The definition of "old age" is often debated, but many experts agree that individuals who are 65 or older are considered geriatric. Social Security recently increased the age at which individuals can start collecting benefits from 65 years to 67 years, according to Huffington Post.
The reason for the Social Security change, according to Huffington Post, is that Americans are living longer. The definition is still somewhat arbitrary, and according to The Geriatric Patient, the term is defined by health profiles of patients rather than chronological age. More than half of adults who are 65 or older have three or more medical conditions, but there is no age requirement to be treated by a geriatrician.