This report from The Commonwealth Fund delves into the pre-existing condition insurance plans created by the ACA.  

From the executive summary:  

The Patient Protection and Affordable Care Act includes a provision for the establishment of a temporary high-risk pool, also called the Pre-Existing Condition Insurance Plan (PCIP), to quickly make health insurance available to uninsured individuals with preexisting conditions, many of whom previously had been denied coverage. Twenty-seven states elected to administer the PCIPs for their citizens, while the remaining states and the District of Columbia chose to let their PCIPs be federally administered. This issue brief examines eligibility, benefits, premiums, cost-sharing, and oversight of the PCIP programs, as well as variation of the plans from state to state. The PCIPs will run through December 31, 2013, at which time participants will be transitioned to exchange coverage.

Full Report: Pre-Existing Condition Insurance Plans Created by the Affordable Care Act of 2010 (PDF | 934 KB)  

The Commonwealth Fund. (2010). Pre-Existing Condition Insurance Plans Created by the Affordable Care Act of 2010. Hall, Jean P. and Moore, Janice.