Legal

Kentucky prompt payment act and retainage rules

Kentucky's Fairness in Construction Act (KRS 371.400 to 371.425) covers public and private nonresidential jobs: owners pay undisputed requests within 30 business days (45 for school boards and postsecondary schools), contractors pay subs within 15 business days, late money earns 12% a year, and retainage is capped at 10% until the job is half done, then 5%. KYTC highway contracts add their own biweekly pay and 7-day sub payment rules.

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Kentucky's main payment law for contractors is the Kentucky Fairness in Construction Act, KRS 371.400 to 371.425. It applies to public construction, public works, and private construction, but not residential work. The owner (the act calls it the contracting entity) must pay an undisputed, properly completed request within 30 business days, or 45 business days for a board of education or postsecondary institution. Contractors pay subs within 15 business days of being paid. Late payments and late retainage earn 12% a year, and retainage is capped at 10% until the project is 50% complete and 5% after. Kentucky Transportation Cabinet (KYTC) road and bridge contracts layer stricter spec terms on top: biweekly partial payments at 100% of the estimate and sub payment within 7 calendar days.

Kentucky payment and retainage rules at a glance
RuleFairness in Construction Act (public and private nonresidential)KYTC road and bridge work (2026 Standard Specifications)
Owner pays primeWithin 30 business days of a timely, properly completed, undisputed request; 45 business days for boards of education and postsecondary institutions (KRS 371.405)Partial payments biweekly on the engineer's estimate (109.05)
Interest on late payment12% per year, from the 31st business day (46th day for schools and postsecondary)12% statutory rate applies to public works under KRS 371.405
Notice before interestContractor sends certified mail notice at 25 business days if unpaid, with the date interest startsSame statute
Prime pays subsWithin 15 business days of receiving payment, including released retainage; 12% interest from the 16th business dayWithin 7 calendar days of receiving payment from the engineer (108.01)
Retainage cap10% of any undisputed payment until 50% complete; no more than 5% of the total contract after 51% (KRS 371.410)Each partial payment is 100% of the value due; no routine retainage listed in 109.05
Retainage releaseWithin 30 days after substantial completion, less 200% of the estimated cost of unfinished work; subs paid within 15 business daysFinal estimate within 180 days after final inspection and acceptance; 60 calendar days to agree or dispute (109.06)
Not coveredResidential construction; contracts by borrowers of USDA Rural Utilities Service funds; KRS Chapter 278 utility facilities (KRS 371.425)Not applicable

The Fairness in Construction Act: who it covers

KRS 371.425 says the act applies to public construction and public works projects and to private construction, excluding residential construction. It does not reach contracts by borrowers of funds provided, insured or guaranteed by the U.S. Department of Agriculture's Rural Utilities Service, or construction of utility facilities under KRS Chapter 278. The contracting entity can be a private owner, its trustee or agent, or a public official or public body authorized to contract. So a sub on a hospital addition, a county jail, or a distribution warehouse is covered. A custom home builder is not.

Payment deadlines and 12% interest

Under KRS 371.405, every covered construction contract must provide that amounts due the contractor, other than retainage, are paid within 30 business days after the contracting entity receives a timely, properly completed, undisputed request for payment. Boards of education and postsecondary institutions get 45 business days, and for school boards the Department of Education's 10-business-day approval step counts inside that window. Miss the deadline and interest runs at 12% per year on the unpaid amount. One step is easy to skip: at 25 business days, if payment has not arrived, the contractor must notify the contracting entity by certified mail and state the date interest begins. Calendar that notice the day you submit the pay app.

The flow-down runs on 15 business days. A contractor must pay its subs any undisputed amounts within 15 business days of receiving payment, including released retainage, as long as the sub sent a timely, properly completed, undisputed request. Interest at 12% starts on the 16th business day, and the same rule applies from each sub to its own subs. Say a GC collects $240,000 on a Lexington medical office job that includes $44,000 for the drywall sub. That $44,000 is due within 15 business days, roughly three calendar weeks. The act ties the deadline to the contractor's receipt of payment but does not expressly address pay-if-paid clauses, so read the subcontract.

Retainage: 10% to the halfway point, then 5%

KRS 371.410 overrides any other statute: until 50% of the project is complete, a contracting entity, contractor or sub may withhold no more than 10% from any undisputed payment, and retainage held after 51% completion may not exceed 5% of the total contract amount. Within 30 days after substantial completion, the retainage must be released, less 200% of the owner agent's reasonably estimated cost of any unfinished contract work. Contractors then have 15 business days to pass each sub its share. Late retainage earns 12% a year from the first business day after it was due.

Substantial completion has a strict meaning here. The contracting entity must certify it in writing, regulatory approvals must be in hand, the owner must have all warranties and documents, and the owner must be able to use the project for its intended purpose. Partial occupancy alone does not count, so push for the written certification.

KYTC road and bridge contracts

Section 109.05 of the KYTC Standard Specifications for Road and Bridge Construction, Edition of 2026, says the Department makes partial payments biweekly based on the engineer's estimate, paying 100 percent of the value due less previous payments. Under 109.05.01, stored materials are paid only once delivered to a site the Department owns or controls, which may mean granting it a no-charge temporary easement on a leased yard. Section 108.01 requires payment to subs within 7 calendar days from receipt of payment from the engineer, logged in AASHTOWare Project Civil Rights and Labor, and progress payments may be withheld for noncompliance. The prime must self-perform at least 30 percent of the total contract cost.

At closeout, 109.06 gives the engineer 180 days after final inspection and acceptance to compile the final estimate, and the contractor 60 calendar days to agree or file an item-by-item disagreement. Accepting payment for the final quantities acts as a release to the Commonwealth, so get disputes on paper first.

Other state and local bills

Two older statutes cover bills generally. KRS 45.453 and 45.454 require state purchasing agencies to pay within 30 working days of receiving goods, services or an invoice, with a 1% per month interest penalty after that. KRS 65.140 sets the same 30 working day rule and 1% monthly penalty for cities, counties and urban-county governments unless the contract says otherwise. Ask the agency which terms it applies to your contract. Keep Kentucky mechanics lien deadlines running while you chase money, and check Kentucky contractor license and Kentucky prevailing wage rules. Our prompt payment act primer covers the basics, and Smart Business Automator tracks pay apps, sub payments and retainage on every job; see construction accounts receivable automation.

Frequently asked questions

How long does a Kentucky owner have to pay a contractor?

Under KRS 371.405, 30 business days after receiving a timely, properly completed, undisputed request for payment. Boards of education and postsecondary institutions have 45 business days. Residential construction is not covered.

What interest applies to late construction payments in Kentucky?

Twelve percent per year under the Kentucky Fairness in Construction Act, for late owner payments, late sub payments, and late retainage.

What is the retainage limit in Kentucky?

Up to 10% of any undisputed payment until the project is 50% complete. After 51% completion, retainage held may not exceed 5% of the total contract amount (KRS 371.410).

How fast must a prime pay subs in Kentucky?

Within 15 business days of receiving payment under KRS 371.405. On KYTC highway contracts, the Standard Specifications require payment within 7 calendar days of receiving payment from the engineer.

Does KYTC hold retainage on road and bridge contracts?

Section 109.05 of the 2026 specs calls for paying 100 percent of the estimated value due on each biweekly partial payment. The final estimate can still show retained percentages and deductions.

Sources

  1. Kentucky Legislative Research Commission: KRS 371.400, definitions (Kentucky Fairness in Construction Act)
  2. Kentucky Legislative Research Commission: KRS 371.405, payment of amounts due
  3. Kentucky Legislative Research Commission: KRS 371.410, retainage
  4. Kentucky Legislative Research Commission: KRS 371.415, costs and attorney's fees
  5. Kentucky Legislative Research Commission: KRS 371.425, applicability
  6. Kentucky Legislative Research Commission: KRS 45.453, time period for payment
  7. Kentucky Legislative Research Commission: KRS 45.454, penalty for late payment
  8. Kentucky Legislative Research Commission: KRS 65.140, local government payment
  9. Kentucky Transportation Cabinet: Standard Specifications for Road and Bridge Construction, Edition of 2026

Laws and rates change. Confirm current requirements with the state agency before you bid, file, or pay. This page is general information, not legal advice.

Written and edited by

Maurice Francois writes and edits construction operations guides for Smart Business Automator. More from Maurice on the Scaling Legends podcast.

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