The vast majority of criminal cases in the United States – both state and federal – are resolved through plea bargaining. Plea bargaining is a process where your lawyer engages with the Assistant United States Attorney to resolve your case without a trial. Before this happens, your lawyer will have carefully reviewed the evidence against you and discussed with you all possible defenses.
If you decide it is in your best interests to enter into plea negotiations, the government may offer you something in return for your waiver of trial (and frequently appeal) and you agree to plead guilty. Generally, what the government offers is a reduction of the penalty you would face if you went to trial and were convicted. Sometimes the government agrees to a dismissal of some of the charges. You are not required to accept a plea bargain or engage in the plea bargaining process. But your lawyer is REQUIRED by the Constitution to inform you of any plea offer made by the government. It is always your decision whether to accept or reject an offer for a plea bargain.
Although the majority of cases are resolved via plea agreement, the government is not required to offer you a plea. If the government refuses to engage in plea negotiations your options are to proceed to trial or enter a guilty plea without an agreement. Your lawyer is the best person to guide you in making these decisions.