The U.S. Supreme Court's decision to uphold the Affordable Care Act marks a giant step forward for millions of Texas children and families who can now get the healthcare coverage they need.Because of our state's highest-in-the-nation rates of uninsured, Texas stands to benefit from this decision more than any other state.The nation's health law has already improved the lives of millions of Texans. More than 7.5 million Texans, including more than 3 million children, have directly benefited from the law since 2010.The law also helps protect healthcare for over 3 million Texas children who rely on the cost-effective Medicaid and Children's Health Insurance Program for coverage.Let's agree that when we create opportunities for children to get the care they need, when they need it, more children stay healthy and do better in school. Parents have peace of mind and a sense of security about their loved ones' health.And communities are better off, with less crowding of emergency rooms, when care is accessible in less expensive settings.By 2014, more middle-income Texans of all ages will benefit because insurance companies will no longer be able to engage in practices that prevent people who really need care from getting it.In addition to children who've gained this already, adults too will no longer be denied care for pre-existing conditions nor have arbitrary limits placed on their care.Insurance companies will have to play by the rules and refund money to people they've overcharged.Busy families will find more affordable and comprehensive private coverage options through the creation of an organized and competitive healthcare marketplace called an "exchange."While this ruling is cause for celebration, it's also a call for action. Now that the law's legality has been affirmed, our state leaders must get to work on implementing the law effectively for all Texans. Here are some important first steps:Texas must accept the unprecedented opportunity to cover the millions of uninsured and underinsured among us through Medicaid at no cost to the state for the next three years, and at only 10 percent of the cost thereafter.By comparison, this represents a mere fraction of the cost of care that our hospitals today absorb for the uninsured. Our families deserve the same opportunities as those in other states to get the care they need.Establish an exchange that's designed by Texans, especially for Texans.This will help many of our state's over 6 million currently uninsured residents and thousands of small businesses to find and compare insurance options so they can get great coverage at a great price.As we celebrate the court's decision, we recognize the hard work needed to ensure the law works as intended for Texans of all ages, abilities and income levels.We look to build upon the enormous progress for children's healthcare under the law and will work until every Texan is guaranteed access to comprehensive, affordable healthcare.Anne Dunkelberg is associate director of the Center for Public Policy Priorities. Eileen Garcia is chief executive officer of Texans Care for Children. Dr. Laura Guerra-Cardus is associate director and policy director of Children's Defense Fund-Texas.