It’s easy to forget that before 1966, roughly half of all American seniors were uninsured, living in fear that the high cost of health care could plunge not only them, but their families, into poverty. Few of us remember that not long ago, far too many disabled people, families with children, pregnant women, and low-income working Americans were unable to afford the medical care they needed to stay healthy and productive.

Fifty years ago, on July 30, 1965, the landscape of health care in America changed forever when President Lyndon B. Johnson signed the landmark amendment to the Social Security Act that gave life to the Medicare and Medicaid programs.

Medicare and Medicaid save lives, help people live longer, and provide the peace of mind that comes with affordable health care that’s there when you need it. Chances are, you or someone in your family either has Medicare or Medicaid or you know someone who does. In fact, Medicare and Medicaid cover nearly 1 out of every 3 Americans — that’s well over 100 million people.

Marking the 50th anniversary of these lifesaving programs this summer gives us an important opportunity to recognize and remember the ways these programs transformed the delivery of health care in the United States.

Fifty years later, no other program has changed the lives of Americans more than Medicare and Medicaid.

Today, about 55 million Americans depend on Medicare to cover 23 types of preventive services, including flu shots and diabetes screenings (some of these services are free; for others you have a deductible and a small copayment.) Medicare also covers hospital stays, doctor bills, lab tests, supplies like wheelchairs and walkers, and prescription drugs.

Medicaid provides comprehensive coverage to more than 70 million eligible children, pregnant women, low-income adults and people living with disabilities. It covers essential services like annual check-ups, care for new and expecting mothers, and dental care for kids from low-income families.

Medicare and Medicaid provide more and more Americans with access to the quality and affordable health care they need and deserve to live happy, healthy, and productive lives. Though they started as basic health programs for people who had no other access to health coverage, Medicare and Medicaid have helped millions get access to care they wouldn’t get otherwise.

Over the course of five decades, Medicare and Medicaid have become the standard bearers for coverage, quality, and innovation in American health care.

Innovative and dedicated teams are combating fraud and working to continually improve the quality of life and care delivered under these programs. Medicare and Medicaid are among the most efficient and well-managed health insurance programs in the world. They will continue to transform to create a health care system that delivers better care, spends health care dollars more wisely, and results in healthier people.

President Johnson would be heartened to know that the hard-fought efforts to improve our health care system have not only succeeded, but that America is on track to give even better access, higher quality care, and improved health for the next 50 years and beyond.

How has Medicare or Medicaid (or both) helped your life or that of someone you care about? Whether you’ve just enrolled or have been covered for decades, we’d love to hear from you. You can share your Medicare or Medicaid story through our Medicare.gov website, or connect with us on Twitter or our just-launched Facebook page.

David Sayen is Medicare’s regional administrator for Arizona, California, Hawaii, Nevada and the Pacific Territories. You can always get answers to your Medicare questions by calling 1-800-MEDICARE (1-800-633-4227).