48 CFR §19.502-4

1. (a)In accordance with section 1331 of the Small Business Jobs Act of 2010 (15 U.S.C. 644(r)(1)), contracting officers may, at their discretion, set aside a portion or portions of a multiple-award contract, except for construction, for any of the small business concerns identified at 19.000(a)(3) when—
   1. (1)Market research indicates that a total set-aside is not appropriate (see 19.502-2);
   2. (2)The requirement can be divided into distinct portions;
   3. (3)The acquisition is not subject to simplified acquisition procedures;
   4. (4)Two or more responsible small business concerns are reasonably expected to submit an offer on the set-aside portion or portions of the acquisition that are competitive in terms of fair market prices, quality, and delivery; and
   5. (5)The specific program eligibility requirements identified in this part apply.
2. (b)When the contracting officer determines that a requirement is to be partially set aside, the solicitation shall identify which portion or portions are set aside and not set aside.
3. (c)The contracting officer shall specify in the solicitation how offers shall be submitted with regard to the set-aside and non-set-aside portions.
4. (d)Offers received from concerns that do not qualify as small business concerns shall be considered nonresponsive and shall be rejected on the set-aside portion of partial set-asides. However, before rejecting an offer otherwise eligible for award because of questions concerning the size representation, an SBA determination must be obtained (see subpart 19.3).