The GSA MAS compliance glossary.
Plain-English definitions of the acronyms, clauses, and systems you will hit as a MAS contractor under Refresh 31. Written by federal-acquisition professionals, not by a marketing team.
A909 — Mass Mod A909
The system-generated MAS contract modification GSA issues under Refresh 31 to move non-TDR contracts onto mandatory monthly Transactional Data Reporting for every MAS SIN. The Refresh 31 solicitation changes — the new AI-related clauses reflecting OMB M-25-22 and the updated pricing-related obligations — are carried by the separate refresh modification, Mass Mod A914.
Why it mattersContractors have a 60-day acceptance window. Miss it and your contract can be suspended and removed from GSA Advantage, eLibrary, and eBuy. On-time acceptors (by June 30, 2026) begin monthly TDR reporting July 1, 2026; late acceptors begin October 1, 2026. See the TDR Guide for the specific field changes.
CAV — Contractor Assistance Visit
A structured review conducted by a GSA Industrial Operations Analyst (IOA) who examines a MAS contractor's records and Schedule-compliance practices. The IOA covers sales reporting, clause compliance, pricing practices, and catalog accuracy.
Why it mattersA CAV can produce corrective-action requirements, TDR adjustments, or — in severe cases — contract cancellation. Contractors with poor record-keeping, mismatched SIN assignments, or undocumented price reductions find CAVs painful. Preparation is most of the game.
eMod
GSA's electronic system for submitting post-award contract modifications — price changes, SIN additions or deletions, catalog updates, administrative changes (address, point-of-contact, UEI), and the 23+ other modification types recognized by GSA.
Why it mattersModifications that don't match GSA's expected structure or lack the right documentation get rejected. Rejection resets your clock and usually means lost revenue while the contract is out of sync with reality.
eOffer
GSA's electronic system for preparing and submitting a new MAS offer. An eOffer package includes SIN selections, pricing, the FCP catalog, representations and certifications, and corporate experience narratives. Under Refresh 31, the Commercial Sales Practices (CSP-1) disclosure is no longer required as part of the package.
Why it matterseOffer submissions fail more often for package-structure errors than for substantive pricing issues. Assembly discipline is the difference between a 90-day and a 9-month evaluation cycle.
FAR — Federal Acquisition Regulation
The primary regulation governing acquisitions by U.S. federal executive agencies. FAR is the master document that GSAM, DFARS, and agency supplements layer on top of.
Why it matters for MAS contractorsThe contractor's TDR and IFF certification obligations flow from the GSAR clauses GSAR 552.216-75 (Transactional Data Reporting) and GSAR 552.238-80 (Industrial Funding Fee and Sales Reporting) — which is why every MAS Pilot export is framed as "for contractor review and certified submission." FAR Part 8 (Required Sources of Supplies and Services) governs how ordering activities buy from the Schedules. Other FAR provisions you'll cross: FAR 4.703 (contractor records retention) and FAR 52.204-21 (basic safeguarding).
GSA — General Services Administration
The federal agency that manages the Multiple Award Schedule program and administers MAS contracts on behalf of the federal government. GSA's Federal Acquisition Service (FAS) is the unit most MAS contractors interact with day to day.
Why it mattersGSA issues Refresh updates, administers Mass Mods like A909, runs the SRP, conducts CAVs, and cancels contracts for non-compliance. Understanding whose desk your paperwork lands on — Contracting Officer, IOA, or Pricing Analyst — speeds most problems.
GSAM — GSA Acquisition Manual
GSA's supplement to the FAR. Where the FAR gives a government-wide baseline, the GSAM provides the GSA-specific overlay.
Why it mattersKey MAS provisions for Schedule holders live in the GSAM and in the GSAR (GSA Acquisition Regulation): GSAM 538.270 (Security Safeguarding), GSAM 538.7104 (Representations), and the TDR clause itself — GSAR 552.238-80. If a proposal or modification cites only FAR without the GSAM overlay, it's incomplete for MAS.
IFF — Industrial Funding Fee
A fee MAS contractors remit to GSA, calculated as a percentage of total MAS sales for the reporting period. The current IFF rate is 0.75%. It is calculated monthly and remitted quarterly via Pay.gov.
Why it mattersContractors remain responsible for applying the IFF rate GSA has in effect for each reporting period and certifying the calculation under GSAR 552.238-80. The most common Wave-1 finding across MAS Pilot testing wasn't a missing TDR field — it was an IFF calculation that had been wrong for months.
MAS — Multiple Award Schedule
GSA's government-wide procurement vehicle that establishes long-term contracts with commercial vendors so that federal agencies (and, in some cases, state and local governments) can buy commercial products and services at pre-negotiated prices and terms.
Why it mattersThe MAS program is the single largest source of commercial-goods-and-services revenue for federal sellers — a $45B+ market. Holding a MAS contract means you've been vetted; losing one usually means starting over.
Pay.gov
The U.S. Treasury portal through which MAS contractors remit their quarterly IFF payments. Supports ACH and card (within limits).
Why it mattersA late or missed Pay.gov remittance is a compliance event that shows up in your GSA record. Pay.gov's ID and reference fields matter — a remittance with the wrong contract number is the same as no remittance from GSA's perspective until you reconcile.
PRC — Price Reductions Clause
The legacy pricing-compliance mechanism that required MAS contractors to track and report price reductions granted to a commercial Most Favored Customer (MFC) or other designated-category customers, and to pass equivalent reductions through to GSA.
Why it mattersPRC has been the source of some of the largest MAS audit liabilities in the program's history. Contractors accepting TDR are no longer subject to PRC — which is one of the main reasons contractors opt into TDR voluntarily, and why Refresh 31's mandatory-TDR move is actually a simplification for most.
Refresh 31
The GSA Multiple Award Schedule contract refresh (issued via Mass Mod A914) that made TDR mandatory for every MAS SIN — through the separate system-generated Mass Mod A909 — added new AI-clause requirements reflecting OMB M-25-22, and updated EPA (Economic Price Adjustment) documentation rules.
Why it mattersRefresh 31 is the most significant MAS refresh in a decade. Timeline: April 2, 2026 A909 issued with 60-day clock; Jul 1, 2026 reporting begins for on-time acceptors; Oct 1, 2026 for late acceptors; Jan 1, 2027 enforcement begins (grace period ends Dec 31, 2026).
SAM.gov
The U.S. government's entity-registration system. MAS contractors must maintain an active SAM.gov registration — with valid UEI, banking details, NAICS codes, and representations — to receive federal awards and remain eligible under their MAS contract.
Why it mattersLapsed SAM registration is a silent killer. GSA pulls contractor status from SAM for eligibility checks; a lapsed registration effectively takes you off the Schedule until you update and the system syncs.
SIN — Special Item Number
An alphanumeric code (e.g., 54151S, OS4) GSA uses to categorize the products and services sold under a MAS contract. Every MAS line item is assigned to at least one SIN. Under Refresh 31, SINs are also the unit at which TDR mandatory status is applied.
Why it mattersThe SIN is reported with every TDR record. A mismatched SIN assignment — item sold under the wrong SIN — is one of the most common CAV findings and one of the most frequent TDR rejection codes.
SRP — Sales Reporting Portal
GSA's system for accepting monthly TDR data uploads and quarterly IFF remittances. SRP accepts pipe-delimited flat-file submissions matching the TDR schema GSA defines. Submissions that fail SRP validation are returned with rejection codes that must be corrected and resubmitted.
Why it mattersSRP's rejection messages are often cryptic and reference internal field numbers rather than human names. Contractors without an upstream validator end up cycling rejections for weeks. Checking every required field before SRP sees it is the entire reason TDR Guard exists.
TAA — Trade Agreements Act
A statute governing country-of-origin restrictions for federal procurement. MAS contractors must ensure that end products sold under a MAS contract originate in the U.S. or a designated country (Canada, Mexico, Japan, most EU member states, and others). Products from non-designated countries are generally prohibited from sale under a MAS contract.
Why it mattersTAA violations surface frequently in CAVs. Country of Origin is not a TDR field GSA requires, but MAS Pilot uses it as a cross-check because a TAA violation can invalidate the whole transaction regardless of whether the TDR submission was technically correct.
TDR — Transactional Data Reporting
The GSA MAS reporting requirement under GSAR 552.216-75 that obligates Schedule holders to report line-item sales data monthly to GSA via the Sales Reporting Portal; the related Industrial Funding Fee and sales-reporting obligation is set by GSAR 552.238-80. TDR replaces the Price Reductions Clause (PRC) for participating contractors.
Why it mattersTDR consists of 11 core data elements plus expanded fields GSA phases in — covering both Products and Services profiles. Under Refresh 31, TDR is mandatory for every MAS SIN. See the full TDR Guide for field-by-field requirements and common rejection reasons.
UOM — Unit of Measure
A code that expresses how an item is quantified — EA for each, HR for hour, LB for pound, BX for box, etc.
UOM is one of the required TDR data elements. GSA maintains an accepted-codes list; anything outside that list is rejected at SRP. A common error: using a custom catalog UOM that works internally but fails GSA's validator.
Take the glossary further.
The TDR Compliance Guide walks through each required field and SRP submission step in depth. If you're a Schedule holder navigating Refresh 31, the Wave 3 waitlist is where early-access contractors get evaluated.