If parents are aging but in good health, I've found a good way to broach this topic is to do it as part of a project where it's not just the aging family member

If parents are aging but in good health, I've found a good way to broach this topic is to do it as part of a project where it's not just the aging family member who is being interviewed. Then you also get the bonus of having archives of interviews with the rest of the family.