There are two types of visas issued for families where a final order of adoption was completed overseas.
The IR3 visa is issued to families where the child is adopted abroad and the parents have seen the child at least once either before or during the adoption process in the foreign country. If you received an IR-3 visa through the country you adopted from, then you will receive your Certificate of Citizenship within 45 days of arriving home. The USCIS is asking that you give them the full 45 days prior to making any inquires. If at that point you haven’t received it, the number to call for the National Customer Service Center through the USCIS is 1-800-375-5283. Please note that some families have received an IR-4 visa due to the fact that only one parent traveled to the country to pick up the child. In this case you will need to readopt in this country and then apply for citizenship for your child.
The IR4 visa is issued to families where the foreign country does not issue final adoptions or the family has come home with a final adoption, but one of the parents has not seen the child either before or during the adoption process. In this case, the family will have to readopt in this country through the state and county where they live and then apply for the Certificate of Citizenship (N-600 form with USCIS).