The transition from legacy OASIS to OASIS+ is complete. All new professional services task orders must now go through OASIS+, GSA's replacement vehicle for one of the most widely used professional services GWACs in the federal government. The official OASIS and OASIS Small Business program page remains the authoritative reference, and GSA's contract team can be reached directly at [email protected] for ordering questions and vehicle guidance.
When Legacy OASIS Ended: Key Dates
The shutdown of legacy OASIS was not a single event — it unfolded in stages across late 2024 and early 2025, and contractors who were not tracking those dates may still be operating under misconceptions about what vehicles remain available.
The legacy OASIS Small Business and 8(a) ordering periods closed on December 19, 2024. This was the earlier of the two sunset dates, meaning agencies could no longer issue new task orders against those small business and 8(a) pools after that date. The legacy OASIS Unrestricted ordering period followed on March 1, 2025. Together, these two dates mark the formal end of new OASIS ordering activity across all pools.
The Symphony task order management system, which agencies used to manage legacy OASIS task orders, also shut down — on February 28, 2025. Agencies with existing task orders in performance were transitioned to alternative management mechanisms; those task orders in performance continue unaffected through their individual periods of performance. The performance of an existing task order is not disrupted by the vehicle's ordering period closure. But no new task orders — including options not yet exercised — can be issued against the legacy vehicles.
The legacy OASIS structure that preceded the transition was substantial in scope. It encompassed six unrestricted pools, six small business pools, and five 8(a) pools — 17 pools in total — covering 28 NAICS codes plus six exceptions. There was no program ceiling. That breadth explained why OASIS was so heavily used: it covered an enormous swath of professional services work from a single contract family.
What OASIS+ Covers: Core Service Categories
OASIS+ carries forward the professional services mission of legacy OASIS with a structure designed for the current market. The vehicle covers six core service categories: program management, management consulting, logistics, engineering, scientific, and financial services. These categories encompass a wide range of disciplines — environmental engineering, management consulting, research and development support, supply chain services, financial analysis, and more.
A critical distinction: OASIS+ is not an IT GWAC. Its scope is professional services in the broadest sense. This is where the comparison to Alliant 3 becomes important for contractors designing their vehicle strategy. Alliant 3, launched in March 2026 with OMB preferred vehicle designation, covers the full IT services lifecycle — but it does not cover the professional services disciplines that OASIS+ handles. The two vehicles are designed to complement each other. A federal agency building a new data analytics program, for example, might use Alliant 3 for the IT development work and OASIS+ for the management consulting and program management support.
This distinction also matters when agencies are scoping requirements. Contracting officers writing performance work statements should carefully map their requirements to the vehicle that governs the preponderant scope of work. Mixing IT and professional services on a single task order requires vehicle selection based on the predominant work, and that analysis has real consequences for which awardee pool receives the fair opportunity solicitation.
How OASIS+ Differs from Legacy OASIS in Practice
Contractors who held legacy OASIS contracts and won task orders under the old vehicle need to understand both the continuity and the change. On the continuity side: existing task orders in performance continue. Revenue from work awarded under legacy OASIS does not stop because the vehicle's ordering period closed. Contracting officers continue administering those task orders normally, and awardees continue performing and invoicing against them.
On the change side: any new requirement, any new task order solicitation, and any new competition must go through OASIS+. A program office that ran a successful IDIQ task order under legacy OASIS Unrestricted and wants to follow on with a new requirement has only one path: OASIS+ or another appropriate vehicle. There is no mechanism to issue new work under legacy OASIS structures post-ordering period closure.
OASIS+ is live and accepting orders. GSA has built the vehicle to accommodate the full range of professional services acquisitions that legacy OASIS handled, and agencies have been migrating their professional services pipelines to the new vehicle since it went live. The transition is not a disruption in professional services contracting so much as a vehicle handoff — the work continues, the awardee community has shifted, and the procedures have been updated.
What It Means for Contractors
If you held a legacy OASIS contract but did not win a position on OASIS+, your competitive access to new GSA OASIS-channeled professional services work is gone until and unless a future on-ramp opens. This is a significant loss of market access for firms that built pipeline strategies around legacy OASIS. The priority for those firms now is to secure alternative vehicles — MAS Professional Services, agency-specific IDIQs, or other GWACs with relevant NAICS coverage.
If you hold an OASIS+ contract, the vehicle is now the primary professional services acquisition pathway for federal agencies that previously relied on legacy OASIS. That translates to task order opportunity volume that is concentrated across a smaller awardee pool than the legacy vehicle's expansive pool structure. Firms with OASIS+ positions should be actively engaged with agency contacts, monitoring procurement forecasts, and ensuring their company information in GSA's systems accurately reflects their current capabilities and key personnel.
For agencies, the practical guidance is straightforward: contact [email protected] for ordering assistance, consult the program office for scope determinations, and do not attempt to issue new work against legacy OASIS vehicles — those ordering periods are closed. Any acquisition professional who receives a task order package routed to a legacy OASIS vehicle after March 1, 2025 has received a document with an error that must be corrected before award.
The complementary relationship between OASIS+ and Alliant 3 is worth internalizing at the portfolio level. Contractors who hold positions on both vehicles are positioned to pursue the widest range of federal services work — IT on Alliant 3, professional services on OASIS+, with the two vehicles covering between them nearly the entire scope of complex services contracting that GSA facilitates on a governmentwide basis.
