Does someone know?

On the application form under where to file: Submit this application to the USCIS District or Sub-Office with jurisdiction over your place of residence.

You can access the form at: www.uscis.gov/n-600

According to the instructions: At a USCIS office or field office with jurisdiction over your place of residence. Here is the locator

https://egov.uscis.gov/crisgwi/go?action=offices

Nevermind

Just wonder why you are filing the n-600?

I have read repeatedly that filing the N-600 remains the best way to evidence citizenship in the long run because passports expire.Its relatively cheap anyway for my children's citizenship to be recorded with USCIS anyway. Its $255 now and will jump to a big amount after next week, so I would rather do it.

Hopefully they are adopted and have been in your physical and legal custody for 2 years. Otherwise they will be denied.

Denied why? If its your biological child and your name is on the birth certificate, why the f would they be denied? You need to read about the Child citizenship Act before making judgements about who will and will not be denied,unles you are an USCIS employee.

Sorry! I thought they were your immigrated stepchildren!
I did the trip for getting my adopted step child that immigrated here her USC!
I do know the CCA VERY well!
Not many people file a n-600 if there kids are native born or biological USCs.

The fact many people dont file does not mean its the right thing to do.Having a document to prove citizenship is very important, instead of having to rely on parents, especially after children grow and are adults.Think about it.Passports can be used, but they expire and they dont seem a very long term way to prove citizenship. I will send the N-600 before the new fees go into effect and have the document for my kids. FYI am a naturalized USC and the biological kids were born abroad.