Supporters of the Affordable Care Act celebrate outside the Supreme Court in 2012, after a divided court upheld the law as constitutional by a 5-to-4 vote. The latest battle, which the Supreme Court hears Wednesday, is over whether people who buy insurance through federally run exchanges are eligible for subsidies. David Goldman/AP hide caption

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Senate Majority Leader Mitch McConnell (from left), Senate Minority Leader Harry Reid and House Speaker John Boehner have reasons to watch the Supreme Court case closely — and to worry about its outcome. Drew Angerer/Getty Images hide caption

itoggle caption Drew Angerer/Getty Images

Uzuri Pease-Greene, right, leads a walk through the public housing complex in the Potrero Hill neighborhood of San Francisco where her family lives. She is working to have the old buildings replaced. Talia Herman for NPR hide caption

itoggle caption Talia Herman for NPR

Abortion-rights opponent Brian Normile of Beavercreek, Ohio, holds up a poster during a prayer vigil outside Planned Parenthood in Washington, D.C., in January. Alex Wong/Getty Images hide caption

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Freedom House paramedics, who first were deployed in the 1960s, provided a crucial service for Pittsburgh residents. The program became a national model for emergency medical transport and care. Courtesy of University of Pittsburgh hide caption

itoggle caption Courtesy of University of Pittsburgh

Chris Newman, seen at her home in Los Molinos, Calif., calls the change she helped get made to lung cancer treatment guidelines a "small, but very important victory." Courtesy of Chris Newman hide caption

itoggle caption Courtesy of Chris Newman

Shopping for an MRI scan? Guroo.org, won't yet show you what your local hospital or radiologist charges, but it will reveal the average cost of the test in your area. iStockphoto hide caption

itoggle caption iStockphoto