Contract Clauses Regarding Bidding Subs
The following is taken from web resources and demonstrates the variability of contract language regarding subs. All the resources related to major educational institutions, but are designed by numbers because the below may not be the latest standard from the states or institutions and I don’t want my interpretation or cut and paste to be a commentary on any particular institution.
Summary
  For the five universities examined, 
Contract Language 
  University 1
From a recent RFP, the CM may select mechanical and electrical subs and pay them for preconstruction services, but
“selection and participation of subcontractors during preconstruction services phases does not guarantee or convey any rights to a contract for construction or construction services. The contract has a formal selection process for determine qualified subs.”
The [CM] will solicit and publicly conduct subcontractor bidding for all construction work except hat which is specifically exempted by the University.
The University wants to obtain the best value for funds expended. Competition is generally the preferred method of assuring the least cost and subcontracting by bid process is encouraged. Qualification-based selection or pre-qualification selection of specific subcontracts may be authorized by the University. The University understands that there may be times when the best interest of the project is served by the [CM] itself performing or otherwise exempting a portion of the work from the bidding process.”
Univesity 2. In [State], the matter may be determined by a statute
§ 51.782. CONTRACTS FOR  FACILITIES:  CONSTRUCTION  which says,” 
  MANAGER-AT-RISK.  (i)  A  construction manager-at-risk shall publicly advertise, in the manner prescribed  by the institution, and receive bids or proposals from trade contractors or  subcontractors for the performance of all major elements of the work other than  general conditions work.  The law does allow  the CM to self-perform some work, if the owner determines it is the best  value.  
  From a typical [State] contact: 
  5.7.1 In  accordance with Texas Education Code section  51.782, as amended, Construction Manager shall publicly advertise and solicit  competitive lump sum bids/proposals from trade contractors or subcontractors  for the performance of all major elements of the work other than the minor work  that may be included in General Conditions. Criteria for determining the bid/proposal  that provides the best value to the Owner shall be established by the Project  Team and included in the request for bids/proposals. The Construction Manager  shall notify the Owner in advance in writing of the date it will receive the  bids/proposals. 
University 3
  General Conditions
2.2.4.7  The [CM] shall: Assist the Owner and Design Professional in the preparation of  the necessary bidding information, bidding forms, and pre-qualification  criteria for bidders; develop subcontractor interest; establish bidding  schedules; advertise for bids; and conduct pre-bid conferences to familiarize  bidders with the bidding documents and management techniques and with any  special systems, materials, or methods.   The [CM] shall review all potential subcontractors with the Owner and  Design Professional and obtain Owner’s approval of the pre-qualification of any  subcontractor.  If the [CM] becomes aware  prior to any bid date that less than three (3) pre-qualified subcontractors  plan to bid any portion of any Bid Package or that anticipated bids from  previously approved or pre-qualified subcontractors are likely to exceed the  current Schedule of Values or estimate of Construction Cost, the [CM] shall  promptly notify the Owner. 
2.2.4.8 The [CM] shall receive and open bids when advertised, prepare a bid analysis, conduct pre-award conferences, and notify the Owner and Design Professional concerning which bids from pre-qualified subcontractors will be accepted and awarded. The Owner and Design Professional shall be notified of the time and place of all bid openings and shall be permitted to attend such openings with their representatives and guests. A proposal to accept other than a low lump sum bid shall be justified in writing by the [CM], and be subject to prior written approval by the Owner, with no increase in the GMP.
University 4
  [From an SOP manual]
2.12  Early Selection of Certain Subcontractors Owner has determined that it is advantageous to the Owner to  have the Subcontractors that will perform the Construction Work in the  following trades participate in the design process for the Project during the  Design Phase: [INSERT LIST OF MAJOR TRADES  THAT CAN MAKE A SIGNIFICANT CONTRIBUTION BY PARTICIPATING IN THE DESIGN PHASE.  THE LIST MUST BE TAILORED AND JUSTIFIED BY THE NEEDS OF THE PARTICUALR PROJECT.  FOR EXAMPLE: “mechanical, plumbing, electrical, fire sprinklers and glazing”]. Therefore, Subcontractors in these trades will be  selected at the beginning of the CMAR’s participation in the Design  Phase. This requires that the Subcontractor selection procedures in Section  2.11 apply in a modified form as set forth below to the selection of each  early selected Subcontractor (“Early Selected Subcontractor”). The Early Selected Subcontractors will be selected using the [a competitive  proposal system] 
University 5
    
    