The form G-28 is known as the Notice of Entry of Appearance as Attorney or Accredited Representative. It is an immigration form that is used for the sole purpose of notifying the USCIS that an attorney, accredited representative or law student working under the supervision of an attorney, is handling the case of an applicant for immigration relief or benefit.
When you sign a form G-28, you are authorizing that attorney or accredited representative access to your confidential immigration files. You are also authorizing them to send and receive correspondence from the USCIS on your behalf.
Having a filed form G-28 is advantageous in that your attorney is immediately able to address the significance of any correspondence received from the USCIS. Furthermore, it allows your attorney to serve as a back-up recipient of mail received from the USCIS should you fail to properly notify USCIS of a new address or should the USCIS inadvertently send mail to an old address.
There is no charge associated with submitting a form G-28.