The impetus for the lawsuit was the elimination last year of the individual mandate penalty as part of the Trump administration's tax reform overhaul. (Photo: Shutterstock)

March 23 marks the ninth anniversary of the passage of the ACA, the Obama administration's landmark health care reform bill. A lot has happened during that time, and it's been a controversial ride. While the ACA is credited with opening access to health insurance to more than 20 million Americans who would otherwise have gone without, critics also blame it for increased health insurance costs and limiting health care consumer freedom.

Nine years later, the law itself also looks a bit different from its debut, facing a laundry list of lawsuits seeking both to challenge its constitutionality and defending its core principles against executive orders and actions taken by the current administration.

Take a look at the key developments and changes to the landmark health care law under the Trump administration.