We are pleased to announce the second Michigan Cosmology Summer School from June 5-9, 2023 at the University of Michigan campus in Ann Arbor, MI. The target participants are graduate students and junior postdocs. Additional details are in the Summer School website: https://johannesulf.github.io/cosmology-school-2023/, including a preliminary list of lecturers. While we expect the majority of participants to be in-person, we will provide a hybrid setup, opening lectures and interaction spaces to online participants. This should significantly broaden the accessibility of the School to junior scientists based in countries from which it is expensive and difficult to travel to the U.S. The school will cover topics across the field of cosmology ranging from theory to experiment, but the emphasis will be on computation and the interface between data and theory. An overarching goal of the school will be to provide participants with concrete practical skills for data modeling. The focus will be on the theoretical underpinnings of inflation, dark matter, and dark energy using modern measurements, principally those coming from the LSS and CMB. The registration opens late January. The Leinweber Center for Theoretical Physics will heavily subsidize registration costs to minimize barriers for attendees. The weather in Michigan that time of the year should be very nice, with long sunny days. We are planning to organize some outdoor activities as well.