Abstract: After the discovery of the Higgs boson by the ATLAS and CMS experiments at the Large Hadron Collider (LHC) at CERN in 2012, a new era of studying the properties of this newly discovered particle has begun. Precision measurement of the Higgs boson properties is a golden testbench of the Standard Model and is sensitive to potential new physics. The High Luminosity Large Hadron Collider (HL-LHC), which will increase the dataset by a factor of ten compared to the LHC, offers an unprecedented opportunity to study the Higgs boson. Higgs boson physics prospects at the HL-LHC thus serves as a crucial reference point for the planning of future high energy physics experiments in general. In this seminar, I will present recent highlights of Higgs boson physics results from the CMS experiment using the LHC Run 2 data and introduce CMS experiment’s goal to contribute to Snowmass 2021, focusing on the Higgs boson physics prospects at the HL-LHC.