Around age 50, Chiron returns to the place it held when you were born. Because its orbit is about 50 years long, the Chiron return lands for most people somewhere between 49 and 51, and it tends to coincide with a lot of midlife reflection.
Timing your Chiron return
First find your natal Chiron sign and degree with a Chiron sign calculator. Then look ahead in an ephemeris to the years when Chiron reaches that same degree again. Because of the yearly retrograde, it often crosses the exact degree up to three times over about a year, so think of the return as a season rather than a single date.
What people tend to notice
The Chiron return often brings the old theme back into view, but from a different height. Someone with Chiron in the 2nd house who spent years anxious about money may find themselves reassessing what security really means. Someone with Chiron in Gemini may finally write the thing they've been doubting they could write.
For a lot of people it's less of a crisis and more of a recognition: this is the thing I've been working on my whole life, and I'm actually better at it now.
How it fits with other midlife transits
The Chiron return comes shortly after several other well-known midlife transits, including the Uranus opposition and Neptune square, and before the second Saturn return near 58. So it's often part of a longer stretch of rethinking, and it helps not to pin every change on Chiron alone.
Ways to work with it
Look back at what was happening the last few times transiting Chiron made a major aspect to its natal place, such as its first square and its opposition. The ages for those vary a lot from person to person because Chiron's speed changes so much, so check them in an ephemeris rather than guessing. Patterns from those years tend to reappear. Write them down, notice what you already handle differently, and let the return be a review rather than a test.
You can check your natal Chiron alongside the rest of your chart at Astrology Geeks.