CMS Pub. 100-16, ch. mc86c18a, § 30.2.1

If a cost report is filed that does not indicate an amount is due CMS, but CMS makes a

final determination that an overpayment exists, interest will accrue beginning with the

date of such final determination. Interest will continue to accrue during periods of

administrative and judicial appeal and until final disposition of the claim.

If a cost report is filed and indicates that an amount is due CMS, interest on the amount

due will accrue from the due date of the cost report unless:

• Full payment on the amount due accompanies the cost report; or

• CMS and the HCPP agree in advance to liquidate the overpayment through a

reduction in interim payments over the next 30-day period.

If CMS determines that additional overpayments exist during the cost settlement process,

interest will accrue from the date of each determination.

The interest rate on each of the final determinations of an overpayment will be the rate of

interest in effect on the date the determination is made.

In the case of a cost report that is not filed on time, interest also will accrue on a

determined overpayment from the day following the due date of the report to the time the

cost report is filed.

If CMS makes a final determination that an underpayment exists, interest to the HCPP

will accrue from the date of notification of the underpayment.