It depends on what you did to get the flag as well as the state you are in. Certain types of offenses result in permanent removal from the CNA registry. Sometimes those offenses prevent you from becoming recertified as a nurse aide or becoming a nurse. To find out if you are able to recertify as a CNA or to apply to LPN school it is best to call the Nurse Aide Registry and the Board of Nursing for your state and speak with a representative. Some states publish a list of offenses that automatically disqualify you from ever working in the healthcare field but I can't help you further without knowing the state you are in.