My daughter got Sam when he was less than a year old and he is now 38 years old. My Wife and I have been taking care of him for the last 30 years and we are wondering how much longer it's going to go on. Not that we don't like him but how long will this go on. Does anyone with Mustache Parakeet have any experience with this?
This bird has had a good life and has lived longer than expected. The normal lifespan for this type of bird is about 25 years; some longer like yours and some shorter.
It can possibly keep going for another year or two but this is impossible to say for sure. One day you will find it dead in the cage and this will probably be unexpectedly hard for you.
Here is some information about the bird: https://www.thespruce.com/moustached-parakeets-as-pets-390268