Section 3321 - Prompt payment to subconsultant design professional in contract for public works of improvement(a) In each contract for public works of improvement, a prime design professional shall pay to each subconsultant design professional the amount due him or her from the payment received, not later than 15 days after receipt of each progress payment or final retention payment. If the prime design professional disputes in good faith any portion of the amount due, he or she may withhold from the payment an amount not to exceed 150 percent of the disputed amount. The disputed amount withheld shall not be subject to any penalty authorized by this section.(b) If any amount is wrongfully withheld or is not timely paid in violation of this section, the subconsultant design professional shall be entitled to a penalty of 11/2 percent of the improperly withheld amount, in lieu of any interest otherwise due, per month, for each month that payment is not made. In any action for the collection of amounts withheld in violation of this section, the prevailing party shall be entitled to his or her reasonable attorney's fees and costs.(c) The penalty described in subdivision (b) shall be separate from, and in addition to, the design professionals liens provided by Chapter 3 (commencing with Section 8300) of Title 2 of Part 6 of Division 4, mechanics liens provided by Chapter 4 (commencing with Section 8400) of Title 2 of Part 6 of Division 4, and stop payment notices on public works provided by Chapter 4 (commencing with Section 9350) of Title 3 of Part 6 of Division 4.(d) None of the rights or obligations created by this section between prime design professionals and subconsultant design professionals shall apply to construction loan funds held by a lender pursuant to a construction loan agreement.(e) For purposes of this section: (1) "Public agency" means the state, any county, any city, any city and county, any district, any public authority, any public agency, any municipal corporation, or other political subdivision or political corporation of the state.(2) "Design professional" means a person licensed as an architect pursuant to Chapter 3 (commencing with Section 5500) of Division 3 of the Business and Professions Code, registered as a professional engineer pursuant to Chapter 7 (commencing with Section 6700) of Division 3 of the Business and Professions Code, or licensed as a land surveyor pursuant to Chapter 15 (commencing with Section 8700) of Division 3 of the Business and Professions Code.(3) "Prime design professional" means a design professional having a written contract directly with the public agency.(4) "Subconsultant design professional" means a design professional having a written contract with a prime design professional.Amended by Stats 2010 ch 697 (SB 189),s 19, eff. 1/1/2011, op. 7/1/2012.