LibGuides: GovSpeak: A Guide to U.S. Government Acronyms & Abbreviations: I

I2U2	India, Israel, United Arab Emirates, United States
i2X	Interconnection Innovation e-Xchange
i3	Investing In Innovation
I&A	Industry & Analysis \| Office of Intelligence and Analysis
I&M	Biological Inventory and Monitoring (changed to ECO) \| Inventory and Monitoring
I&O	Industry and Occupation
IA	International Affairs (changed to International Operations) \| Import Administration (changed to Enforcement and Compliance) \| Indian Affairs \| Office of International Affairs (unable to verify 1/25)
IAAF	Interagency Accessibility Forum
IAAO	International and Academic Affairs Office
IAB	InterAgency Board
IABC	International Analysis and Banking Condition Division (unable to verify 10/19)
IAC	Industrial Advisory Committee \| Industrial Assessment Center \| Interagency Check \| Inventors Assistance Center \| Investment Advisory Council \| White House Environmental Justice Interagency Council (unable to verify 2/25)
IACB	Indian Arts and Crafts Board
IACC	Interagency Autism Coordinating Committee
IACT	Institute for Atom-Efficient Chemical Transformations (unable to verify 6/19)
IACUC	Institutional Animal Care and Use Committee
IAD	Industry Analysis Division \| Information Access Division \| Information Assurance Directorate (changed to Cybersecurity) \| International Affairs Division, ATF \| International Affairs Division, TTB \| Investigative Analysis Division
IADRP	International Alzheimer's and Related Dementias Research Portfolio
IADRWG	Interagency Alternative Dispute Resolution Working Group

IAE	Integrated Award Environment
IAEGC	Inter-Agency Electronic Grants Committee (changed to grants.gov)
IAEM	Institute for Advanced Electron Microscopy
IAF	Inter-American Foundation
IAG	Indigenous Animals Harvesting and Meat Processing Grant Program \| Industries at a Glance
IAIP	Infrastructure Analysis and Infrastructure Protection Program (unable to verify 1/08)
IAIWG	International Activities Interagency Working Group
IAL	Innovative Approaches to Literacy
IALS	International Adult Literacy Survey
IAM	Indian Affairs Manual
IAO	Interagency Office (unable to verify 7/22)
IAP	International Activities Program \| International Agricultural Productivity \| Medicaid Innovation Accelerator Program \| Office of Impact Aid Programs
IAPD	Investment Adviser Public Disclosure
IAPE	Office of Intergovernmental Affairs and Public Engagement
IAQ	Indoor Air Quality
IARPA	Intelligence Advanced Research Projects Activity
IARPC	Interagency Arctic Research Policy Committee
IASA	International Aviation Safety Assessment
IASAP	Indian Alcohol and Substance Abuse Program (unable to verify 12/18)
IASOA	International Arctic Systems for Observing the Atmosphere (unable to verify 4/23)
IASP	Integrated Aviation Systems Program
IAT	Interagency Aviation Training
IATP	Intelligence Analyst Training Program (unable to verify 8/18)
IAWG	Interagency Working Group
IB	Intelligence Branch \| International Bureau (changed to OIA)
IBA	Industrial Base Assessments (changed to IPA)
IBAB	International Broadcasting Advisory Board
IBAS	Industrial Base Analysis and Sustainment (unable to verify 5/23)
IBAT	Interagency Bolt Action Team

IBB	International Broadcasting Bureau (changed to BBG)
IBC	Interior Business Center
IBCE	Institute of Bioenergy, Climate, and Environment
IBEX	Interstellar Boundary Explorer
IBFS	International Bureau Electronic Filing System
IBIA	Interior Board of Indian Appeals
IBIP	Indian Business Incubators Program
IBIS	International Biometric Information Sharing Program
IBL	Ion Beam Laboratory
IBLA	Interior Board of Land Appeals
IBMP	Interagency Bison Management Plan
IBN	Indicators of Broadband Need
IBP	Industrial Base Policy \| International Buyer Program (unable to verify 4/23)
IBR	Incorporation by Reference \| Industrial Base Resilience
IBRC	Innovative Bridge Research and Construction Program (unable to verify 1/15)
IBRD	Innovative Bridge Research and Deployment Program (unable to verify 1/15)
IBS	Integrated Biometric System (pdf) \| International Banking Supervision
IBTrACS	International Best Track Archive for Climate Stewardship
IBWC	International Boundary and Water Commission
IBx	Program Office for Innovation and Industrial Base Expansion

IC	Intelligence Community
IC ACC	Intelligence Community Advanced Campaign Cell (unable to verify 1/25)
IC3	Internet Crime Complaint Center
ICAC	Internet Crimes Against Children Task Force Program (unable to verify 10/19)
ICAD	Intelligent Computer Assisted Detection
ICAM	Identity, Credential, and Access Management \| Innovative Coordinated Access and Mobility Pilot Program
ICAMS	Interagency Council for Advancing Meteorological Services
I CARE	Integrity, Commitment, Advocacy, Respect, and Excellence
ICARS	Interagency Council on Agricultural and Rural Statistics
ICASS	International Cooperative Administrative Support Services
ICATT	Increasing Community Access to Testing for COVID-19
ICBEMP	Interior Columbia Basin Ecosystem Management Project (archived site)
ICBS-R	Interagency Cache Business System Re-engineering
ICC	Census Integrated Communications Campaign \| Office of Incident Command and Control
ICCA	International Conservation Chiefs Academy
ICCE	Office of International Climate and Clean Energy (discontinued)
ICCPUD	Interagency Coordinating Committee on the Prevention of Underage Drinking (alternate link archive)
ICCVAM	Interagency Coordinating Committee on the Validation of Alternative Methods
ICD	Intelligence Community Directive \| Interagency Contract Directory \| International Classification of Diseases
ICDBG	Indian Community Development Block Grant
ICDR	Interagency Committee on Disability Research
ICE	Immigration and Customs Enforcement \| Infrastructure Carbon Estimator \| Integrated Chemical Environment \| Interactive Catchment Explorer
ICEIWG	Indian Country Energy and Infrastructure Working Group
ICEPIC	Immigration and Customs Enforcement Pattern Analysis and Information Collection System
ICESat-2	Ice, Cloud, and Land Elevation Satellite-2
ICF	International Classification of Functioning, Disability and Health \| Office of Inertial Confinement Fusion (unable to verify 8/18)
ICFS	International Communications Filing Systems
ICH	Interagency Council on Homelessness
ICHNR	Interagency Committee on Human Nutrition Research
ICILS	International Computer and Information Literacy Study
ICIS-AIR	Integrated Compliance Information System-Air

ICIS-NPDES	Integrated Compliance Information System-National Pollutant Discharge Elimination System
ICITAP	International Criminal Investigative Training Assistance Program
ICLUS	Integrated Climate and Land-Use Scenarios
ICM	Integrated Corridor Management
ICMOB	Intramural Clinical Management and Operations Branch
ICOADS	International Comprehensive Ocean-Atmosphere Data Set
ICON	Ionospheric Connection Explorer
ICOR	Immigration Court Online Resource
I-Corps	Innovation Corps
iCOUP	Institute for the Cooperative Upcycling of Plastics
ICP	Indian Children's Program (unable to verify 2/25) \| Informed Compliance Publication \| International Information and Communications Policy
ICPD	Individual and Community Preparedness Division (unable to verify 2/25)
ICPG	Intelligence Community Policy Guidance
ICPM	Intelligence Community Policy Memorandum
ICPO	International Cooperative Programs Office
ICPPS	Interagency Council on Printing and Publications Services (replaced by FPC)
ICR	Information Collection Request \| Information Collection Review \| Information Collection Rule \| Information Coordination and Reporting Branch (unable to verify 11/24)
ICRCs	Injury Control Research Centers
ICRO	Information Collection Review Office
ICS	Incident Command System \| Industrial Control Systems \| Integrated Country Strategy (unable to verify 2/25) \| International Cyberspace Security \| Investment Climate Statements
ICS-CERT	Industrial Control Systems Cyber Emergency Response Team (retired 2/23; previously merged into NCCIC)
ICSD	Inorganic Crystal Structure Database (requires login)
ICSJWG	Industrial Control Systems Joint Working Group

ICSO	Interior Complex Security Operations
ICSP	Interagency Committee on Standards Policy \| Interagency Council on Statistical Policy
ICT	Indigenous Connectivity and Technology Division
ICTAP	Interoperable Communications Technical Assistance Program
ICTIME	Interagency Center for Trade Implementation, Monitoring, and Enforcement
ICTS	Information and Communication Technology Survey
ICU	Influenza Coordination Unit (unable to verify 2/16)
ID	Infectious Diseases \| Influenza Division \| Intelligence Division
IDA	Individual Development Accounts \| Interactive Data Analyzer
IDB	Integrated Database \| International Data Base \| Investigational Drug Branch
IDC	Imaging Data Commons
ID-CTP	Immune Deficiency Cellular Therapy Program
IDD	Infrastructure Protection and Disaster Management Division (unable to verify 5/14)
IDDA	Income Distributions and Dynamics in America
IDDB	Intellectual and Developmental Disabilities Branch
IDE	International Data Explorer
IDEA	Index of Economic Activity \| Individuals with Disabilities Education Act \| International Data & Economic Analysis
IDEAS	IARPA Distribution & Evaluation System \| Implementing Diagnostic Excellence Across Systems \| Interagency Disability Educational Awareness Showcase (unable to verify 8/13) \| Inter-Disciplinary Engagement in Animal Systems
IDENT	Automated Biometric Identification System
IDEP	Integrated Diabetes Education Program (defunct)
IdHSC	Identity History Summary Checks
IDI	Interagency Data Inventory
IDIS	Integrated Disbursement and Information System
IDLH	Immediately Dangerous To Life or Health
IDMS	Investigations Data Management System
IDN	International Directory Network
IDP	Industrial Demonstrations Program
IDPB	Infectious Diseases Pathology Branch
IDR	Income-Driven Repayment \| Integrated Data Repository
IDRS	Integrated Data Retrieval System (pdf)
IDS	Incident Data System \| Investigations Database System
IDSR	Integrated Disease Surveillance and Response (merged into DGHP)
i-DST	Integrated Decision Support Tool
IDSWD	Informatics and Data Science Workforce Development

IEA	Integrated Ecosystem Assessments \| Office of Independent Enterprise Assessments (changed to EA) \| Office of Intergovernmental and External Affairs
IEC	International Energy Commitments
IECMH	Infant Early Childhood Mental Health
IECMHC	Center of Excellence for Infant and Early Childhood Mental Health Consultation
IED	Office of Indian Economic Development
iEdison	Interagency Edison
IEDO	Industrial Efficiency and Decarbonization Office
IEED	Office of Indian Energy and Economic Development (changed to IED)
IEG	Institute for Ethics in Government \| Instrument Enhanced Grading program
IEID	Influenza and Emerging Infectious Diseases Division
IEIP	International Emerging Infections Program (unable to verify 9/23)
IELP	Innovation and Early Learning Programs
IELS	International Early Learning Study
IENC	Inland Electronic Navigational Charts
IEO	International Energy Outlook
IER	Immigrant and Employee Rights Section
IERH	International Emergency and Refugee Health (changed to ERRB)
IES	Institute of Education Sciences \| International Energy Statistics \| Investigative and Enforcement Services
IESC	Indian Energy Service Center
IEUBK	Integrated Exposure Uptake Biokinetic
IE&VT	Industries, Education, and Vocational Training Division (unable to verify 8/17)
IFAC	In-Field Address Canvassing
IFAP	Information for Financial Aid Professionals (changed to Knowledge Center then FSA Partner Connect)
I-FAST	Innovations in Food and Agricultural Science and Technology Prize Competition (unable to verify 3/21)
IFD	Division for International Finance and Development
IFDP	International Finance Discussion Papers
iFECS	integrated Federal Employees' Compensation System
IFFC	Illicit Finance Fusion Cell
IFLE	International and Foreign Language Education
IFMAT	Indian Forest Management Assessment Team
IFO	International Field Offices
IFPM	Interagency Fire Program Management Standard
IFPS	Institute of Food Production and Sustainability
IFS	Center for Innovative Finance Support
IFSAC	Interagency Food Safety Analytics Collaboration
IFSM	Integrated Farm System Model

IFSN	Institute of Food Safety and Nutrition
IFSS	Integrated Food Safety System
IFTDSS	Interagency Fuel Treatment Decision Support System
IFU	International Field Units (unable to verify 4/15)
IGA	Office of Intergovernmental Affairs
IGBST	Interagency Grizzly Bear Study Team
IGCE	Independent Government Cost Estimate (merged into buy.gsa.gov; requires login)
IGEMS	Interior Geospatial Emergency Management System (unable to verify 2/18)
IGIA	Interagency Group on Insular Areas
IGIM	Interagency Group on Integrative Modeling
IGMS	Integrated Grants Management System (changed to NGGS)
IGNITE	Implementing Genomics in Practice \| Inspector General Network for Information and Telecommunications Exchange
IGP	Office of Information Governance and Privacy (changed to OIGP)
IGRA	Integrated Global Radiosonde Archive
IGSB	Institute for Genomics & Systems Biology (unable to verify 4/19)
IHA	Indian Housing Authority (changed to PIH)
IHB	Office of International Health and Biodefense (unable to verify 9/23)
IHBG	Indian Housing Block Grant
IHCIF	Indian Health Care Improvement Fund
IHEC	Interdepartmental Health Equity Collaborative (unable to verify 2/25)
IHM	Images from the History of Medicine \| Indian Health Manual
IHP	Individuals and Households Program
IHPES	Indian Health Performance Evaluation System
IHR	International Health Regulations
IHRU	International Human Rights Unit
IHS	Indian Health Service
IHSC	Immigration and Customs Enforcement Health Service Corps
IHSDM	Interactive Highway Safety Design Model

IIA	Office of International and Integrative Activities (changed to OIA)
IIAD	International and Interagency Affairs Division
IIB	Infections and Immunoepidemiology Branch
IIC	Institute for Integrated Catalysis
IID	Inactive Ingredient Database
IIEAC	Invention, Innovation, and Entrepreneurship Advisory Committee
IIF	Injuries, Illnesses, and Fatalities
III	Interstate Identification Index
IIM	Individual Indian Money Accounts
IIMD	Identity and Information Management Division
IIOG	Interagency Interoperability Oversight Group (unable to verify)
IIP	Bureau of International Information Programs (unable to verify 6/19) \| Division of Industrial Innovation and Partnerships (replaced by TIP) \| Innovation and Intellectual Property
IIRD IWG	Information Integrity R&D Interagency Working Group (unable to verify 12/24)
IIS	Division of Information & Intelligent Systems \| Immunization Information Systems
IISAR	Immunization Information Systems Annual Report
IITF	International Institute of Tropical Forestry
IIWG	Interagency Investment Working Group

IJC	International Joint Commission
ILA	Independent Living Administration (unable to verify 4/20)
ILAB	Bureau of International Labor Affairs
ILC	International Labor Comparisons
ILCP	Indian Land Consolidation Program
ILD	Intelligence Law Division
ILER	Individual Longitudinal Exposure Record
ILGP	Indian Loan Guarantee and Insurance Program
ILINet	U.S. Outpatient Influenza-like Illness Surveillance Network
ILN	Intelligence Learning Network
IL-OIB	Independent Living Services for Older Individuals Who Are Blind
ILS	Independent Living Services
iLSA	Institute for Laser Science Applications (changed to CHEDS)
IM	Division of Investment Management
IMAAC	Interagency Modeling and Atmospheric Assessment Center
IMACS	International Myositis Assessment and Clinical Studies Group
IMAGE	ICE Mutual Agreement between Government and Employers
IMAP	Interstellar Mapping and Acceleration Probe
IMAT	Innovative Molecular Analysis Technologies
IMATS	Inventory Management and Tracking System (unable to verify 1/20)

IMC	Imaging Mass Cytometry Laboratory \| Interagency Management Council for Federal Telecommunications (unable to verify 12/12)
IMCL	Irradiated Materials Characterization Laboratory
IMCO	Interagency Meteorological Coordination Office
IMCP	Investing in Manufacturing Communities Partnership (unable to verify 4/20)
IMDCC	Interagency Marine Debris Coordinating Committee
IMDS	International Macroeconomic Data Set
IME	Institute of Molecular Engineering (unable to verify 9/17)
IMF	International Monetary Fund
IMG/M	Integrated Microbial Genomes & Microbiomes
IMG/VR	Integrated Microbial Genomes/Virus
IMIS	Integrated Management Information System
IML	Irradiated Materials Laboratory
IMLGS	Index to Marine and Lacustrine Geological Samples
IMLS	Institute of Museum and Library Services
IMM	Immigration Law Division
IMMDL	Insect Management and Molecular Diagnostics Laboratory
IMMPaCt	International Micronutrient Malnutrition Prevention and Control Program
ImmPort	Immunology Database and Analysis Portal
IMP	Inventory Management Plan
IMPACT	Interagency Implementation and Advanced Concepts Team
IMPACT-MH	Individually Measured Phenotypes to Advance Computational Translation in Mental Health
IMRL	Integrated Materials Research Laboratory
IMS	Interactive Multisensor Snow and Ice Mapping System
IMS/PIC	Inventory Management System/PIH Information Center
INA	Office of International Affairs
INADs	Investigational New Animal Drugs
INB	Integrative Neuroscience Branch
InCA	Interactive Cancer Atlas (unable to verify 8/18; likely changed to USCS Data Visualizations)
INCA	Interagency National Climate Assessment Working Group (unable to verify 2/18)
InciWeb	Incident Information System
INCLUDE	INvestigation of Co-occurring conditions across the Lifespan to Understand Down syndromE Project
INCSR	International Narcotics Control Strategy Report
INCUS	Investigation of Convective Updrafts

IND	Interplanetary Network Directorate \| Investigational New Drug
INDEX	ImagiNg Data EXchange
IndIWG	Indicators Interagency Working Group
INEAP	Interagency Network of Enterprise Assistance Providers (unable to verify 9/16)
INEPC	Office of International Nuclear Energy Policy and Cooperation
INF	Intermediate Range Nuclear Forces
IN FISH	Inclusive NOAA Fisheries Internship Program (unable to verify 2/25)
InfoLaw	Information Law Division
INFRA	Infrastructure for Rebuilding America
InFRM	Interagency Flood Risk Management
INL	Bureau for International Narcotics and Law Enforcement Affairs \| Idaho National Laboratory
INL/AME	Office of Africa and Middle East Programs (unable to verify 6/19)
InPort	NMFS Information Portal
INR	Bureau of Intelligence and Research
INRM	Integrated Natural Resource Management (unable to verify 1/25)
INRMPs	Integrated Natural Resources Management Plans
INS	Immigration and Naturalization Service (changed to USCIS)
INSD	FBI Inspection Division
INSITE	INtegrated Support for Impacted air-Traffic Environments (unable to verify 11/23)
INSTINCT	Infrastructure for Noise and Soundscape Tolerant Investigation of Nonspecific Call Types
INT	Office of International Affairs (DOI)
INTEGRAL	International Gamma-ray Astrophysics Laboratory
IntELiMon	Interagency Ecosystem LiDAR Monitoring
INTERPOL	International Criminal Police Organization
INV	Investigations Directorate
INVEST	Infrastructure Voluntary Evaluation Sustainability Tool
INVNT	CBP Innovation Team
IO	Bureau of International Organization Affairs \| International Office
IOC/AG	Information Operations Center’s Analysis Group (unable to verify 2/17)
IOCM	Integrated Ocean and Coastal Mapping
IOD	Indexing on Demand \| Intelligence Oversight Directorate \| International Operations Division
IOLP	Inventory of Owned and Leased Properties
IOMs	Internet Only Manuals
IOOC	Interagency Ocean Observation Committee
IOOS	Integrated Ocean Observing System
IOS	Division of Integrative Organismal Systems
IOSS	Interagency OPSEC Support Staff (decommissioned 12/22) \| Investigative and Operations Support Section (unable to verify 8/22)

IP	Intellectual Property Section \| Office of Infrastructure Protection (changed to ISD)
IPA	Industrial Policy and Analysis
IPaC	Information for Planning and Consultation (changed from Information, Planning, and Conservation)
IPAD	International and Philanthropic Affairs Division \| International Production Assessment Division
IPAS	Illicit Pathways Attack Strategy
IPAWS	Integrated Public Alert & Warning System
IPB	Inspection Policy Branch
IPC	Infrastructure Perception and Control \| Integrated Partnership and Communication \| International Programs Center
IPCA	International Parental Child Abduction
IPCD	Intermodal Passenger Connectivity Database
IPD	Innovative Program Delivery (changed to CIFS) \| International Programs Division (unable to verify 11/22)
IPDD	Institutional Programs Development Division
IPE	Immunization Program Evaluation
IPEC	Intellectual Property Enforcement Coordinator (unable to verify 2/25)
IPEDS	Integrated Postsecondary Education Data System
IPEF	Indo-Pacific Economic Framework for Prosperity
IPEMF	Integrated Physical and Ecological Modeling and Forecasting
IPEP	Intellectual Property Theft Enforcement Program
IPG	Industry Proving Grounds
IPHIS	Integrated Plant Health Information System
IPI	Bureau for Inclusive Growth, Partnerships, and Innovation (unable to verify 2/25) \| International and Philanthropic Innovation (changed to IPAD)
IPIF	Institute of Pacific Islands Forestry
IPL	Intergovernmental Public Liaison
IPM	Integrated Pest Management, FWS (unable to verify 2/16) \| Integrated Pest Management, NIFA
IPO	International Policy Office
IPP	Import Permit Program \| Innovative Partnerships Program (changed to ITPO) \| Unmanned Aircraft System Integration Pilot Program \| Invoice Processing Platform
IPR	Interatomic Potentials Repository
IPR Center	National Intellectual Property Rights Coordination Center
IPRCC	Interagency Pain Research Coordinating Committee
IPRiS	Intellectual Property Rights Internal Search System
IPRL	Invasive Plant Research Laboratory
IPRP	Interagency Pain Research Portfolio
IPRR	Intellectual Property Rights e-Recordation Online System
IPRS	Intellectual Property Rights Search
IPS	Images and Publications System, NCEI
IPTF	Intellectual Property Task Force (unable to verify / website archived 1/22)
IPTU	International Prisoner Transfer Program
IPV	Intimate Partner Violence
IPY	International Polar Year
IQCP	Individualized Quality Control Plan
IQIP	Immunization Quality Improvement for Providers

IRA	Industry and Regional Analysis Division (unable to verify 10/19)
IRAC	Interdepartment Radio Advisory Committee
IRAP	International Research and Applications Project (unable to verify 9/23)
IRAS IWG	Intelligent Robotics and Autonomous Systems Interagency Working Group
IRAT	Influenza Risk Assessment Tool \| Inorganic and Radiation Analytical Toxicology Branch
IRB	Internal Revenue Bulletin
IRDA	Informatics Research and Development Activity (unable to verify 6/14; likely replaced by DHIS)
IREMS	Integrated Real Estate Management System
IRENE	Image, Reconstruct, Erase Noise, Etc.
IREPO	Institutional Resilience and Expanded Postsecondary Opportunity program
IRFMS	Integrated Rangeland Fire Management Strategy
IRG	Intergovernmental Reference Guide
IRIS	Immigration Records and Identity Services Directorate \| Industrial Research and Development Information System (unable to verify 11/18) \| Integrated Risk Information System \| Interface Region Imaging Spectrograph
IRM	Bureau of Information Resource Management (changed to DT) \| Internal Revenue Manual
IRMA	Integrated Resource Management Applications
IRMAA	Income-Related Monthly Adjustment Amount
IRMCO	Interagency Resources Management Conference (unable to verify 3/13)
IROC	Interagency Resource Ordering Capability
IRP	Integrated Resource Planning \| Intermediary Relending Program \| Intramural Research Program
IRPF	Infrastructure Resilience Planning Framework
IRR	Indian Reservation Roads (replaced by TTP)
IRS	Indian Resources Section (changed to Tribal Resources Section) \| Internal Revenue Service
IRS-CI	Internal Revenue Service, Criminal Investigations
IRSOB	IRS Oversight Board (unable to verify 4/22)
IRTM	Division of Information Resources and Technology Management
IRVS	Integrated Rapid Visual Screening for Buildings (page archived)
IRWIN	Integrated Reporting of Wildland-Fire Information

IS	International Services
ISA	Importer Self-Assessment
ISAs	Integrated Science Assessments
ISAC	Invasive Species Advisory Committee
ISAT	Impervious Surface Analysis Tool \| Information Sharing Assessment Tool (page archived)
ISB	Immunization Systems Branch \| Investigative Services Branch
ISC	Integrated Support Center (changed to CSC) \| Interagency Securities Council \| Interagency Security Committee
ISC3	Implementation Science Centers in Cancer Control
ISCAP	Interagency Security Classification Appeals Panel
ISCD	Infrastructure Security Compliance Division (changed to Chemical Security)
ISCR	Institute for Scientific Computing Research (unable to verify 2/19)
ISD	Division of Indian Self-Determination \| Immunization Services Division \| Industry Safety Data \| Information Services Division \| Infrastructure Security Division \| Integrated Surface Database (replaced by GHCNh)
ISDC	Interagency Suspension and Debarment Committee
ISE	Information Sharing Environment (unable to verify 8/22)
ISEP	Indian School Equalization Program
ISF	Importer Security Filing
ISGM	Impervious Surface Growth Model
ISIS	Integrated Software for Imagers and Spectrometers
ISLSWG	International Space Life Sciences Working Group (unable to verify 10/23)
ISMICC	Interdepartmental Serious Mental Illness Coordinating Committee
ISMN	International Standard Music Number
ISN	Bureau of International Security and Nonproliferation
ISN/ECC	Office of Export Control Cooperation (also, ECC)
ISN/MNSA	Office of Multilateral Nuclear and Security Affairs (also, MNSA)
ISO	Immunization Safety Office \| Office of International Security Operations (unable to verify 6/19)
ISOO	Information Security Oversight Office
ISP	International Statistics Program
ISPO	International Safeguards Project Office
ISRU	In-Situ Resource Utilization
ISS	International Space Station
ISSM	Ice Sheet System Model
ISSMG	Internet and Scalable Systems Metrology Group
IST	Infrastructure Survey Tool \| Investigative Support Team
ISTAND	Innovative Science and Technology Approaches for New Drugs
I-STEP	Intermodal Security Training and Exercise Program

ITA	Injury Tracking Application \| Interactive Tax Assistant \| International Trade Administration
ITAP	Federal Interagency Committee on Invasive Terrestrial Animals and Pathogens \| International Technical Assistance Program
ITAR	International Traffic in Arms Regulations
ITC	International Tax Counsel \| International Technical Cooperation \| NRCS Information Technology Center (unable to verify 11/22) \| United States International Trade Commission
ITCCH	Intramural Targeted Climate Change and Health (unable to verify 2/25)
ITCR	Informatics Technology for Cancer Research
ITD	International Trade Division (changed to IAD)
ITDS	International Trade Data Systems
ITEC	Interagency Trade Enforcement Center (replaced by ICTIME)
ITF	Infrastructure Task Force \| Innovation Task Force
ITIL	Interdiction Technology and Integration Laboratory
ITIS	Integrated Taxonomic Information System
ITK	Information, Translation, and Knowledge-Delivery
ITL	Information Technology Laboratory
ITPO	Innovative Technology Partnerships Office (changed to SPO)
ITR	Innovation, Technology, and Research (unable to verify 2/25)
ITRDB	International Tree-Ring Data Bank
i-Tree	Individual Trees
ITS	Identity Theft Supplement \| Institute for Telecommunications Sciences \| Intelligent Transportation Systems \| International Treasury Services
ITVERP	International Terrorism Victim Expense Reimbursement Program
IUU	Illegal, Unreported, and Unregulated Fishing
IV	Immigrant Visa
IV&V	Katherine Johnson Independent Verification and Validation Facility
IVIS	Immigrant Visa Information System (pdf)
IVLP	International Visitor Leadership Program
IVO	Immigrant Visa Overseas (pdf)
IVP	International Visitors Program
IVY	Investigating Respiratory Viruses in the Acutely Ill
IWAAs	Integrated Water Availability Assessments
iWARM	Individual Waste Reduction Model
IWC	Irregular Warfare Center
IWCAL	Integrated Water Chemistry Assessment Laboratory
IWCG	Integrated Water Cycle Group
IWG	Interagency Working Group
IWG-FI	Interagency Working Group on Facilities and Infrastructure
IWG-OCM	Interagency Working Group on Ocean and Coastal Mapping
IWG-OEC	Interagency Working Group on Ocean Exploration and Characterization
IWGOA	Interagency Working Group on Ocean Acidification
IWGYP	Interagency Working Group on Youth Programs (unable to verify 2/25)
IWM	Office Integrated of Waste Management (unable to verify 6/24)
IWMS	Irrigation and Water Management Survey
IWRSS	Integrated Water Resources Science and Services
IWS	Irregular Warfare Support Program (unable to verify; likely changed to CTTSO)
IWTSD	Irregular Warfare Technical Support Directorate
IXPE	Imaging X-ray Polarimetry Explorer
IYFC	Institute of Youth, Family, and Community
IYSC	Indian Youth Service Corps Program