Yes, if you move, you need to notify the IRS of your new address. The IRS needs to change their records so that any tax refunds due to you or any other IRS communications will reach you in a timely manner. If you filed a joint return, you should provide the same information and signatures for both spouses. If you filed a joint return and you and/or your spouse have since established separate residences, you both should notify the IRS of your new addresses.