A great place to start to educate yourself on federal requirements/laws is
http://wrightslaw.com/. It is an incredible resource regarding your rights, responsibilities, and how to navigate in the system.
Your child doesn't always have to be "behind". My DD12 has moderate bilateral hearing loss and her speech is behind a tiny bit (take those hearing aids out and she really has trouble with expressive language!). She is a straight A student in grade 6, but has an IEP to ensure that she receives the speech/teacher-of-the-deaf and language resources she needs. For example, phonics are not her strength, to say the least, so spelling on written tests/assignments is not counted against her UNLESS it is a spelling assignment or she has the chance to edit and correct. She also uses an FM system, with the teachers wearing microphones which then send their voices to her hearing aids. We have her on an IEP rather than a 504 plan to ensure that she is doing well.
The Wright's law site has lots of info for beginning the process, managing the process, and helping you fight. Even in good districts you have to show that you know the rules, or they may try and cut corners- budgets are tight everywhere, and even good teachers/administrators cut if they think they can and it won't be noticed.
Good luck navigating the system. The "system" can really suck....but if you look past the system you find good teachers and support staff who are trying their best and have your child's best interest in their heart. Don't let the "system" beat you......its bureaucracy at its best/worst. Remember those caring staff members....they are the ones who get you through the darkest hours. If it were not for exceptional teachers and support staff, my DD12 would NOT be a high-honor roll student, and for their efforts we are eternally grateful.