How to sell to Missouri counties

Missouri has 114 counties plus the independent City of St. Louis. RSMo 50.660 sets the basic county bidding rule, and the same $12,000 rule covers goods, services and construction. Other statutes add rules for bonds (107.170), prevailing wage (290.230), retainage and prompt payment (8.960), and certifications. Charter counties such as St. Louis and Jackson may have their own purchasing codes; check the county's code.

At a glance

Topic	Rule	Source
Who buys	County Commission; department heads sign in the county's name; optional purchasing agent	RSMo 50.660; 50.753
Goods and services	Advertise at $12,000 or more; no bids at $12,000 or less per vendor per 90 days	RSMo 50.660
Construction	Same $12,000 rule as purchases	RSMo 50.660
Notice	Local newspaper with 500+ circulation, if one exists; no minimum days	RSMo 50.660
Award	Lowest and best bidder; all bids may be rejected	RSMo 50.660
Bid security	Not confirmed; check the solicitation	—
Bonds	Contractor bond on public works over $50,000; amount set by county	RSMo 107.170
Prevailing wage	Public works over $75,000	RSMo 290.230
Retainage	Max 5% (10% if no bond required); 98% due within 30 days of completion	RSMo 8.960
Prompt payment	Public works: 30 days; 1.5% per month late interest	RSMo 8.960
Cooperative purchasing	State Cooperative Procurement Program open to approved political subdivisions	RSMo 34.046; OA
Preferences and certifications	Reciprocal preference, Buy American, E-Verify over $5,000, Israel boycott at $100,000+	RSMo 34.076; 34.353; 285.530; 34.600
Architects and engineers	Qualifications-based evaluation by political subdivisions	RSMo 8.289

Who buys

Most counties are governed by an elected County Commission (a presiding commissioner and two associate commissioners). Contracts are executed in the county's name, or the township's name in township-form counties, by the responsible department head or officer. Purchasing officers may handle certain supply and equipment contracts (RSMo 50.660). Any county commission may appoint a county purchasing agent by order (RSMo 50.753).

Goods and services

Purchase	Rule
$12,000 or less from one vendor within any 90 days	No bids required
$12,000 or more	Advertise and let to the lowest and best bidder after due opportunity for competition

Source: RSMo 50.660. The $12,000 figure was set by 2021 H.B. 271 and is not indexed for inflation. State law has no middle quote tier; counties set their own quote rules. Some older guides still show a $6,000 figure (secondary: MU Extension township guide); that is outdated.

Single feasible source. The commission may waive bidding by a written finding entered in its minutes. If the purchase is over $12,000, it must publish notice in at least one daily and one weekly newspaper at least 10 days before letting the contract (RSMo 50.783). See sole source.

Construction and public works

RSMo 50.660 covers "all contracts and purchases," so county construction follows the same $12,000 advertising rule. Within the prevailing wage chapter, public bodies are exempt from competitive bidding requirements for projects with an estimate or accepted bid of $10,000 or less (RSMo 290.230). We did not find a separate statewide county road and bridge bid threshold.

Bid security. We found no statewide county bid bond statute. Check the solicitation.

Bonds. Public entities, including counties, must require a contractor bond with good and sufficient sureties on public works contracts estimated over $50,000. The bond guarantees payment for materials, insurance premiums and labor, including subcontractors and suppliers. The county sets the amount; the statute sets no percentage. Suppliers without a direct contract with the prime contractor must give written notice of nonpayment within 90 days of last supplying materials (RSMo 107.170).

Retainage. Retainage on public works is capped at 5%, or up to 10% where no bond is required (contracts not over $50,000). At least 98% of retainage is due within 30 days after substantial completion and acceptance. The owner may hold back 150% of the value of minor unfinished items (RSMo 8.960).

Notice and award

Advertise in a newspaper in the county with a circulation of at least 500 copies per issue, "if there is one." The statute sets no number of days or insertions (RSMo 50.660). Many counties use about two weeks by policy, but that is not a state rule. Award goes to the "lowest and best bidder after due opportunity for competition," and the county may reject all bids and advertise again (RSMo 50.660). We did not find a general statutory RFP process for counties.

Prevailing wage

Prevailing wages apply to public works built by or for any public body, excluding maintenance work (RSMo 290.230).
They don't apply when the engineer's estimate or accepted bid is $75,000 or less, measured on the whole project. Projects may not be split to get under that amount (RSMo 290.230).
The Department of Labor issues an Annual Wage Order by July 1 (Missouri Department of Labor).
Before advertising, the public body requests wage rates from the state and puts them in the bid specifications (RSMo 290.250).

See prevailing wage.

Getting paid

On public works, counties are "public owners" under RSMo 8.960. They must pay within 30 days, and late payments earn interest of 1.5% per month. Design professionals must be paid within 30 days of a proper invoice. Retainage release follows the 30-day rule above (RSMo 8.960). We did not confirm a statewide prompt payment rule for county goods and services; check the contract.

Cooperative purchasing and state contracts

The Commissioner of Administration may join or sponsor cooperative agreements and let political subdivisions take part (RSMo 34.046). Eligible local governments may join the State Cooperative Procurement Program once approved (Office of Administration). The program FAQ says state contracts satisfy Chapter 34 bidding and tells entities to confirm locally with counsel. It does not say a county's RSMo 50.660 duty is met. See cooperative purchasing.

Preferences and required certifications

Reciprocal preference. Applies to political subdivisions on public works and product bids, except purchases under $5,000 (RSMo 34.076).
Buy American. Political subdivision contracts for manufactured goods and public works must require US-made goods. Exceptions include purchases under $25,000, cost increases over 10%, or a written county policy encouraging US-made purchases (RSMo 34.353).
E-Verify. Contracts or grants over $5,000 require a sworn affidavit that the vendor is enrolled in a federal work authorization program and does not knowingly employ unauthorized aliens (RSMo 285.530).
Israel boycott. Companies with 10 or more employees must certify they will not boycott Israel on contracts worth $100,000 or more (RSMo 34.600).

Local or veteran preferences, Iran divestment and non-collusion affidavits were not confirmed statewide; check the solicitation.

Architects and engineers

State agencies and political subdivisions evaluate architecture, engineering and land surveying firms on qualifications such as experience, capacity, past performance and proximity (RSMo 8.289). This is qualifications-based selection. Fee negotiation steps were not confirmed.

Recent changes

Aug. 28, 2025: Current version of the public works bond statute took effect (2025 H.B. 199; RSMo 107.170).
Aug. 28, 2026: E-Verify affidavit statute amended (2026 H.B. 2366 and 2511; RSMo 285.530). Check current forms.
Aug. 28, 2026: Cooperative purchasing statute amended to cover cooperative contracts from nonprofit organizations with governmental members (2026 H.B. 2474; RSMo 34.046).

Practical tips for Missouri

Watch local newspapers and county websites; purchases of $12,000 or more are advertised, and notice periods can be short.
Ask small-purchase buyers about vendor lists; buys of $12,000 or less need no bids.
Have your E-Verify affidavit ready for any contract over $5,000 (RSMo 285.530).
Watch County Commission agendas, which often include bid openings, sole source findings and awards.
Check Missouri counties for each county's bid platform, contacts and agendas.

Questions

What is the bid threshold for Missouri counties?

Contracts and purchases of $12,000 or more must be advertised and let to the lowest and best bidder. Purchases of $12,000 or less from one vendor within any 90-day period need no bids (RSMo 50.660).

How do Missouri counties advertise bids?

In a newspaper in the county with a circulation of at least 500 copies per issue, if there is one. The statute sets no minimum number of days (RSMo 50.660).

What bond do Missouri counties require on public works?

For public works contracts estimated over $50,000, the contractor must furnish a bond with good and sufficient sureties, in an amount the county sets. It guarantees payment for materials, insurance and labor (RSMo 107.170).

Does Missouri prevailing wage apply to county projects?

Yes, to public works construction by public bodies when the engineer's estimate or accepted bid is over $75,000. Maintenance work is excluded and projects may not be split to avoid it (RSMo 290.230).

How much retainage can a Missouri county hold?

Up to 5% on public works, or up to 10% where no bond is required. At least 98% of retainage is due within 30 days after substantial completion and acceptance (RSMo 8.960).

Do Missouri county contracts require E-Verify?

Yes. Contracts over $5,000 with any political subdivision require a sworn affidavit of enrollment in a federal work authorization program (RSMo 285.530).

Can a Missouri county skip bidding for a single source?

Yes. The commission may waive bidding by a written finding in its minutes. If the purchase is over $12,000, it must give notice in a daily and a weekly newspaper at least 10 days before letting the contract (RSMo 50.783).

Sources

Last reviewed Oct 31, 2026. This is general information, not legal advice. Laws and thresholds change; check the current statute and the bid documents.