CMS Pub. 100-05, ch. 5, § 50.1.2

The MSPPAY makes the determination based on the service "thru-date" on the claim to

call one of the following MSP sub-modules to process the payment calculations. All

MSP claims are calculated based on the MSP regulations effective November 13, 1989.

A. MSPPAYB

Calculates payment for Medicare Part B claims. It accepts the limiting charge and the 115

percent limit on fee schedule amounts for nonparticipating physicians for Medicare Part

B claims and calculates payment for Medicare Part B claims by line service.

B. MSPPAYBL

Accepts data from MSPPAY, if the claim is at the aggregate level, and apportions the

primary payer's allowed amount for each service and how much the primary payer paid

for each service based on the ratio computed by the amount billed for each service

divided by the total billed amount. It calls MSPPAYB to calculate the claim by line.

The MSPPAY receives claim data from the A/B MACs (Part B) system and does the

following:

A. Performs validity edits on the sending field THRU-DATE:

• Century value must be "19" or "20."

• Year value must be "00" thru "99."

• Month value must be "01" thru "12."

• Day value must be "01" thru "31."

B. Performs validity edits on the sending field RECORD-ID:

• HMBC = Part B claim; or,

• HMBL = Part B claim by line;

C. Calls the appropriate MSP payment sub-modules:

• MSPPAYB for claim service THRU-DATE with RECORD-ID of HMBC;

or,

• MSPPAYBL for claim service THRU-DATE with RECORD-ID HMBL

D. Returns appropriate status codes along with the Medicare secondary payment

computation and savings data to the A/B MACs (Part B) system. See §50.1.3 for an

explanation of return codes.

Once MSPPAY passes information to the A/B MACs (Part B) claims processing

system, it can be retrieved in any format desired, e.g., savings reports, management

tools, and MSN generation. The reports can be tailored to the A/B MACs (Part B)

specific needs.