser. These forms not only document the achieved maturity level or capability level profile, but also document which parts of the organization were appraised. These reports are owned by the sponsoring organization and lead appraiser. They do not come from the CMMI Institute.
Certificates, per se, are not provided by the CMMI Institute at the conclusion of any appraisal. Many lead appraisers provide something of this nature, but that would come from them and not from the CMMI Institute.