Refresh 33 was supposed to land in September. GSA pushed it to October, which buys you a few weeks to read it properly.
MAS Refresh 33 is GSA’s next update to the Multiple Award Schedule solicitation. Based on GSA’s advance notice, it adds supply chain security terms under the Revolutionary GSAR Overhaul, bars product substitution without the buyer’s written approval, widens FASt Lane eligibility beyond IT, and updates Service Contract Labor Standards wage determinations. Existing contractors bring those changes into their contracts by accepting a Mass Modification.
When Is MAS Refresh 33 Being Released?
GSA planned Refresh 33 for September 2026, held a preview webinar on September 1, and then moved the release to October 2, 2026 so the changes could be fully integrated. The Mass Mod to existing contracts follows the solicitation refresh.
What Changes in Refresh 33?
Five changes, based on the advance notice. Some affect every contractor; others only touch specific SINs.
Supply chain security requirements
Refresh 33 brings supply chain protections into MAS contracts through GSAR Part 540, part of GSA’s Revolutionary GSAR Overhaul. Expect new clause language on how you source and protect what you sell to the government.
Product substitution without written approval ends
This is the change most likely to catch product sellers off guard. Under Refresh 33, a contractor can’t substitute a product on an order without the buyer’s prior written approval. An approved substitute must already be on your MAS contract, and it can’t cost more than the original unless the customer agrees to the higher price.
If your fulfillment team swaps in an equivalent item when stock runs short, that habit needs a written-approval step before Refresh 33 takes effect. A Schedule management review can build that step into your order process so it holds up in an audit.
FASt Lane expands beyond IT
FASt Lane, GSA’s expedited review path, has been limited to IT. Refresh 33 extends new-offer eligibility to every MAS Large Category when federal customer demand is documented. Expedited modifications stay limited to IT.
Updated SCLS wage determinations
Refresh 33 incorporates the most recent Service Contract Labor Standards wage determinations. Service contractors should check that the labor rates they pay on covered work still meet the updated minimums.
SIN-level changes
The advance notice lists clarifications for roofing services, temporary structures, installation services, employee relocation and travel agent services. If you hold any of those SINs, read the SIN descriptions in the refreshed solicitation line by line.
What Should I Check Before Accepting the Refresh 33 Mass Mod?
Match each change to your contract and your operations before you sign. This checklist covers the advance-notice items.
| Change | Who it affects | Check before signing |
|---|---|---|
| Supply chain security (GSAR Part 540) | All contractors, especially product sellers | Read the new clause text and compare it to how you source and track products today |
| Product substitution rule | Product sellers and resellers | Add a written buyer-approval step to fulfillment; confirm substitutes are on your contract |
| FASt Lane expansion | New offerors outside IT | Document agency demand if you plan to submit a new offer |
| SCLS wage determinations | Service contractors on covered work | Compare the wages you pay to the updated determinations |
| SIN clarifications | Roofing, temporary structures, installation, relocation, travel | Reread your SIN descriptions and confirm your offerings still fit |
Do I Have to Accept the Refresh 33 Mass Mod?
In practice, yes, if you want your contract to stay current. Each Refresh Mass Mod comes with an acceptance window, reported at about 30 days for Refresh 33.
Falling behind on Mass Mods creates problems later. Pending Mass Mods can hold up other modifications you need, and a contract that’s several Refreshes behind draws attention at option time. Accept on time, but read first.
Does Refresh 33 Affect Service Contractors, or Only Product Sellers?
Both. Product sellers feel the substitution rule and supply chain terms most. Service contractors on covered work feel the SCLS wage updates, and service SINs such as installation, employee relocation and travel agent services get clarifications of their own.
Our Take
A Mass Mod is a contract change, not paperwork. The substitution rule alone turns a common fulfillment habit into a compliance issue the day you sign. Contractors who read Refresh 33 against their own operations will accept it without surprises; contractors who sign it to clear the notification will find out what changed from a customer or an auditor.
Frequently Asked Questions
When is MAS Refresh 33 being released?
GSA moved the release from September to October 2, 2026. The Mass Mod to existing contracts follows the refreshed solicitation.
Do I have to accept the Refresh 33 Mass Mod?
Yes, if you want your contract to stay current. Each Mass Mod has an acceptance window, reported at about 30 days for Refresh 33, and falling behind can hold up other modifications.
Can I send a different product if the one on a GSA order is out of stock?
Not without the buyer’s prior written approval under Refresh 33. The substitute must already be on your MAS contract and can’t cost more unless the customer agrees.
What is GSAR Part 540?
It’s the part of GSA’s regulation that Refresh 33 uses to bring supply chain security requirements into MAS contracts, as part of the Revolutionary GSAR Overhaul.
Does Refresh 33 affect service contractors?
Yes. It updates SCLS wage determinations and clarifies several service SINs, including installation, employee relocation and travel agent services.
Sign Refresh 33 Knowing Exactly What Changed in Your Contract
Signing a Mass Mod without reading it doesn’t save time. It moves the reading to the worst possible moment: an audit finding, a rejected substitution or a wage complaint. We’ll review Refresh 33 against your contract, your SINs and how you actually fulfill orders before you accept it.
→ Start Your Refresh 33 Mass Mod Review
An hour of reading now beats a year of explaining later.
