Unfortunately, there probably isn't much you can do once you've agreed to the settlement amount.
If you would like a free consultation, call me at 702-823-3333. www.naimidilbeck.com
My colleagues are correct -- once you have signed a settlement agreement and release, there is no way to get more money from the person or entity who caused the injury. HOWEVER, if you have not yet signed a distribution agreement with your attorney (and it sounds like that may be the case if medical bills are still being negotiated), then you can certainly attempt to negotiate something with your attorney and/or your medical providers to put more money in your pocket.
Responses are for general information purposes only, and are based on the extremely limited facts given. A consultation with an attorney experienced in the area of law(s) indicated in the question is highly recommended. Information and advice given here should not be relied upon for any final action or decision, as the information is limited by its nature to the question asked and the fact(s) presented in that question. THIS RESPONSE DOES NOT CREATE AN ATTORNEY/CLIENT RELATIONSHIP, particularly considering that the names of the parties are unknown.
A roundup of the best tips and legal advice.