16歲才行，15歲不可以

Applying for a Passport as a 16-17 Year Old (state.gov)

If you have your own current identification document (ID), you may apply for a passport if you are age 16 or 17. You must show at least one legal parent or legal guardian is aware that you are applying for a passport. For more information, please see Children's Passport Issuance Alert Program.

How to Show Parental Awareness:

• A legal parent or legal guardian appearing with you in person when you apply for your passport. The agent or employee accepting the application will ask your legal parent or legal guardian to sign Form DS-11. Bring a photocopy of that parent or guardian's ID.
• Submit a signed note from your legal parent or legal guardian with a photocopy of their ID.
• Submit proof that your legal parent or legal guardian is paying your application fees (Example: parent or guardian name is written on  the check or money order).
• We may ask you to submit a notarized statement from your legal parent or legal guardian (e.g., on Form DS-3053) which states he or she supports you receiving a passport. The statement must be accompanied by a photocopy of that parent or guardian's ID.