CMS relies on a network of MACs to serve as the primary operational contact between the Medicare FFS program and the health care providers enrolled in the program.

MACs are multi-state, regional contractors responsible for administering both Medicare Part A and Medicare Part B claims.

MACs perform many activities including.

CMS procures all MAC contracts according to the Federal Acquisition Regulation.

Various elements of the Agencys original strategy for implementing Section 911 of the MMA evolved over the years.

The MACs serve more than 1.5 million health care providers enrolled in the Medicare FFS program.

Collectively, the MACs process more than 1.2 billion Medicare FFS claims annually, 218 million Part A claims and more than 1 billion Part B claims, and paid 386 billion in Medicare benefits.

Learn more about the relationships between the MACs and the functional contractors by viewing the diagram of MACs: The Hub of the Medicare FFS Program (PDF) and reading about what the functional contractors do at Functional Contractors Overview December 2019 (PDF).

The first three bytes are termed the OID, which stands for O rganization ID entifier.

By looking at the OID, you can identify the manufacturer of a particular network node.

This means that if you see a MAC address starting with 002000 or 000400, you are looking at a Lexmark device.

Note: Both numbers are based on the canonical form of the MAC address.

The fact that one OID begins with 000400 does NOT indicate that the MSB form is being used.

The last three bytes identify one unique network node within the manufacturer range.

For example: with an Ethernet MAC address of 0020004a6d5e, the OID of 002000 represents Lexmark, and the 4a6d5e represents one unique adapter over the 002000 OID range.

The MAC address of a laser printers network card can be found printed on a network settings page, in a section labeled UAA ( MSB, Canonical ).

The MAC address is presented in two formats, MSB and canonical.

The following is a sample network settings page from an Ethernet internal network card, with the location of the MAC address highlighted in red: The following is a sample network page printed from a Z65n: Note: Since our inkjet printers are Ethernet only, you will see only one MAC address.

Changing the selection will switch all displays of the MAC address between MSB (IBM or most significant bit) and LSB (least significant bit or canonical format).

For example, the following two representations refer to the same MAC address: IBM format MAC Address (MSB) 1 0 0 0 5 A 1 7 5 8 6 9 0001 0000 0000 0000 0101 1010 0001 0111 0101 1000 0110 1001 Canonical MAC Address (LSB) 0 8 0 0 5 A E 8 1 A 9 6 0000 1000 0000 0000 0101 1010 1110 1000 0001 1010 1001 0110 In addition, convention dictates that MSB addresses are formatted for presentation using a colon (:) separator between bytes, while the canonical presentation uses a hyphen (-).

For example, the above address would be presented in MSB format as 10:00:5A:17:58:69 and canonically as 08-00-5A-E8-1A-96.

Mac Address Stands For