Based on my search, I found that USCIS cites where to mail forms to lockbox in the **"Where to File" section** of each form's instructions on the official USCIS website. **Key citations found:** 1. **USCIS Lockbox Filing Information Page** - https://www.uscis.gov/forms/filing-guidance/lockbox-filing-information - This page provides official guidance on filing forms with USCIS lockboxes 2. **Form-Specific Instructions** - Each USCIS form (like Form I-130, I-485, etc.) has its own "Where to File" section in the form instructions that specifies the exact lockbox address to mail to 3. **Official DHS/USCIS Documentation** - The DHS Lockbox Tip Sheet (available at www.dhs.gov) states: > "Always check the 'Where to File' section of the form on USCIS' website for the most current information on where to file." **Where to find the specific mailing address:** - Go to the specific form page on USCIS.gov (e.g., uscis.gov/i-130) - Download the form instructions PDF - Look for the "Where to File" section which lists the exact lockbox address based on your form type and state of residence The citation is consistently: **"Check the 'Where to File' section of the form instructions on USCIS.gov for the current lockbox mailing address."**