Reminder: Ambulatory surgery facility audit process

Blue Cross Blue Shield of Michigan regularly conducts post-payment utilization review audits at ambulatory surgery facilities. During these audits, we review medical records and billing information to ensure that billed and paid services were ordered, rendered, medically necessary, documented, reported and covered under the patient’s contract according to Blue Cross guidelines.

When a facility is selected for audit, we obtain an audit sample that represents the patient population. The methodology we use for ASF audits is random sampling. The process places an equal probability of selection on every patient at a facility within a specific time frame. A computer selects the patients to be used in the audit.

The size of the audit sample is determined by two quantities: confidence and precision. These values determine the risk level associated with the sample estimates deviating from the true unknown population overpayment.

The acceptable values are 95 percent for confidence and 10 percent for precision. This means that Blue Cross wants to be 95 percent confident that the sample compliance error rate isn’t different from the population compliance error rate by more than 10 percent. This produces a sample size large enough that the estimates obtained through the audit accurately represent characteristics of the population.

After we have selected the audit sample, we’ll conduct an on-site audit at the facility or at a Blue Cross office. Once the auditor completes the review of the medical record and billing information, we’ll identify any overpayments due to billing errors and medical necessity determinations and then recover the payments. Any underpayments we identify will be offset against the overpayments. If there are no overpayments, we’ll instruct the facility to re-bill underpaid claims to Blue Cross. We’ll then send a detailed audit report to the facility.

Facilities can appeal the audit results. If the facility chooses to appeal, we’ll provide information for the next available level of appeal.

For more information, refer to the provider manual for ambulatory surgery facilities on web-DENIS.