Common Working File (CWF)

This webpage describes the information available in the national system, known as the Common Working File (CWF), the hours it is available, and the types of inquiries in which the Noridian Interactive Voice Response (IVR) system and the Noridian Medicare Portal rely on the CWF to complete supplier inquiries.

The CWF is comprised of nine localized databases called Hosts. Hosts maintain total Medicare claim history and entitlement information for the beneficiaries in their jurisdiction as updated daily by Medicare contractors and other applicable entities (i.e., Social Security Administration). Each beneficiary is assigned to only one CWF Host site based on where the beneficiary signs up for their SSA benefits. For example, if a beneficiary signs up for their SSA benefits in Portland, Oregon, the Great Western CWF Host will retain the beneficiary Medicare claims and eligibility information. Beneficiaries who permanently move or travel from the state in which they registered for SSA benefits may have their records located within a CWF Host that differs from the state in which their Medicare services are provided.

Noridian uses the CWF to assist with "same or similar" equipment, oxygen rental months, Skilled Nursing Facility and Home Health consolidated billing, Health Maintenance Organization, primary insurance company identification, and other inquiries. When CWF is unavailable, the Customer Service Representatives, IVR, and the Noridian Medicare Portal are unable to assist with these inquiry types.

The identified hours of operation for the nine CWF Host regions are as follows. While the CWF system may be operational or available outside of the timeframes identified below, there are no consistent guarantees for such availability due to routine system maintenance or historical claim purges. When the CWF Host is unavailable for a historical claim purge, suppliers may be notified by their contractor of a CWF "Dark Day."

The tables below show each region of CWF along with which states are in that region and the hours of availability.

Region Northeast Keystone Mid-Atlantic Southeast South
State
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • New York
  • Rhode Island
  • Vermont
  • Delaware
  • New Jersey
  • Pennsylvania
  • Indiana
  • Maryland
  • Ohio
  • Virginia
  • West Virginia

 

  • Alabama
  • Kentucky
  • Mississippi
  • North Carolina
  • South Carolina
  • Tennessee
  • Florida
  • Georgia

Hours Available

5am - 5pm CT M-F
5am - 11am CT Sat

5am - 5pm CT M-F
5am - 11am CT Sat

5am - 5pm CT M-F
5am - 11am CT Sat

5am - 5pm CT M-F
5am - 11am CT Sat

5am - 5pm CT M-F
5am - 11am CT Sat

 

Region Great Lakes Southwest Pacific Great Western
States
  • Illinois
  • Michigan
  • Minnesota
  • Wisconsin
  • Arkansas
  • Colorado
  • Louisiana
  • New Mexico
  • Oklahoma
  • Texas
  • Arizona
  • California
  • Hawaii
  • Nevada
  • Alaska
  • Idaho
  • Iowa
  • Kansas
  • Missouri
  • Montana
  • Nebraska
  • North Dakota
  • Oregon
  • South Dakota
  • Utah
  • Washington
  • Wyoming
Hours Available

6am-6pm CT M-F
6am-12pm Sat

6am-6pm CT M-F
6am-12pm Sat

8am-8pm CT M-F
8am-2pm Sat

8am-8pm CT M-F
8am-2pm Sat

 

Additional information regarding the CWF may found in the CMS Internet Only Manual (IOM), Publication 100-4, Medicare Claims Processing Manual, Chapter 27.

The other systems used by the Noridian IVR and the Noridian Medicare Portal for supplier inquiries are the CMS HIPAA Eligibility Transaction System (HETS) and ViPS Medicare System (VMS).

  • HETS provides beneficiary eligibility coverage information for the IVR and the Noridian Medicare Portal twenty-four hours a day, seven days a week. There is maintenance occurring on many Saturdays as determined by CMS.
  • VMS provides claim-specific, financial, remittance advice, order/referring physician related information between the hours of 6 a.m. to 8 p.m. CT Monday through Friday and between the hours of 7am and 3pm CT on predetermined Saturdays.

Customer Service Representatives are available to assist suppliers with complex inquiries that cannot be answered by the IVR or the Noridian Medicare Portal between the hours of 8:30 a.m. and 5:30 p.m. CT Monday through Friday.

Noridian hopes this CWF informational article assists suppliers in understanding the dependencies our IVR and Noridian Medicare Portal self-service tools have on systems maintained by other entities.

 

Last Updated Fri, 31 Jan 2020 15:07:41 +0000