Q: What is the difference between BENE_ID and Health Insurance Claim (HIC) number?  (FAQ001)

A: The difference between BENE_ID and Claim (HIC) number is as follows:

  • The BENE_ID is a unique beneficiary identifier encrypted specifically to the researcher/Data Use Agreement (DUA). This identifier is unique to the Chronic Condition Data Warehouse (CCW) and protects the identity of the Medicare beneficiary.
  • NOTE: There may be multiple HICs per BENE_ID due to the following reasons:
    • Beneficiary Identity Codes (BICs) change in the source Medicare eligibility files due to change in or clarification of the relationship to the covered beneficiary. When the BIC changes, the HIC changes.
  • There may also be multiple BENE_IDs per HIC due to a change in gender or Date of Birth (DOB) in the CCW monthly enrollment updates.

Q: How do I use identifier crosswalks to link data?  (FAQ002)

A: Your request may include one or more identifier crosswalks that will allow you to link datasets. These identifier crosswalks may include any of the following identifiers, depending on your data use agreement (DUA):

  • BENE_ID (contained in the CCW data)
  • BID, or beneficiary identification (contained in the CCW data received from Acumen – prior to January 2009)
  • SSN (social security number)
  • HIC (health insurance claim number)
  • RES_ID (resident identification number from assessment data)

Q: When using the Drug Characteristics file, would Brand Name (BN) equal Generic Name (GNN) if the drug was dispensed as generic?  (FAQ003)

A: If the GNN is the same as BN, it is a generic product. However, this does not cover all the generic products. Many generic products have their own BN.

The Food and Drug Administration (FDA) maintains the Orange Book, which lists the approved generic products. For more information, see for more details. If Reference List Drug (RLD) is No, then the drug product is considered a generic product. If the RLD is Yes, then it is called an innovator drug (or the brand product as considered by most) and it is the standard by which the generic products are tested.

Q: How do researchers, who are using CCW data, open a File Transfer Summary (.FTS) document?  (FAQ004)

A: Open the .FTS document in Notepad (it is a plain text document). Open the .SAS program with Notepad (if you don't have SAS). If you are using STATA, use the .FTS for layout to read in the .dat file (Microsoft prompts to open in Word, changes the font automatically; don't save changes).

Q: How is the CCW BENE_ID assigned?  (FAQ005)

A: The BENE_ID assignment is based on an extensive beneficiary matching logic routine which is updated monthly from CMS Medicare Enrollment Database (EDB) data feeds. This data source is more timely than other CMS data sources (conflict with other CMS data sources may occur in a small number of cases). One BENE_ID can map to multiple health insurance claims (HICs) due to changes in HIC, etc. In order to be assigned a BENE_ID in the CCW, the matching logic must reach a predetermined confidence interval, based on CMS specifications.

CMS Virtual Research Data Center

Q: What is the CMS VRDC?  (FAQ006)

A: The CMS VRDC is an alternative solution for accessing and analyzing CMS data for research purposes. Historically, CMS has provided data to researchers by preparing and shipping encrypted data files on external media. The VRDC allows researchers to access and perform their own analysis and manipulation of CMS data virtually from their own workstation. The VRDC provides researchers with a secure mechanism to access timelier data in a more efficient and cost-effective manner.

Q: Who can get access to CMS data using the Virtual Research Data Center (VRDC)?  (FAQ007)

A: The VRDC is a mechanism for approved researchers to access CMS data. To learn more about requesting access to the VRDC, please refer to the Requesting VRDC Access section of this website.  Users may also learn more about getting data for research by visiting the ResDAC website at  NOTE: Researchers interested in using the VRDC to access CMS data will follow a very similar approval process as those who request physical data provision.

Q: Why can't everyone receive access to CMS data via the Virtual Research Data Center (VRDC)?  (FAQ008)

A: The data in the VRDC is protected health information and CMS must comply with all federal laws and regulations governing the release of data, most notably, the Health Insurance Portability and Accountability Act (HIPAA). In addition, as stewards of the data, CMS has a responsibility to carefully protect this sensitive information.

Q: Can I still get data shipped to me to conduct research?  (FAQ009)

A: Yes. Researchers now have two options for accessing data: 1) physical delivery of encrypted data files on external media or 2) virtual access via the Virtual Research Data Center (VRDC). In many instances, the cost of accessing data within the VRDC will be much more affordable than receiving data on portable media. Researchers cannot request shipment of data files they are accessing in the VRDC.

Q: Why is the CMS Virtual Research Data Center (VRDC) a more secure mechanism to share data with researchers?  (FAQ010)

A: Under the VRDC model, beneficiary identifiable information never leaves the CMS environment. Researchers will be assigned a dedicated workspace within the VRDC that will contain the data they need for their project(s). They will be allowed to upload external files to the workspace and then conduct analyses using the CMS data as well as any data they upload. However, researchers are only allowed to download non-identifiable analytic output to their independent workstations. They will be required to request an output review for any analytic files they wish to download and CMS will conduct a review of the output to check for protected health information, personally identifiable information, or small cells which could be used to deduce the identity of an individual.

Q: What data can be accessed within the CMS VRDC?  (FAQ011)

A: Descriptions of the available data files can be found on the Research Data Assistance Center (ResDAC) website at Data dictionaries can be found at Additionally, users can upload their own data into the VRDC to analyze with the CMS data. Researchers can request access to quarterly FFS claims data and the most current version of the Master Beneficiary Summary File.

Q: What data analysis tools are available to researchers in the CMS VRDC?  (FAQ012)

A: SAS is the main data analysis tool in the CMS VRDC. The current version of SAS available is 9.4. Users are not able to upgrade to versions of SAS for which they have internal licenses. In addition, researchers will have access to the Microsoft suite.

Q: Is training available on the CMS VRDC?  (FAQ013)

A: Yes. Several CMS VRDC training classes are available on the public website (, while other on-line classroom training is available in the secure CCW website and can be accessed once a user receives their CCW user ID and password.

Q: Why must users go through Remote Identity Proofing (RIDP), including providing personal and credit information, prior to obtaining a CCW User ID to access the CCW Virtual Research Data Center (VRDC)?   (FAQ027)

A: Identity proofing is implemented to obtain a CCW User ID because CMS must comply with the Federal Information Security Management Act (FISMA) and National Institute of Standards and Technology (NIST) requirements. CMS is following OMB Memorandum 04-04 (dated December 16, 2003) which requires ALL federal systems that are accessed electronically to utilize identity-proofing. Experian Precise ID℠ is a third party system that is owned and operated by Experian. CMS contracted with Experian to provide the highest probability that the person accessing government systems is who they say they are; CMS does not receive or store your verification data. The information sent to and from Experian is transmitted securely using strong encryption.

Q: What are the basic user requirements necessary for accessing the CCW VRDC? (FAQ028)

A: Users will need to have the requisite knowledge/skill sets to obtain access as a standard/basic CCW VRDC user – using SAS environment including:

  • Discuss internal IT/security policies within your organization to ensure there are no firewall/security or administrative rights issues that may require involvement from your IT department prior to installation/updates. All CCW VRDC users must reside in the United States and must only connect to the CCW VRDC from an IP address registered for use in the United States.
  • Working knowledge/experience with SAS or Stata programming language
  • Meet CCW security requirements (including annual security training)
  • SAS Enterprise Guide (EG) — SAS EG user guides available on secure CCW website
  • Register as a participant for My LMS
  • Review of training on secure My CCW > File Transfers page >SSecurSSeS 
  • HIPAA Compliance
    • To protect the confidentiality of Medicare and Medicaid beneficiaries, unless authorized by CMS OEDA, CCW performs data output review prior to release from the CCW VRDC
    • Avoids disclosure or perceived disclosure of confidential information:
      • Protected Health Information (PHI)
      • Personally Identifiable Information (PII)
      • Small cell sizes
      • Comply with output review guidelines based on CCW VRDC access approved by CMS

Q: What are the general system requirements for accessing the CCW Virtual Research Data Center (VRDC)? (FAQ029)

A: CCW access:

  • Discuss internal IT/security policies within your organization to ensure there are no firewall/security or administrative rights issues that may require involvement from your IT department prior to installation/updates. All CCW VRDC users must reside in the United States and must only connect to the CCW VRDC from an IP address registered for use in the United States.
  • VRDC currently supports Windows 10; does not support MAC
  • Ensure your system is continuously updated to meet CMS standards  
  • Must have VMware Horizon Client 5 and latest version is recommended
  • Multi-factor authentication (MFA) — you will need to enroll an Okta factor
  • Google Chrome, Mozilla Firefox or Microsoft Edge (latest version recommended)
  • Adequate free local disk space to install VMware Horizon Client and file downloads (if applicable)
  • VMware Horizon Keyboard Shortcuts not within the FAQs
    • New Server command Alt+N
    • Display Options menu Alt+O
    • Open the help system in a browser window Alt+O+H, Ctrl+H
    • Display the Support Information window Alt+O+S
    • Display the About Horizon Client window Alt+O+V
    • Display Settings menu Alt+S, Shift+F10+S
    • Full list of shortcuts

Q: Will users be able to upload external files to the CCW VRDC? (FAQ030)

A: Yes. Users may upload finder files through the Secure File Transfer System (SFTS) for their requested cohort and external files for utilization in their analysis.

  • Users are responsible for assuring that any non-public data being uploaded into the VRDC environment is not proprietary or restricted by a license agreement. If data are restricted and the researcher obtains approval to upload the data, the approval must be provided with the DUA data request package
  • Users will need to attest to approval for data files prior to uploading to the VRDC
  • Finder files may include SSN, Date of Birth (DOB), or gender, which provide better linkage to CCW data
  • Uploaded files are subject to review to ensure they are virus free
  • Due to unknown factors such as internet connection and PC speed, it is recommended that uploaded files be limited to five (5) Gigabytes (GB)

Q: Can I upload my own software into the VRDC?  (FAQ031)

A: No, external software cannot be uploaded by users. CCW VRDC Standard desktops include basic software available to all CCW VRDC users.

Cloud Environment

General Questions

Q: What CCW VRDC services have threshold limits and what are they? (FAQ080)

A: Two CCW VRDC Cloud Environment services will have threshold limits as of March 27, 2022. These services include space and Databricks credit usage. The Centers for Medicare & Medicaid Services (CMS) is increasing annual space allocation to 2 terabytes (TB) per DUA for researchers and 5 TB per DUA for innovators. The second threshold limit is for Databricks users. Databricks measures usage in ‘credit’ consumption, and each project (DUA) comes with an annual allocation of 2,000 credits for researchers and 4,000 credits for innovators. For each tool — space and Databrick credit usage — the CCW VRDC system emails alerts to you and your DUA project team at 75%, 90%, and 100% of the DUA allocations.

Q: What is the difference between the DUA project fee per year for SAS only and full CCW VRDC options? (FAQ081)

A: The DUA project fee for SAS only option covers all the same services and access as a full CCW VRDC option except for Databricks. For more details, reference the ResDAC fee list.

Q: How do licenses for Stata apply with the new fee structure? (FAQ082)

A: CMS continues to apply Stata licenses at a user level. For more details, reference the ResDAC fee list.

Q: When there are additional quarters of data released, does the DUA amendment involve a fee? If so, what is the amount or which fee applies? (FAQ083)

A: CMS has changed the quarterly data fee from a yearly renewal to a one-time fee. If a quarterly fee has been paid on a DUA in the past, the DUA will not be subject to an additional quarterly fee. Updates to add new years of quarterly data will be $0 charge. Please contact ResDAC to initiate this request.

Q: When do I need to pay for an additional dataset? (FAQ084)

A: You pay a fee for a data extract if your cohort criteria changes from the original data request or you are adding a new file not previously extracted.

Databricks Analytic Tool and Allocations

Q: What does the Databricks tool offer? (FAQ050)

A: For users wanting additional analytic tools beyond SAS Enterprise Guide (SAS EG), the full CCW VRDC option includes Databricks. Databricks is a data analytic platform allowing you to write Structured Query Language (SQL) code in a Databricks notebook using the %sql commands. The “Notebooks” concept in Databricks is like a SAS EG project, including support for multiple languages like R and Python.

Q: What is a Databricks credit and what would I use it for? (FAQ051)

A: A Databricks credit, also known as Databricks Unit (DBU), is a normalized unit of processing power on the Databricks Platform used for measurement and pricing purposes. Processing metrics drive the number of DBUs a workload consumes, which may include the compute resources used and the amount of data processed. For example, 1 DBU is the equivalent of Databricks running on a standard i3.xlarge machine with the Databricks 8.1 standard runtime for an hour. When a standard cluster is up and running, it uses 5 DBUs per hour.

Q: How will I know what my current space or Databricks credit usage is? (FAQ052)

A: After March 27, 2022, you will be able to access the CCW VRDC User Dashboard application. This will replace any monthly space reports you previously received from the CCW team. The dashboard will display your current DUA SAS space and Databricks credit usage. You will have an at-a-glance view to refer to your DUA’s threshold limits. The CCW team will refresh the dashboard daily. Look for additional details on understanding your usage on the dashboard “Help” icon.

Q: What if I do not need Databricks? (FAQ053)

A: For users that perform analysis within SAS EG and do not need to use Databricks, a SAS only option is available at a lower fee. The SAS only project fee would include the following:

  • ResDAC support
  • Data extract processing
  • Allocated amount of space
  • Allocated number of output reviews

Q: What should I do if I get a threshold alert for my DUA’s Databricks credit usage? (FAQ054)

A: The CCW VRDC system alerts to you and your DUA project team at 75%, 90%, and 100% of the DUA allocations. If you receive a threshold alert for the consumption of Databricks credits, you and your project team will need to determine whether to contact ResDAC to buy more credits.

Q: What happens if I reach my maximum Databricks credit usage threshold and what should I do? (FAQ055)

A: When a DUA reaches 100% of the allocated Databricks credits, all users within this DUA will no longer be able to use Databricks. To increase your CCW VRDC Databricks credit limit, you must contact ResDAC to purchase additional Databricks credits.

Q: If we reach our Databricks credit threshold for a DUA, how long will it take us to pay for more credits and get our access back? (FAQ056)

A: You will need to go to ResDAC to request a cost estimate for additional Databricks credits. Once ResDAC processes the cost estimate and CMS confirms payment, the CCW team will apply your new credit allotment to the DUA. NOTE: This does not require a DUA amendment.

Space Allocations and Thresholds

Q: What should I do if I get a threshold alert for my DUA’s space usage? (FAQ060)

A: The CCW VRDC system emails alerts to you and your DUA project team at 75%, 90%, and 100% of the DUA allocations. To comply with the space usage limits, users within the DUA must take action by: 1) deleting any files no longer needed and/or 2) contacting the Research Data Assistance Center (ResDAC) to purchase additional space and/or 3) contacting the CCW Help Desk to delete or move data files associated with “Disabled” or “Disassociated” users.

Q: What happens when I reach my maximum space usage threshold and what should I do? (FAQ061)

A: When a DUA reaches 100% of the allocated space, all users within this DUA will no longer be able to perform tasks that write files to the space associated with that specific DUA. To comply with the space usage limits, users within the DUA must take action by: 1) deleting any files no longer needed and/or 2) contacting ResDAC to purchase additional space and/or 3) contacting the CCW Help Desk to delete or move data files associated with “Disabled” or “Disassociated” users.

Q: If we reach our SAS space threshold for a DUA but then delete an adequate number of files, how long will it take us to be able to run SAS programs again after the deletions? (FAQ062)

A: Assuming your SAS space usage remains below the threshold, you should have access to run SAS programs again within one hour.

Q: Does my SAS user home folder count towards my DUA space usage? (FAQ063)

A: CMS does not include the SAS user home folder space in the total DUA allocated space.

Q: Is there a limit on how much additional space users can purchase for a DUA? (FAQ064)

A: There is currently no limit on how much additional space users can purchase; however, requests of 50 TB or greater will require additional review. The intent of the CCW VRDC is for researchers to use CMS data to prepare summary data files for output. Keep in mind that the total size of all the files for output cannot exceed 1 GB.

Output Reviews

Q: Are there changes to my output reviews? (FAQ070)

A: Requests for output review using the File Transfer Request System (FTRS), which the CCW VRDC system currently assigns by individual user, will now assign at the DUA level. Researchers will get three output reviews per DUA per week, and innovators will get six output reviews per DUA per week, shared by all users on the DUA.

Q: Does the gigabyte (GB) limit per output review request still apply at the user level, or is this now at the DUA level? (FAQ071)

A: The GB limit is now at the DUA level. The FTRS system allows research DUAs up to 1 GB of output review, per week, shared by all users on that DUA. FTRS allows innovator DUAs up to 2 GB of output review, per week, shared by all users on that DUA. However, there is still a 1 GB limit per output review request.

Q: Why were the output review requests moved to the DUA level? (FAQ072)

A: CMS moved the output review requests to the DUA level because project data exported from the CCW VRDC should be summary-level, analytic results. Output files should be project-based summaries. Project teams should coordinate their final results within the CCW VRDC and determine as a team what requires output.

Q: Is there a purchase limit on how many output review requests per DUA users can request? (FAQ073)

A: The CCW VRDC support team will review each request to purchase additional output reviews to ensure resources are available.


Q: How do I log into the CCW environments?

A: Review the document CCW Okta Factor Enrollment and Management Guide for information on registering/managing multi-factor authentication and logging into all CCW environments.

Q: How do I change my CCW password?

A: After logging into the CCW secure website, click the link at the top of the page for ‘Change Password’. Select the blue information icon to review the password policy. Enter your old password followed by your new password twice then select ‘Submit’. If you’re having trouble logging in or changing your password, contact the CCW Help Desk.

Q: How do I recover or reset my CCW password?

A: If you have forgotten your password or have difficulty logging in, please contact the CCW Help Desk at or 1-866-766-1915.

Q: Is the CCW login ID case sensitive?  (FAQ014)

A: Yes. Enter your login ID in lowercase as some of the CCW systems are case sensitive and do not accept an uppercase login ID.

Q: I was previously logged into VMware Horizon Client and now am unable to login in again, what might be the cause for this?  (FAQ015)

A: When you are finished with your VMware Horizon Client session, the best practice to avoid issues logging in again is: if a program is currently running (i.e., SAS Enterprise Guide [SAS EG]) in the virtual desktop, disconnect from the session by "X"ing out of the window; if a program is not currently running, end the session by going to Start, then click the Log Off button.

Q: I changed my CCW password and now am not able to login. What should I do?  (FAQ016)

A: After you have changed your password, additional steps may be needed to complete the password change process. If you have any active VMware Horizon Client sessions running (showing option to Reconnect to desktop), logout of the session to clear the cached credentials. In addition, if you have a password embedded in a file, you must also change this password at this time.

Pricing Application

Q: What browsers can I use for the Pricing application?  (FAQ017)

A: The Pricing application works using Google Chrome, Mozilla Firefox and Microsoft Edge (Internet Explorer is not supported).

Q: How do I select multiple values -- for example SSA State Code -- when creating a study size estimate?  (FAQ018)

A: Use IN to select multiple values. Comma-separate the values. Or, if the value has a drop down, use the Ctrl button and select all values that apply.

Q: When creating a study size estimate, if I select multiple chronic conditions is this using the AND operator or the OR operator?  (FAQ019)

A: Researchers have the option to use the AND or OR operator when selecting multiple chronic conditions.

Q: Can I select multiple diagnosis codes in the same field? What about wild card or a range of values?  (FAQ020)

A: Ranges of HCPCS or procedure codes can be entered per field. You can add as many fields as needed for your estimate. The LIKE operator has been added for wild card use. When using the LIKE operator, you must enter the first three positions of the code, do not enter %.

Q: When creating a study size estimate, if I select multiple diagnosis, HCPCS, or procedure code is this using the AND operator or the OR operator?  (FAQ021)

A: Selecting multiple diagnosis, HCPCS, or procedure code uses the OR operator. Giving researchers the option of AND or OR is documented on our list of enhancements.

Q: Can I estimate a study size using NDC codes?  (FAQ022)

A: This application allows searches for ICD-10 diagnosis and procedure, CPT, and HCPCS codes. Searches for NDC codes are not available.

Q: Can I estimate a study size using Medicaid criteria?  (FAQ023)

A: The cohort estimator portion of this application, available on the Estimate Study Size - Medicaid page, now support Medicaid data. Medicaid Enrollee Counts are also available as a PDF document on the Data Pricing page of this application. Both Medicaid and Medicare/Medicaid Dual Eligible counts are provided. These counts may be manually entered in the "Population Size" field on the Data Pricing page.

Q: I am looking for a 20% sample of Medicare beneficiaries. Can I get a pricing estimate for this sample size?  (FAQ024)

A: A 20% sample for one year of Medicare beneficiaries is approximately 10.8 million beneficiaries. On the Data Pricing page of the application, select Population Size and enter 10,800,000. Select the files that you need for your study and submit the request to get pricing for a 20% sample.

Q: I want to study Medicaid only enrollees in New Jersey but the Data Pricing page of the application does not allow me to select a state.  (FAQ025)

A: CMS revised its data pricing, effective June 1, 2014. Medicaid files are no longer priced by state but rather by beneficiary count. To get the count of Medicaid enrollees in New Jersey, go to the Medicaid Enrollee Counts (PDF) document, which is also available on the Data Pricing page.

Q: I would like to get files for certain years which aren't listed on the Data Pricing page.  (FAQ026)

A: Each data file's corresponding years listed in the drop down menus are the current years available for that particular file. The application will be updated as new years become available for certain data files.

Q: When creating a Medicaid study-size estimate, what does "Total Months Enrolled" include? (FAQ027)

A: Medicaid "Total Months Enrolled" identifies the number of months an individual is enrolled in Medicaid in a given year regardless of the Medicaid program in which the individual is enrolled (Medicaid, Children's Health Insurance Program, or Medicaid Expansion).

Q: If I select a claim type code and a diagnosis code for a Medicaid estimate, and the diagnosis code is not found on the claim type selected, will the application include the beneficiary in the estimated results? (FAQ028)

A: The selection criteria is all joined with AND. Therefore, if the claim type code and diagnosis code parameters are selected, the diagnosis code must be found on the claim with the claim type code in order for the beneficiary to be counted in the final estimate.