Elementary and Secondary Education Act of 1965, as amended, Title VII, Part A, Subpart 3, Sec. 7131(a)(4); 20 U.S.C 7451(a)(4).

There are no program regulations for the STEP program. However, general administrative provisions that apply to all Education Department grants may be found here (note that Part 80 contains the grant requirements for Indian tribal governments): EDGAR; 34 CFR parts 75, 77, 79, 80, 81, 82, 84, 85, 86, 97,98 and 99.
Note: The regulations in 34 CRF part 79 apply to all applicants except federally recognized Indian tribes.

For guidance on allowable costs under Federal grants, see OMB Circular A-87, Appendices A and B, at 2 CFR Part 225, available here:
http://www.gpo.gov/fdsys/pkg/CFR-2012-title2-vol1/pdf/CFR-2012-title2-vol1-part225-appA.pdf

For State-recognized tribes that are nonprofit organizations, the cost principles are in Circular A-122, Appendices A and B, at 2 CFR Part 230, available here:

www.gpo.gov/fdsys/pkg/CFR-2012-title2-vol1/pdf/CFR-2012-title2-vol1-part230-appA.pdf

http://www.gpo.gov/fdsys/pkg/CFR-2012-title2-vol1/pdf/CFR-2012-title2-vol1-part225-appB.pdf

For more information visit the Federal Register Notice located at this link: Federal Register Notice.