Modifications and Mass Modification Guidance

The clauses below outline the different types of modifications that will happen throughout the life of your contract. The main difference between modifications and mass modifications is that modifications are generally initiated by you, while mass modifications are those routinely generated by GSA and often associated with a solicitation refresh. These two types of modifications are used to keep your contract current and compliant.

Mass Modifications

MAS Mass Modifications are issued directly to contractors via the mass mod system. Mass Mods should be signed within 90 days of receipt. Each mass modification will outline the significant changes impacting the solicitation and your subsequent contract. Significant changes may vary depending on the offerings on your contract. If you do not sign a mass modification prior to the next modification release, the unsigned mass mod changes will roll into the new Refresh mass mods. In other words, if you have not signed Refresh 2 by the time Refresh 3 is released, when you sign Refresh 3 it will include changes from Refresh 2 and 3.

Here is a breakdown of the significant changes associated with the MAS Solicitation Refresh Mass Modifications:

FY 21 MAS Refresh Significant Changes [PDF - 93 KB]

Contractor Initiated Modifications

Key component: Understand when you need to initiate a modification for your Schedule and when GSA will initiate modifications that may impact your Schedule.


  • Review the following MAS solicitation clauses:
    • 552.238-82 Modifications (Federal Supply Schedule) (Jan 2022) (Alternate I - MAR 2020)
    • 552.238-82 Modifications (Federal Supply Schedule) (Jan 2022) (Alternate II - MAY 2019)
  • GSA has developed a single MAS modification guidance, along with Price Proposal Templates. This guidance includes all modification types available in eMod and is meant to ensure that contractors are aware of the information needed to successfully prepare and submit modification requests to their Contracting Officer/Contracting Specialist (CO/CS). Please click below to download the MAS modification guidance and Price Proposal Templates.
  • A modification is required whenever a change is made to your Schedule contract. Most frequently, changes are made to products and/or services, prices, or terms and conditions. However, modifications are also required for administrative changes such as authorized negotiators, address(es), phone/fax numbers, and key personnel. When initiated by the contractor, modification requests must be submitted electronically using eMod by your company’s Contracting Administrator, often referred to as the Point of Contact (POC). For information specific to your Schedule, please visit the Vendor Support Page, "Modification Options".

    Should your firm need to modify your contract, please check your GSA Schedule Offerings page to make sure you are not missing any specific instructions related to your contract. Additionally, your company is responsible for keeping all authorized negotiators and agent delegations up-to-date in the system. For example, if you delegated pre-award responsibilities to a consultant or third-party agent and do not intend for these agents to represent your firm following contract award, you must specifically request that these agents be removed as authorized negotiators from your contract. Additional helpful information about processing modifications can be found through the eOffer/eMod Help Center.

    If you are a dealer/reseller of COTS products, and are adding a new manufacturer to your existing contract, you must submit a Letter of Supply, unless your manufacture participates in the Verified Products Portal (VPP); if they are VPP participants, you do not need to provide a Letter of Supply. GSA recommends checking the Verified Products Portal Participation Dashboard to determine if your products come from a manufacturer participating in the VPP. For more information about the Verified Products Portal, see attached "MAS Contractor - VPP Implementation Q&A"d [PDF - 123 KB]

Key Component: The following clauses are generally applicable to all Schedule contracts and should be clearly understood.

  • Review clause 52.222-26 Equal Opportunity:

    This clause requires that the Equal Opportunity Clause poster be displayed in a conspicuous place available to employees and applicants for employment. Subcontractors must similarly display the EEO poster. See the U.S. Equal Employment Opportunity Commission website for various versions of this poster. Contractors are also required to file the Equal Employment Opportunity EEO-1 Survey in accordance with the instructions found at U.S. Equal Employment Opportunity Commission Survey website.
  • Review clause 52.204-9 Personal Identity Verification of Contractor Personnel:

    This clause requires your company to comply with agency personal identity verification procedures identified in the contract that implement Homeland Security Presidential Directive-12 (HSPD-12), Office of Management and Budget (OMB) guidance M-05-24 and Federal Information Processing Standards Publication (FIPS PUB) Number 201.

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Last Reviewed: 2023-05-19