For your missing certificate of naturalization, complete form N-565 and send it in with $555 processing fees. Instructions are here: Application for Replacement Naturalization/Citizenship DocumentFor your US passport, report it lost here: Lost or Stolen PassportsYou’ll need to submit a form DS-64 to report the lost passport, along with DS-11 to apply for a new passport. You will need to apply in person and cannot do this via mail. However, you will also need to submit your certificate of naturalization as part of the application. Which means that a) you’ll need to wait for the replacement to arrive, which can take up to 3–6 months; or b) If you need to travel right away, make an appointment with your local passport center/agency and apply in person. You will need to pay the renewal fee ($110), expedited fee ($60), and File Search fee ($150) for not providing the certificate of naturalization.