This report is part of a suite of reports that discuss appropriations for the Department of Homeland Security (DHS) for FY2017. It specifically discusses appropriations for the components of DHS included in the fourth title of the homeland security appropriations bill—in past years, this has been U.S. Citizenship and Naturalization Services (USCIS), the Federal Law Enforcement Training Center (FLETC), the Science and Technology Directorate (S&T), and the Domestic Nuclear Detection Office (DNDO). In FY2017, the Administration proposed moving the Domestic Nuclear Detection office into a new Chemical, Biological, Radiological, Nuclear, and Explosives Office (CBRNEO), along with several other parts of DHS. Congress has labeled this title of the bill in recent years as "Research and Development, Training, and Services." The report provides an overview of the Administration's FY2017 request for Research and Development, Training, and Services, and the appropriations proposed by the Senate and House appropriations committees in response. Rather than limiting the scope of its review to the fourth title of the bills, the report includes information on provisions throughout the bills and report that directly affect these components. The suite of CRS reports on homeland security appropriations tracks legislative action and congressional issues related to DHS appropriations, with particular attention paid to discretionary funding amounts. The reports do not provide in-depth analysis of specific issues related to mandatory funding—such as retirement pay—nor do they systematically follow other legislation related to the authorization or amending of DHS programs, activities, or fee revenues. Discussion of appropriations legislation involves a variety of specialized budgetary concepts. The Appendix to CRS Report R44621, Department of Homeland Security Appropriations: FY2017 explains several of these concepts, including budget authority, obligations, outlays, discretionary and mandatory spending, offsetting collections, allocations, and adjustments to the discretionary spending caps under the Budget Control Act ( P.L. 112-25 ). A more complete discussion of those terms and the appropriations process in general can be found in CRS Report R42388, The Congressional Appropriations Process: An Introduction , by Jessica Tollestrup and James V. Saturno, and the Government Accountability Office's A Glossary of Terms Used in the Federal Budget Process . Except in summary discussions and when discussing total amounts for the bill as a whole, all amounts contained in the suite of CRS reports on homeland security appropriations represent budget authority and are rounded to the nearest million. However, for precision in percentages and totals, all calculations were performed using unrounded data. Data used in this report for FY2016 amounts are derived from two sources. Normally, this report would rely on P.L. 114-113 , the Omnibus Appropriations Act, 2016—Division F of which is the Homeland Security Appropriations Act, 2016—and the accompanying explanatory statement published in Books II and III of the Congressional Record for December 17, 2015. However, due to the implementation of the Common Appropriations Structure for DHS (see below), additional information is drawn from H.Rept. 114-668 , which presents the FY2016 enacted funding in the new structure. H.Rept. 114-668 also serves as the primary source for the FY2016 enacted funding levels, the FY2017 requested funding levels, and the House Appropriations Committee recommendation in the new structure. S.Rept. 114-264 serves as the primary source for the FY2016 enacted funding levels, the FY2017 requested funding levels, and Senate Appropriations Committee recommendation in the "legacy structure"—the overall structure of appropriations enacted for FY2016. The two appropriations committees took different approaches not only with the Common Appropriations Structure, but also with the Administration's proposed establishment of the new Chemical, Biological, Radiological, Nuclear, and Explosives Office—the Senate Appropriations Committee rejected the reorganization, while the House did not. Readers should bear that in mind while making comparisons of funding levels for DNDO or CBRNEO, or funding comparisons by title of the bill. Section 563 of Division F of P.L. 114-113 (the FY2016 Department of Homeland Security Appropriations Act) provided authority for DHS to submit its FY2017 appropriations request under the new common appropriations structure (CAS), and implement it in FY2017. Under the act, the new structure was to have four categories of appropriations: Operations and Support; Procurement, Construction, and Improvement; Research and Development; and Federal Assistance. Most of the FY2017 DHS appropriations request categorized its appropriations in this fashion. The exception was the Coast Guard, which was in the process of migrating its financial information to a new system. DHS has also proposed realigning its Programs, Projects, and Activities (PPA) structure—the next level of funding detail below the appropriation level—possibly trying to align PPAs into a mission-based hierarchy. The House Appropriations Committee made its funding recommendation using the CAS (although it chose to implement it slightly differently than the Administration had envisioned in Title I), but the Senate Appropriations Committee did not, instead drafting its annual DHS appropriations bill and report using the same structure as was used in FY2016. It remains to be seen how differences between the House and Senate structures will be worked out in the legislation which finalizes FY2017 appropriations levels for DHS. Some individual programmatic comparisons are possible between the two bills, and the Coast Guard's appropriations are comparable as its FY2017 funding was not proposed in the CAS structure. However, no authoritative crosswalk between the House Appropriations Committee proposal in the CAS structure and Senate Appropriations Committee proposal in the legacy structure is publicly available. Generally, the homeland security appropriations bill includes all annual appropriations provided for DHS, allocating resources to every departmental component. Discretionary appropriations provide roughly two-thirds to three-fourths of the annual funding for DHS operations, depending how one accounts for disaster relief spending and funding for overseas contingency operations. The remainder of the budget is a mix of fee revenues, trust funds, and mandatory spending. Appropriations measures for DHS typically have been organized into five titles. The first four are thematic groupings of components: Departmental Management and Operations; Security, Enforcement, and Investigations; Protection, Preparedness, Response, and Recovery; and Research and Development, Training, and Services. A fifth title contains general provisions, the impact of which may reach across the entire department, impact multiple components, or focus on a single activity. The following pie chart presents a visual comparison of the share of annual appropriations requested for the components funded in each of the first four titles, highlighting the components discussed in this report. The Research and Development, Training, and Services (Title IV) of the DHS appropriations bill is the second smallest of the four titles that carry the bulk of the funding in the bill. In FY2016, Title IV included USCIS, FLETC, DNDO, and S&T. The Administration requested $1.63 billion in FY2017 net discretionary budget authority for components included in this title, as part of a total budget for these components of $5.52 billion for FY2017. The appropriations request was $133 million (8.9%) more than was provided for FY2016. Part of the reason for the requested growth in Title IV was the inclusion of the Administration's newly proposed CBRNEO in this title, which incorporated DNDO, as well as the Office of Health Affairs and part of the National Protection and Programs Directorate from Title III, and part of the Office of Policy from Title I. Together, this represented a transfer of components funded at over $140 million in FY2016 in other titles of the bill into Title IV. Senate Appropriations Committee-reported S. 3001 would have provided the components included in this title $1.50 billion in net discretionary budget authority. This would have been $132 million (8.1%) less than requested, and less than $1 million (<0.1%) more than was provided in FY2016. It did not include the reorganization to form CBRNEO, or funding for the new office. House Appropriations Committee-reported H.R. 5634 would have provided the components included in this title $1.63 billion in net discretionary budget authority. This would have been $1 million (0.1%) more than requested, and $134 million (9.0%) more than was provided in FY2016. The House bill included funding for the new CBRNEO. These bills were not voted on in either body, and no annual appropriations bill for DHS was enacted prior to the end of FY2016. On September 29, 2016, the President signed into law P.L. 114-223 , which contained a continuing resolution that funds the government at the same rate of operations as FY2016, minus 0.496%, through December 9, 2017. A second continuing resolution was signed into law on December 10, 2016 ( P.L. 114-254 ), funding the government at the same rate of operations as FY2016, minus 0.1901%, through April 28, 2017. For details on the continuing resolution and its impact on DHS, see CRS Report R44621, Department of Homeland Security Appropriations: FY2017 . Table 1 lists the enacted funding level for the individual components funded under the Research and Development, Training, and Services title for FY2016, as well as the amounts requested for these accounts for FY2017 by the Administration, and proposed by the Senate and House appropriations committees. The table includes information on funding under Title IV as well as other provisions in the bill. Three activities dominate the work of the U.S.