Dearborn-based Oakwood Healthcare System has joined Spectrum Health in Grand Rapids to become Michigan's second health system to post its price and quality measurements. Spectrum, which began posting its prices in fall 2006 on its Web site, will also soon publish average prices paid by Medicaid, Medicare and commercial insurers. In December 2007, the Michigan Health & Hospital Association began an online database that lists charges and payments for 50 common Medicare procedures at 146 nonprofit hospitals in the state.