I have primary custody of my 4 year old. My husband is in the army & we are about to be moved to a base in another state.My child's father says he can stop me from moving. Is this true?

Have you looked at your divorce papers lately ? That may shed some light on it. Also there was a very much like this one posted within the last 2 weeks I believe. You need to check with a lawyer if your still not sure. If it interferes with his right to see his child he may be able to stop it.

It depends what the custody order says. Being married to someone in the military may be considered an extenuating circumstance. As long as it doesn't substantially interfere with his visitation I don't think a judge will prevent it.

If the child custody paper work ( and most do) state that you can not move out of that area without your ex's permission, yes he can stop you.
Since he has a right to visit and be with his child, the courts normally do not allow the custodial parent to move, esp if the other parents is using his visitation rights.

Often if they do allow it, the parent moving will be responsible for a lot of the costs of getting the child back to visit, and additional time may be allowed to the other parent. Or they can merely refuse to allow you to move. YOu need to get with your attorney.