Amending Your Petition
If you forgot to include medical debts that existed at the time you filed for bankruptcy, you can amend your Chapter 7 petition to add them, even after your other debts have been discharged. You may not have to do this, however, if your case involved no assets, meaning there was nothing for the trustee to sell, so none of your creditors received anything. In a Chapter 13 case, you don't have to amend your whole petition if you forget to include debts, but only the terms of your repayment plan.
Although you can't discharge debts incurred after you file a Chapter 7 petition, an exception exists with regard to medical bills in Chapter 13 proceedings. If you incur additional medical debt after you file, these bills may be added to your repayment plan. If you add them, you must still pay them in full, plus any interest that accrues during the term of your plan. They're not discharged in the respect that you don't have to pay them, but bankruptcy's automatic stay prevents your creditors from hounding you for payment.