Engaging the district/center small business office is a great option to locate potential small business subcontractors.  While the district/center can not recommend one firm over another, they can provide you information on any small business that has indicated interest on specific projects, small businesses that currently do work for the district/center under specific NAICS and can provide other recommendations to assist your good faith efforts.

FAR 5.206 allows contractors awarded a contract that is likely to result in the award of subcontracts to utilize the Government Point of Entry (SAM.gov) to post notices seeking competition for subcontracts in order to assist in meeting subcontracting goals and providing maximum competition.   Seek assistance from the prime contract contracting officer if you have questions on this.

The Department of Defense subcontracting website includes a variety of resources for large businesses, including guides for your subcontract reporting.

This page also has resources to help you understand the different between subcontracting plans and small business participation evaluation factors- this is a confusing topic for many contractors large and small and this resource will help you understand the difference in case you are submitting a proposal that requires both.  

https://business.defense.gov/Acquisition/Subcontracting/Small-Business-Professionals-Government-and-Industry/ 

If you hold a Federal contract that includes FAR 52.219-9 and you have an acceptable subcontracting plan incorporated into your contract, ensure that your company understands all responsibilities required by the clause, especially outside of just reporting requirements.  As an Other than Small Business, you are also committing to educating small businesses on doing business with your firm, and ensuring maximum practicable inclusion of small businesses on your prime contract.  

Review the Interested Vendors list on open solicitations for potential small businesses.

Information included in a contractor's SAM profile feeds to DSBS, however small businesses have an opportunity to include additional information to assist you in determining potential small business subcontractors, at least for initial outreach.  The site can include capabilities narratives, keywords for searching, bonding limits, and references.  You have the capability to export searches to excel files for easy record keeping and to use as source lists.  DSBS Link

SBA's Subnet is another option to advertise specific subcontracting opportunities for small businesses.  This site allows you to include NAICS, place of performance and other fields to search for appropriate small businesses.   Subnet

The list of contracts with Small Business Subcontracting Plans is based on reported information in the Electronic Subcontracting Reporting System (eSRS).  Contracts awarded to Other than Small Businesses with a total contract value over $750K or $1.5M for construction requires a subcontracting plan, and contractors report their actual subcontracting achievements for the contract bi-annually. 

As a small business, you can use this list as a starting point to reach out to the appropriate companies (based upon the contract Product/Service Code) to inquiry about potential subcontracting opportunities for the current or future contracts. 

You can also use this list as a potential conversation starter with the appropriate district Small Business Professional to discuss recommendations for projects that may have further subcontracting opportunities.  Contracts with Subcontracting Plans

As a small business performing on a Federal contract with a value greater than $250K, you will also have responsibilities related to subcontracting.  It is important to understand these expectations.  

FAR 52.219-8 Utilization of Small Business Concerns-  This is applicable to both small and other than small businesses.

• You will provide small business concerns a maximum opportunity to participate in any subcontracting opportunities
• You agree to participate in studies or surveys to determine the extent you have done this
• You have processes in place to ensure maximum opportunity and timely payment to small business subcontractors

FAR 52.219-14 Limitations on Subcontracting- This is applicable on any small business or socio-economic set aside over $250K.

• You comply with the self-performance requirements for performance of the contract (note: credit for similarly situated entities)
• Subcontracts with "Other than Small Businesses" could be scrutinized, depending on dollar value and complexity/value of subcontract
• Compliance is monitored by the contracting officer

Compliance with both of these clause requirements could impact your Contractor Performance and Assessment Reporting System (CPARS) rating.

Department of Defense Office of Small Business website includes miscellaneous resources related to Subcontracting for Small Businesses, including the DoD Prime Contractor Directory.  This site includes basic guides to subcontracting in general that may be helpful to your business in understanding all of the Federal Government subcontracting rules and regulations and how to navigate them as a small business.

SBA provides valuable information for potential small business subcontractors at https://www.sba.gov/federal-contracting/contracting-guide/prime-subcontracting

Use information available at SAM.gov to locate award notices, list your company as an interested vendor on specific procurements or view other interested vendors as a networking tool for potential partnerships , and/or respond to sources sought notices as a potential subcontractor.  Use our handy "How-To" guide for specific information on how to use this resource to identify subcontracting opportunities.

USASpending  is a valuable tool to help you research and navigate information on Federal contract awards and subcontracts.  Using the Advanced Search function under "Award Search" you can toggle and search for Sub-Awards.  This site actually captures data on any Federal contract that had a reported sub-award (subcontract) valued over $30K, regardless of whether the contract had a formal small business subcontracting plan or not.  This is great business intelligence for small businesses to identify prime contractors and types of work that may have additional opportunities.

Utilize SBA Subnet to identify subcontracting opportunities by place of performance or use the Advanced Search capability to search by keywords, NAICS and other filters.  This site is primarily used by contractors to search directly for other contractors, however it is also a tool to advertise various outreach events.

Attend relevant site visits and/or project specific industry days to network with potential prime contractors.  Review the list of site visit attendees if you are unable to attend and reach out to potential partners as applicable.