Food establishments now receive a letter score after an inspection. 

Letter grades are based on a numerical score with a grade of “A” denoting food safety excellence (90 to 100), a letter grade of “B” meaning satisfactory compliance (80 to 89), a letter grade of “C” indicating marginal compliance (70 to 79), and a letter grade of “U” meaning unsatisfactory compliance when an establishment scores 69 or less. 

A follow-up inspection will be conducted when a “C” or “U” grade is earned on a routine inspection with a new score being posted on the follow-up report. If the second inspection score has not improved the establishment's permit to operate may be "pulled". 

A very low routine inspection score may also result in the establishment's permit to operate being "pulled". 
If a restaurant has repeat risk factor violations from previous routine inspections, additional point deductions will be made by the inspector to the overall inspection score.  When a repeat of the same code violation occurs for three (3) consecutive routine inspections, the food establishment can lose its permit to operate.

Giles Roberts, Program Director for the Environmental Health Section of the Georgia DHR, also responded to this question.  His answer:
     "It is not so much as to how low a score can be before the establishment must close.  Both score and the existence of risk factors for foodborne illness triggers the Health Authority to action against an establishment to remove a public health threat. 

     A possible scenario, a food service establishment could have only one item, cooling and out of compliance, with a grade of "A" and refuse to take the necessary corrective action - to discard the food, if the food had not reached 70 degrees F within the first two hours from 135 degrees F.  Since cooling is a risk factor for foodborne illness and the Chapter requires immediate correction of this violation, the Health Authority would be required to seek administrative action to remove the public health threat by forcing closure of the establishment.

     Another scenario, a food service establishments allows a violation of the same code provision of the Chapter to occur for three (3) consecutive routine inspections.  In this case, and at the discretion of the Health Authority, the food service permit may be subject to suspension or revocation. 

     A third scenario would be if a food service establishment received a grade of "U" and did not receive a grade of "C" after 10 days from receiving a grade of "U" on the previous routine inspection.  In this case, the food service establishment person in charge would be asked to voluntarily close the establishment until all violations have been corrected or the Health Authority would take action to suspend or revoke the food service permit.
 
     A four scenario would be if an establishment received a grade of "U" on two consecutive routine inspections.  Again in this scenario, the person in charge of the establishment would be asked by the Health Authority to voluntarily close the establishment until all violations have been corrected or the Health Authority would take enforcement action to suspend or revoke the establishment's food service permit. 

     Finally, the Health Authority can take enforcement action to abate an imminent health hazard, such as the establishment not having a potable water supply due to utility or equipment failure, sewage backup into the establishment, or to stop the continuation of a foodborne illness outbreak during an outbreak investigation."