Internal Revenue Manual
IRM 4.47.1 — Computer Audit Specialist Program (CAS)
Part 4. Examining Process
Chapter 47. Computer Audit SpecialistSection 1. Computer Audit Specialist Program (CAS) 4.47.1 Computer Audit Specialist Program (CAS) Manual Transmittal May 04, 2026 Purpose (1) This transmits revised IRM 4.47.1, Computer Audit Specialist, Computer Audit Specialist Program (CAS). Material Changes (1) Changes to this IRM are summarized in the table below: IRM Citation Title Change IRM 4.47.1.1 through IRM 4.47.1.1.7 Program Scope and Objectives through Related Resources Reorganized and updated the internal control subsections in accordance with requirements in IRM 1.11.2 IRM 4.47.1.1 Program Scope and Objectives Added new paragraphs for Primary Stakeholders and Contact Information IRM 4.47.1.1.3 Roles and Responsibilities Added paragraph (1) for Director, WCPA. Moved former IRM 4.47.2.2.1, Responsibilities of the Security Officer, to paragraph (6) of IRM 4.47.1.1.3 Former IRM 4.47.1.1.4 Program Goals Moved paragraph (1) to IRM 4.47.1.1.4, Program Management and Review, paragraph (2) Former IRM 4.47.1.1.4 Program Goals Moved paragraph (2) to IRM 4.47.1.1.3, Roles and Responsibilities, paragraph (2) IRM 4.47.1.1.4.1 Sources of Information Content moved from former IRM 4.47.2.6.1 IRM 4.47.1.1.4.2 Monitoring Activities Content moved from former IRM 4.47.1.3.2. Added d) IDR enforcement process and (e) Proper application of P-4-5 to paragraph (1) Former IRM 4.47.1.1.5 Training Moved to IRM 4.47.1.2. Paragraph (2) was merged to paragraph (1) IRM 4.47.1.1.5 Program Controls Added paragraphs on CAS system security and use of SRS for CAS service requests IRM 4.47.1.1.6 Acronyms Added acronyms for CPE, ROTER and SRS IRM 4.47.1.1.7 Related Resources Updated Virtual Library reference Former IRM 4.47.1.2 Record Evaluation and Feedback Moved to IRM 4.47.2.2, paragraphs (1) and (2) Former IRM 4.47.1.2.1 Issue Related Applications Moved to IRM 4.47.1.5.1 Former IRM 4.47.1.2.2 Case Related Applications Moved to IRM 4.47.1.5.2 Former IRM 4.47.1.2.3 Non-Case Related Applications Moved to IRM 4.47.1.5.3 Former IRM 4.47.1.2.4 Applications with Potential for Nationwide Use Moved to IRM 4.47.1.5.4 Former 4.47.1.3 Monitoring the CAS Program Moved to IRM 4.47.1.1.4, first sentence of paragraph (1) IRM 4.47.1.3 Referrals - Requests for CAS Services Moved from former IRM 4.47.2.3 Former IRM 4.47.1.3.1 Sources of Information Moved to IRM 4.47.1.1.4.1, paragraph (1) Former IRM 4.47.1.3.2 Monitoring Activities Moved to IRM 4.47.1.1.4.2 Former IRM 4.47.1.4 Data Files and Programs Moved to IRM 4.47.1.6 IRM 4.47.1.4 CAS Systems Security Moved from former IRM 4.47.2.2 and 4.47.2.2.2 Former IRM 4.47.1.4.1 Use of Non-IRS Facilities Moved to IRM 4.47.1.7, Procuring Data Processing Resources, Paragraphs (2) and (3) IRM 4.47.1.4.1 Physical Security of Hardware Moved from former IRM 4.47.2.2.2.1 IRM 4.47.1.4.2 Software and Taxpayer Data Moved from former IRM 4.47.2.2.2.2 IRM 4.47.1.4.3 Backup Files Moved from former IRM 4.47.2.2.2.3 IRM 4.47.1.4.4 Other Requirements Moved from former IRM 4.47.2.2.2.4 IRM 4.47.1.5 Application and Other Assignment Documentation Moved from former IRM 4.47.2.5 IRM 4.47.1.5.1 Issue-Related Applications Moved from former IRM 4.47.1.2.1 IRM 4.47.1.5.2 Case-Related Applications Moved from former IRM 4.47.1.2.2 IRM 4.47.1.5.3 Non-Case Related Applications Moved from former 4.47.1.2.3 IRM 4.47.1.5.4 Applications with Potential for Nationwide Use Moved from former IRM 4.47.1.2.4 IRM 4.47.1.6 Data Files and Programs Moved from former IRM 4.47.1.4 IRM 4.47.1.7 Procuring Data Processing Resources Moved from former IRM 4.47.2.9 to Paragraph (1). Moved from former IRM 4.47.1.4.1, Use of Non-IRS Facilities, to paragraphs (2) and (3) IRM 4.47.1.7.1 Taxpayer Facilities Moved from former IRM 4.47.2.9.1 IRM 4.47.1.7.2 Other Government Equipment Moved from former IRM 4.47.2.9.2 IRM 4.47.1.7.3 Local Service Bureaus and Time-Sharing Services Moved from former IRM 4.47.2.9.3 (2) Editorial changes were made throughout this IRM for plain language, spelling, grammar, punctuation, links, formatting, titles, and citations. Effect on Other DocumentsIRM 4.47.1 dated February 23, 2021 is superseded. AudienceAll IRS employees who request CAS services. Effective Date(05-04-2026)Ronald H. Hodge IIAssistant Deputy Commissioner Compliance IntegrationLarge Business and International Division
Program Scope and Objectives
4.47.1.1 (05-04-2026) Program Scope and Objectives Purpose: This section provides guidance to CAS with respect to their responsibilities in both examination cases and assignments from non-examination sources and information concerning the Computer Audit Specialist Program including: Authority Roles and responsibilities Program goals Scope of activity Monitoring Data files and programs Organization Training Audience: All IRS employees who request CAS services in support of field examination, non-examination assignments, and projects. Policy Owner: LB&I Policy under the Strategy, Policy and Governance office in the Assistant Deputy Commissioner Compliance Integration (ADCCI) organization and Director, Western Compliance Practice Area (WCPA). Program Owner: Director of Field Operations South Central (DFO-SC), WCPA. Primary Stakeholders: LB&I and all IRS enforcement divisions are the primary stakeholders for this IRM section. Contact Information: To recommend changes or to make any other suggestions to this IRM section, contact the IRM author or see SPDER's IMD Contacts list by referencing guidelines provided in IRM 1.11.6.5, Providing Feedback About an IRM Section - Outside of Clearance. A request or inquiry can also be made at the LB&I Policy Gateway.
Background
4.47.1.1.1 (05-04-2026) Background The CAS Program is a Large Business and International (LB&I) organization managed by the DFO-SC within the WCPA. The CAS Program's primary responsibility is to support field examinations involving the use of large electronic data files received from taxpayers and support tax issue development where complex data analysis using advanced programming skills is required. Field employees in the CAS Program consist of CASs and statistical sampling coordinators. A CAS is a trained revenue agent who has completed an intensive computer-training program concentrating on large computer systems that process voluminous amounts of data. While their primary activity is to support large and medium sized corporate and pass-through examinations focusing on various tax issues, CAS will also work on assigned projects requiring complex data analysis or application development. A statistical sampling coordinator (SSC) is a CAS with advanced training in statistical analysis and methodology. SSCs review taxpayer statistical samples used to generate amounts on a tax return or apply statistical sampling methodology to support tax issues raised during LB&I field examinations. Please refer to IRM 4.47.3 for guidelines and procedures a CAS or SSC should follow when considering the use of statistical sampling.
Authority
4.47.1.1.2 (02-23-2021) Authority By law, the IRS has the authority to conduct examinations under Title 26, Internal Revenue Code, Subtitle F – Procedure and Administration, Chapter 78, Discovery of Liability and Enforcement of Title, Subchapter A, Examination and Inspection, which includes, but is not limited to, the following IRC sections: IRC 7602, Examination of books and witnesses IRC 7605, Time and place of examination For additional information see IRM 4.10, Examination of Returns, and IRM 4.46, LB&I Examination Process.
Roles and Responsibilities
4.47.1.1.3 (05-04-2026) Roles and Responsibilities The Director, WCPA, is responsible for the policies and procedures in this IRM section. The DFO-SC has responsibility for the CAS program and the contents of this IRM. All inquiries, correspondence, reports, etc., pertaining to the CAS Program and any materials in this IRM should be directed to the DFO-SC. The DFO-SC will: Monitor the overall effectiveness of the program. Research technical and innovative aspects of Automatic Data Processing (ADP) examinations. Establish a national inventory of computer assisted audit techniques and issue guidelines for their use. Coordinate the securing of professional ADP technical assistance and advice to field offices. Plan and coordinate the development of computer programs for nationwide use as prototype programs and special purpose programs. Review, recommend, and assist in the development of proposed legislation, regulations, rulings, and procedures to resolve ADP auditing problems. Analyze, evaluate, and make recommendations on both technical and ADP training needs for examiners. Promote overall awareness of appropriate security procedures. Encourage the effective development and use of computer assisted audit techniques in carrying out the IRS's objectives. To support CAS Program goals, the DFO-SC will: Explore and identify areas where CAS support may be used to improve the quality and effectiveness of examinations, campaigns, and compliance projects. Work with the CAS territory managers to identify, evaluate, and procure the tools necessary for CASs to effectively and efficiently perform their assigned duties. Work with the CAS territory managers to provide training recommendations and assist in the development of training for CASs. Coordinate and monitor the completion of the annual Federal Information Security Management Act (FISMA) training that is required for each CAS and CAS manager. CAS territory manager - The CAS territory manager's role is to: Monitor, coordinate, and report on the overall effectiveness of the CAS Program within the territory. Provide inter- and intra-territory coordination for (1) assignments of CASs outside of their team areas; (2) requests between territories for services of examination personnel who have specialized talents needed; and (3) requests between territories for services regarding record retention evaluations for LB&I cases. Consult with and assist personnel in the resolution of ADP auditing problems. Monitor the territory's use of generalized, prototype, and special purpose computer programs in order to eliminate any duplication of effort. Accumulate, analyze, and disseminate information and experiences gained from review and monitoring of groups' activities. Provide coordination within IRS to plan and evaluate computer assisted techniques used in case examinations, and to ensure participation of CASs in the initial planning of each case and the use of CASs as information specialists. Assist in identifying ADP training needs and make recommendations regarding methods and content to the DFO-SC. Monitor, promote, and evaluate appropriate established security procedures. This includes assisting in the identification of security problems and following up to ensure that corrective actions identified during reviews by security functions have been implemented. Ensure that articles are submitted for sharing of programs to the DFO-SC. Identify computer applications and auditing techniques that may be useful on a nationwide basis and submit them to the DFO-SC. Review, discuss, and comment on the effective development and use of computer assisted audit techniques with territory personnel. Ensure that all territories utilize examination time from CASs in planning, performing, and coordinating computer assisted audits to the maximum extent possible. Hold conferences with professional accounting, legal, and tax societies and other interested groups to promote and gain favorable reception for computer assisted audits. Monitor and review all non-case related applications. CAS team manager - The CAS team manager's role is to: Establish procedures to ensure the maximum availability of CASs to examine computerized books and records where feasible and to increase examination efficiency. Identify ADP training needs for examining agents for program consideration. Identify and advise the CAS territory manager of unusual ADP auditing problems encountered during examinations. Make requests to the CAS territory manager for ADP assistance and provide ADP assistance when resources are available. Provide security for taxpayers' ADP records removed from their premises as prescribed in IRM. Use outside professional courses, trade magazines, etc., to provide opportunities for CASs to keep abreast of current ADP developments which affect accounting records processing. Hold conferences with professional accounting, legal and tax societies and other interested groups to promote and gain favorable reception for computer assisted audits. Develop procedures that cover basic security responsibilities within the CAS work areas. Promote the use of computer assisted auditing and statistical sampling techniques in all program areas. Participate in the initial planning of each examination. Ensure the CAS does not use any taxpayer machine-sensible records pertaining to a particular tax return until after the person responsible for examining the return has initiated the examination. Ensure the CAS is involved in the initial phases of the examination for the purpose of performing a systems analysis, identification of the audit trail or other application, including the use of statistical sampling techniques as deemed appropriate. Ensure that the CAS is involved throughout the examination for advice and application of innovative computer programs. At or near the conclusion of the examination, the CAS must be available to discuss prior applications, suggest changes or improvements and consider updating any record retention limitation agreement(s). Share with the case manager the activities of the CAS assigned to the examination. Consult with managers to ensure their record retention needs are being met. Participate in post examination critiques when deemed appropriate. Maintain an inventory of generalized, prototype, and special purpose computer applications used or developed in the group. These will be housed on the computer applications section of the CAS SharePoint site. Ensure the AIMS data base properly identifies entities having a record retention limitation agreement. Utilize direct examination time of CASs in planning, performing, and coordinating computer assisted audits to the maximum extent possible. Ensure that each use of a CAS represents the most efficient and effective possible employment of examination resources. Ensure that the most cost-effective equipment is used by CASs. Establish, maintain and monitor security procedures as may be required. Establish guidelines for the proper documentation of applications performed on each case. The Security Officer for all CAS Program equipment will be the CAS team manager. This person will: Ensure user accounts are assigned only to authorized users. Ensure individuals no longer requiring access to the system are removed from the list of authorized users. Ensure physical security of hardware and data is maintained and access to the computer room or area is controlled. Conduct functional security reviews of each site at least annually. Prepare an annual functional security review report. Ensure that new personnel are made aware of security requirements. Ensure that digital storage devices or printed output, containing taxpayer data or other sensitive information are properly secured, labeled, stored, and/or discarded. Ensure that backups are made and stored properly. Computer Audit Specialist (CAS) - The role of the CAS is the LB&I information specialist with regard to large complex computerized accounting systems. The CAS is also a recognized expert in the application of statistical sampling techniques. To fulfill this role, the CAS is involved in: Providing analyses of complex computerized accounting systems; Determining/recommending the most effective method to provide audit data required by examiners; Validating taxpayer created statistical samples; Providing examiners with technical guidance during IRS statistical sample development; Providing computer analyses of large volumes of data; Assisting examiners with the reconciliation of data to book trial balance and tax return line amounts; Designing applications using both standard and custom computer programs, and Searching continually for creative and innovative ways to use computer assisted auditing techniques.
Program Management and Review
4.47.1.1.4 (05-04-2026) Program Management and Review The effectiveness and efficiency of the CAS Program is monitored by management using automated systems, periodic time reports and other sources of information. The information gathered is to be used to evaluate the effectiveness of the CAS Program. It is not to be used to evaluate individual CAS. All levels of management must ensure adherence to current IRS policy and guidance, such as IRM 1.5.2.11.2, which prohibits the use of Records of Tax Enforcement Results (ROTERS) in evaluating employee performance. This information is used to evaluate and monitor the CAS Program objectives. Program Goal: The organizational goal of the CAS Program is to provide efficient access to and analyses of electronic records to support the activities of the LB&I business unit. To accomplish this goal, the CAS Program will: Improve the efficiency and effectiveness of LB&I field examinations by supporting tax issues identified by audit teams. Improve tax compliance by using advanced application and programming skills to identify and develop tax issues during LB&I field examinations. Support LB&I projects by using advanced software application and programming skills to analyze and prepare large and/or complex electronic data files. Support IRS business units by developing custom software applications that can be used by IRS employees to enhance the performance of their jobs. Improve the efficiency and effectiveness of LB&I tax examinations, studies, and projects by optimizing the use of statistical sampling methods when appropriate.
Sources of Information
4.47.1.1.4.1 (05-04-2026) Sources of Information The Issue Based Management Information System (IBMIS) is used to monitor the activities of the CAS. This automated system provides activity on a case by case basis. It provides information as to the time planned and expended by all members of the examination team, including CASs. It also provides information on the different aspects of CAS involvement in significant issues and in the application of statistical sampling auditing techniques. CAS management periodically reviews IBMIS reports for managing case information for tracking, planning, and reporting. Examples of IBMIS reports used by CAS management include: Specialists Open Case Inventory SRS Referral Reports Specialists Workload Review IDR Enforcement Report (at group level) LB&I P-4-5 Examiner Report Specialists DET NonDET Report (at team level) CAS Stat Sampling Open Cases Report
Monitoring Activities
4.47.1.1.4.2 (05-04-2026) Monitoring Activities Using IBMIS allows for monitoring: Level of computer audit support being provided by CASs on significant issues within LB&I. Use of statistical sampling auditing techniques in LB&I. Amount of CAS designated staff days expended, by activity code. Compliance with the IDR enforcement process. Proper application of Policy Statement 4-5 (P-4-5) to ensure consistent and appropriate CAS support in examination activities. IBMIS will be reviewed to determine if CAS participation is appropriate for their approved scope of the examination. Territory and team managers responsible for SRS Referral input should have ongoing discussions to determine if all reasonable requests for CAS assistance are being filled to the satisfaction of the requesting party, and to explore areas where assistance should, or could have been provided or improved. Record retention activity will be reviewed to ensure that all appropriate cases received adequate record retention agreement consideration. Record retention limitation agreements will be reviewed to determine if they meet examination needs, including those of any examination specialty. Outdated agreements must be reviewed to determine if suitable action has been initiated on cases where there is a reasonable potential for the use of computer assisted audit techniques in future examinations.
Program Controls
4.47.1.1.5 (05-04-2026) Program Controls Program controls for the CAS Program include CAS system security, which is described in IRM 4.47.1.4 , CAS System Security. The CAS Program uses the Specialist Referral System to manage CAS service requests. See IRM 4.47.1.3 , Referrals - Requests for CAS Services, for details.
Acronyms
4.47.1.1.6 (05-04-2026) Acronyms The table below contains commonly used acronyms: Acronym Term ADP Automatic Data Processing AIMS Audit Information Management System CAS Computer Audit Specialist CI Criminal Investigation CPE Continuing Professional Education DFO-SC Director of Field Operations South Central ERCS Examination Returns Control System FISMA Federal Information Security Management Act IBMIS Issue Based Management Information System IMS Issue Management System LB&I Large Business & International ROTER Records of Tax Enforcement Results SB/SE Small Business/Self-Employed SQL Structured Query Language SRS Specialist Referral System SSC Statistical Sampling Coordinator TE/GE Tax Exempt & Government Entities UIL Uniform Issue Listing WCPA Western Compliance Practice Area
Related Resources
4.47.1.1.7 (05-04-2026) Related Resources Technical and procedural information used by CAS to accomplish program goals are described in IRM 4.47.2, CAS Technical and Procedural Information. Technical and procedural information used by SSC to accomplish program goals are described in IRM 4.47.3, Statistical Sampling Auditing Techniques. More information about the CAS Program may be found in the Virtual Library: Computer Audit Specialist Knowledge Base.
Training
4.47.1.2 (05-04-2026) Training It is important that CASs have the highest level of expertise to fully support LB&I activities. In addition to the core training, CASs will receive continuing professional education and advanced training in other computer assisted audit techniques as they become relevant or pertinent. CASs and CAS team managers will complete 8 hours of FISMA security related information technology training annually. CAS territory managers will complete 4 hours of FISMA related training annually.
Referrals – Requests for CAS Services
4.47.1.3 (05-04-2026) Referrals – Requests for CAS Services The CAS Program encourages referrals on all cases, and from all business units, where the assigned agent believes the examination process would benefit from CAS engagement. With a primary focus on LB&I examinations, referrals to CAS are mandatory for tax returns with an activity code of 221 and above. Requests for CAS services are made by the assigned agent using the Specialist Referral System (SRS). Submission of a Referral should be completed early in the examination, upon case assignment to the assigned agent, to ensure proper CAS engagement. A limited review and assessment by a CAS is available to determine if a referral is warranted. This request can be made within the SRS system using the Consultation process. Separate SRS referrals for related entities should be submitted as soon as it is determined that the returns will be examined. The SRS referral for a CAS should include a LIN link for the latest return of the exam cycle. Once a referral has been made, the CAS team manager will generally assign, transfer or reject the referral within 5 business days. Once the referral has been assigned by the CAS team manager, the assigned CAS will generally contact the referring revenue agent within 5 business days or less. If the referral is rejected, the requester should contact the CAS manager with any questions or concerns.
CAS System Security
4.47.1.4 (05-04-2026) CAS System Security This section presents the procedures to be followed by security personnel in maintaining systems security for the CASs. Commercially developed system software is utilized, and application software is developed, maintained, and modified by the CASs as required to meet the unique needs of each examination. The most significant ongoing items in these security procedures are the security breach detection procedures and password integrity. Particular attention should be given to these areas. Established procedures and requirements described below are followed to ensure the security of the CAS equipment and data.
Physical Security of Hardware
4.47.1.4.1 (05-04-2026) Physical Security of Hardware All systems and peripheral equipment shall be kept in a controlled area when possible, which can be monitored by authorized users during working hours and locked after hours. Whenever a non-IRS person, such as a maintenance service employee, enters the controlled area, at least one IRS employee knowledgeable of the system will accompany the person and monitor his or her activity. When transferring taxpayer data from digital storage devices that will be running after hours and not in a controlled area, the digital storage device must be properly secured to prevent loss.
Software and Taxpayer Data
4.47.1.4.2 (05-04-2026) Software and Taxpayer Data All users must be cleared to handle taxpayer data, but access to files will be limited, to those with a need to know. Taxpayer data which is on magnetic media will be afforded appropriate security and maintained or destroyed in accordance with established record retention policy. Printed data will be kept secured until distributed or destroyed. Hard copy to be destroyed should be shredded, placed in a shred bin maintained in office space, or otherwise rendered unreadable. Magnetic media containing taxpayer data which are to be discarded should be turned in to IT for proper disposal. Refer to IRM 10.5.1, Privacy Policy, and IRM 10.5.1.6.10, Disposition and Destruction, for additional guidance on proper disposal of hard copy paper and electronic media.
Backup Files
4.47.1.4.3 (05-04-2026) Backup Files Backups of application files will be taken as frequently as is prudent for a particular site. A systems file backup and an application files backup will be stored away from the computer room so as to preclude total loss of data from a localized fire or other disaster. Original backups may be used for this purpose; duplicate backups are not required. All backups will be kept in a secured location.
Other Requirements
4.47.1.4.4 (05-04-2026) Other Requirements Sensitive data will be cleared from the screen upon "logoff" or leaving a terminal. Computer room(s) will be cleaned by janitorial service personnel only during working hours.
Application and Other Assignment Documentation
4.47.1.5 (05-04-2026) Application and Other Assignment Documentation Complete and proper documentation of computer applications developed and/or used by the CAS in case work is very important. At a minimum, this documentation should be in a format to allow others needing to determine work performed on a case assignment to be able to review the trail of work performed. Complete and proper documentation of technical issue development including involvement in statistical sampling by the CAS in case work is very important. At a minimum, this documentation should be in a format to allow others needing to determine work performed on a case assignment to be able to review the trail of work performed. Upon completion of the work assignment, the CAS should complete the form titled "Computer Assisted Audit Program Closed Case Documentation" available from the team manager. The CAS should provide this document to the CAS manager along with a copy of the audit plan, CAS activity record, and any record evaluation feedback provided to the taxpayer. These documents comprise the CAS case closing package. The case manager should sign the closed case document and provide a copy to the case manager. The CAS case closing package should be retained for historical purposes. The CAS manager is responsible for ensuring the case closing package is loaded into the Issue Management System (IMS). The DFO-SC has the responsibility for coordinating the development of programs for nationwide application, testing them for operational readiness, and for preparing full documentation. Originators of proposed applications may, however, be called upon to assist in this task.
Issue Related Applications
4.47.1.5.1 (05-04-2026) Issue Related Applications In order to monitor issue related applications, the CAS and CAS manager should ensure that the appropriate Uniform Issue Listing (UIL) codes are used when preparing audit plans and as time is charged to each case. The UIL codes used by other audit team members should be used by the CAS when providing support and assistance directly to the development of the issue. Time spent developing applications, gathering or analyzing data or interpreting results in the development of an issue should be charged to the same UIL codes as the other members of that issue team. UIL 7602.00 – This UIL code should be used for book to tax reconciliations (i.e. high-level reconciliation). This includes reconciliations using tax preparation software data, reconciliations involving schedule M items, or account number to tax return line number mapping. UIL 7453.31 – This UIL code should be used for general CAS related activity performed prior to issue identification stage of the examination (not specific to a single issue). It may also be used for reconciliations and processing of data below the book to tax reconciliation level when no issues are involved. For all other reconciliations and processing work performed as a result of audit issue development refer to guideline (1) above. UIL 6662.01 – This UIL code should be used when considering inadequate records or other potential record retention or internal control inadequacies (including the issuance of feedback letters to taxpayers).
Case Related Applications
4.47.1.5.2 (05-04-2026) Case Related Applications CASs are primarily intended to be used in the examination of LB&I tax returns by performing case related applications which are consistent with the role of the CAS as defined in the IRM. Case related is defined as all computer applications where time is properly chargeable to direct examination time on the ERCS Monthly Time Report. Case related applications also include TE/GE, SB/SE, CI, Appeals, Counsel, and Grand Jury activities even though time may properly be charged to non-direct examination time, and regardless of the case's status on AIMS. The application must involve analyzing data from the taxpayer's books and records and/or the analysis of other information to determine compliance with the Internal Revenue Code.
Non-Case Related Applications
4.47.1.5.3 (05-04-2026) Non-Case Related Applications Non-case related is defined as all management reports and applications which do not relate to the examination of the taxpayer's books and records or other relevant data. Non-CAS staff should be used to the maximum extent possible for these types of applications. Non-case related applications requiring more than 16 hours of CAS resources require CAS territory manager approval. Non-case related applications requiring 16 hours or less of CAS resources requires CAS team manager approval.
Applications with Potential for Nationwide Use
4.47.1.5.4 (05-04-2026) Applications with Potential for Nationwide Use CASs should identify and explore potential computer applications that may have broad nationwide use to expedite or reduce the cost of investigations, examinations, and special projects. These ideas may be developed during examination or special project work. These ideas should be submitted to the DFO-SC as early as possible in the development stage so they can be reviewed before extensive resources are expended and possible duplication of effort takes place.
Data Files and Programs
4.47.1.6 (05-04-2026) Data Files and Programs All taxpayer information and computer programs must be controlled and stored in accordance with IRM Part 10 (Security, Privacy, Assurance and Artificial Intelligence) and the currently applicable data security guidance. Appropriate security must be maintained for all non-taxpayer data files and programs. When original machine-sensible records are taken from a taxpayer's place of business, care must be taken to ensure that appropriate security measures are taken and that an appropriate receipt is issued pursuant to Policy Statement 4–8. All machine-sensible media shipped between IRS offices or non-IRS offices must be transmitted by a traceable and receipted method. Consideration should be given to using Form 3210, Document Transmittal.
Procuring Data Processing Resources
4.47.1.7 (05-04-2026) Procuring Data Processing Resources The CAS must have adequate equipment in order to complete any computer assisted audit application. Equipment resources to be used should include those provided by: Taxpayer facilities, CAS Program, IRS service centers, other government owned equipment, local service bureaus, commercial time-sharing services. In all instances CAS Program equipment should be used to the maximum extent possible to compile, test and debug programs prior to execution. If any CAS is offered free computer processing by another agency, IT Security and Disclosure functions must be notified to ensure that appropriate security is maintained. Contracts with commercial firms, inter-agency agreements and no-cost agreements may require prescribed safeguards, provisions, pre-contract award site reviews, and annual contractor safeguards review. All jobs must be processed in such a manner that the case or project will be identifiable in billing statements. Billings should be reviewed regularly by CAS group managers to ensure that only official and authorized work is performed, and that there have been no breaches of security. Copies of invoices should be obtained for this purpose from the IRS official that receives the vendor invoices and approves them for payment. The following are requirements for using commercial time-sharing systems. Sign-off procedures must be used when leaving the terminal. A unique password and user ID or other access identifier should be used to prevent unauthorized access. CASs must have an individual password and user ID assigned. The user ID must be disabled or deleted whenever a person leaves the CAS group. Proper security must be maintained on all passwords limiting knowledge of the password to the CAS and that person's team manager. All passwords must be changed per the security policy regarding use of the system or if a security breach is suspected.
Taxpayer Facilities
4.47.1.7.1 (05-04-2026) Taxpayer Facilities All CASs and their managers must solicit voluntary use of necessary computer facilities from taxpayers under examination where computer assisted audit techniques will be used. It is desirable to use the taxpayer's computer for computer assisted auditing techniques since the equipment is compatible with the records, and the taxpayer's ADP staff is familiar with the data. Taxpayer facilities shall not be used for other purposes or for longer than is necessary to complete the examination.
Other Government Equipment
4.47.1.7.2 (05-04-2026) Other Government Equipment On occasion, another government agency may permit CASs to use its computer facilities. When such facilities are used, even if provided without charge, Area and Territory Security and Disclosure functions must be notified to ensure that appropriate security is maintained.
Local Service Bureaus and Time-Sharing Services
4.47.1.7.3 (05-04-2026) Local Service Bureaus and Time-Sharing Services The CAS Program secures time-sharing systems and local off-site data processing facilities for use by CASs. These services should be used only when the use of taxpayer computer facilities, IRS facilities or other Commercial government owned equipment is not possible. The most cost-effective system should be selected for the intended application. Funds for securing ADP services are provided in accordance with regular fiscal procedures. The DFO-SC must approve all applications using local service bureaus or commercial time-sharing services that will exceed $10,000 in cost. The requirement to file GSA Form 2068-A, Quarterly Report of ADP Services, has been eliminated by GSA. Area and Territory Security and Disclosure functions should be contacted and all security requirements shall be adhered to.
Source: official text