My 92-year-old grandfather cuts hay atop a 5-ton tractor each summer, baling winter feed for more than 800 head of cattle. The rest of the year he herds, corrals, immunizes, and cares for the cattle. A senior scientist at the Centers for Disease Control and Prevention (CDC) reported to work each day well into his 80s, contributing greatly to our understanding of biomarkers, and helping advance laboratory safety measures. An annual laboratory safety award is now given each year in his honor. How old is too old when it comes to work? No simple answer will suffice. Not many of your patients will bale hay in their 90s or create new science well into the ninth decade of life, but some will choose to, or must, work long after they originally planned to retire. Some must stand for long periods on the job. Others must bend, reach, and lift. Some clinicians will see patients well after the "traditional" retirement age has passed. It is a near certainty that healthcare professionals will see many older workers and should do all they can to support and enhance the ability of these individuals to continue to work. Many workers benefit significantly from continuing to work into old age. Work is "medicine" -- even better than medicine for many. In addition to providing economic security and often wider access to healthcare options, work enhances well-being, promotes social interaction, increases the variety and quality of life, and provides many people with a sense of accomplishment and achievement. Although some older individuals work out of necessity, many report that they continue to work to contribute, or to "make a difference." Almost all jobs help older people sustain and extend their physical activity level and support increased social engagement and larger support networks. Work provides accountability for many; an absence from work may serve as the first sign to warn distant family that something is wrong with a loved one. Emerging evidence also suggests that work may improve brain health, sustain healthy cognition, and protect memory. Unfortunately, not everyone is able to continue to work as they age. People with physically demanding jobs, where they must work at or near full physical capacity, are often forced to leave employment or change to related but less taxing work. Some physically arduous jobs can lead to, or serve as a cofactor in, the development of long-term disability. Increasingly, the burden of chronic disease in younger and younger workers will shorten their careers. Obesity, tobacco use, physical inactivity, and poor nutrition give way to early hypertension, diabetes, hyperlipidemia, sleep apnea, and joint decline. Given the importance of work in terms of economic security, life options, and health, early identification of disease precursors and optimal management of chronic disease with an emphasis on sustained functional ability is paramount.