The Louisiana Public Bid Law, Louisiana Revised Statutes, Title 38, Chapter 10, applies to public works and to purchases of materials, supplies and vehicles.
Public Works:

The Tangipahoa Parish School System shall advertise and receive bids through the formal sealed bidding process, for all public works exceeding $100,000. The advertisement for any contract for public works, when published, shall appear once a week for three weeks in the official journal and the first advertisement shall appear at least twenty-five days before the opening of the bids.
Materials, Supplies and Vehicles:

The Tangipahoa Parish School System shall advertise and receive bids through the formal sealed bidding process for purchases of materials or supplies exceeding the sum of $20,000. Any advertisement for the purchase of materials or supplies shall be published two times in the official journal, the first advertisement appearing at least fifteen days prior to the opening of bids.

Purchases of materials or supplies of at least $10,000, but not more than $20,000, shall be made by obtaining at least three written or fax quotes. If a vendor is selected because of reasons other than the lowest price, those reasons will be fully documented and a notation shall be entered into the file as to the reasons for rejection of the lower quotes.

The public bid law does not apply to the following:

• Leases of movable property
• Professional services
• Insurance contracts
• Leases or purchases of real estate
• Purchases off of state contract