A key part of President Barack Obama’s signature health care reform is set to take effect Oct. 1. That day, Americans around the country will be able to access online marketplaces and compare shop health plans online. But in many jurisdictions, including the Washington region, the rollout may be complicated. While Maryland has been one of the most aggressive states in crafting its own health care exchanges, the state of Virginia has deferred entirely to federally-run exchanges. Meanwhile, the District-run exchange has hit a technical roadblock and may not be fully functional by the Tuesday deadline. Health care experts from around the region explain the local impact of the health care rollout.