For even the fittest, healthiest, and most vibrant among us, the truth is there are inevitable challenges that come from growing older. Major life transitions such as retirement, changes in our physical health, the loss of family or a partner, and changing social roles can lead to feelings of uncertainty, loss of control, and even anxiety and depression. This handbook provides evidence-based skills drawn from cognitive behavioral therapy (CBT) to teach readers the art of flexible thinking, redefine what it means to age, improve mental health, and feel empowered to live life to the fullest-at any age.