My father passed June 2010. His 401 showed only 400 dollars after 15+ years employment. This just cannot be right. He moved money often and was very careful about keeping it well hid. His buddies 401 for same length of employment showed 80k plus on their statements. I just know something isn't right. I believe his contributions were going elsewhere. How do I figure it out??

Watch all of his mail for the next year of any statements from other accounts. Check all of his boxes of papers

But he may have taken it out and spent it, many people do that also

If we are referring to a 401(k) account, it is voluntary. So you can't judge by a buddy's account. If you are the executor of your father's estate, you can ask for an accounting from the plan administrator.