Retired?  That word or idea is not biblical.  Elders are commanded to teach and we want to put the old in confinement (old folks homes).

Do you know someone looking for a missions opportunity for teachers? The Mission Society’s K through 12 school in Bolivia is looking for volunteer Christian teachers starting this fall. The surrounding community ranges from indigenous spiritual practices to atheism and materialism. Len Phillips with The Mission Society says the school is their ministry tool. “We really see the school as just a tremendous bridge into the Bolivian culture and society, and a great avenue for sharing the transforming power of Jesus Christ with our students and families.” You don’t have to speak Spanish to get involved. The only requirement is that you love teaching kids and have a heart for the Lord. Even if you can’t volunteer, your prayers are needed “for the spiritual atmosphere on our campus: that the Lord would be at work, and that He would continue to be opening up hearts and lives, just giving that spiritual vitality even to our teachers and staff as they minister to our students.”

http://www.bobbywatts.org/index.html