- Section 1 Introduction
- Introduction
- Federal Government Administration
- Fundamentals of Medicare: State Responsibilities
- Fundamentals of Medicare: Participating Providers
- Voluntary and Involuntary Termination of Provider Agreement
- Disclosure of Health Insurance Information
- Privacy Act
- National Provider Identifier
- Legacy Provider Numbers/Provider Transaction Access Numbers (PTANs)
- Medicare Administrative Contractors
- Fundamentals of Medicare: Information References
- Acronyms
- Fundamentals of Medicare: Glossary of Terms
- Section 2 Medicare Basics
- The History of Medicare
- What Is the Medicare Program and How Is It Funded?
- Medicare Eligibility and Premiums
- The Social Security Administration and Medicare Enrollment
- The Medicare Card
- Medicare Part A
- Inpatient Hospital Care
- Skilled Nursing Facility Inpatient Care
- Home Health Care Benefit
- The Hospice Benefit
- Medicare Part B Medical Insurance
- Fundamentals of Medicare - Medicare Program Exclusions
- Medicare Advantage Organizations
- Medicare Secondary Payer
- Supplemental Insurance
- Coordination of Benefits Trading Partners
- Section 3 Fraud and Abuse
- Section 4 Getting Ready to Bill Medicare
Section 4: Getting Ready to Bill Medicare
Common Working File
The CWF was developed in 1989 as a means to maintain all of the records for each Medicare beneficiary. These records are a detailed account of each Medicare beneficiary’s status and the services that he/she has received. Some of the information documented in CWF follows:
- Entitlement to Medicare Part A and Medicare Part B
- Date of birth and date of death
- Part A and Part B blood deductible information
- Benefit periods and days remaining in the current benefit period
- Beneficiary claim history
- Hospice and/or MAO plan enrollment
- Primary payer insurance coverage when Medicare is not primary
- Preventive services
With over 52 million Medicare beneficiaries, it is impractical to store all of the records in one place. Therefore, nine different host regions manage the information. The assigned region is determined by the primary residence of the beneficiary at the time that he/she becomes eligible for Medicare. However, a beneficiary may receive services anywhere in the United States or its territories, and these records will be posted to CWF.
Regardless of where services are rendered, the provider may access these records via claims processing or the information inquiry function through their MAC.
CWF should be checked prior to submitting a claim to ensure that the beneficiary has Medicare Part A and Medicare Part Bas well as to ensure that Medicare is the primary payer among other helpful information. Providers find that by checking CWF before the claim is submitted to Medicare, the provider avoids unnecessary claim rejections.
Please note: Access to CWF via HIQA will soon be terminated. Providers will have to check eligibility using HETS, NGSConnex or the IVR application. Additional information on HETS can be found on the CMS website.
Revised 1/2021