For starters, know that you are not alone. One of the most common types of debt is medical debt.
The first step is to send a “validation” letter to the debt collector, via certified mail, within 30 days of receiving a written communication from the collector for the first time. In the validation letter, write that you want validation of the debt and that you want all communications to be in writing. The Fair Debt Collection Practices Act requires debt collections to send you written validation of the debt.
The validation letter serves three purposes. First, it proves that the debt is valid. Second, it buys you time to get organized. Third, it prevents the collector from contacting you again until the collector sends validation. There are strict rules regarding how a debt collector can contact you. The Federal Trade Commission enforces the rules in this area which prohibits debt collectors from using abusive, unfair, or deceptive practices to collect from you. You may even be owed money if a debt collector breaks the rules. Review the Federal Trade Commission rules here and consult with an attorney in your area for debt collection advice.
Assuming the debt is valid, you then want to call the medical bill provider and try to “call the debt” back, meaning that you want to work with the provider instead of the collections agency. Some providers will honor this request, so it is worth a shot. Ultimately, you need to offer some sort of payment which will depend on your financial situation. Know that you can negotiate payments with both the provider and the debt collector, and be sure to get all agreements in writing.