

What goes into determining the cost of a contract bond? Here is a basic introduction.
These are some of the most common contract bonds:
Some contract surety bond costs are related to a contractor’s qualifications, while others are based on the scope of work or the classification of construction work that is being completed. The contract price is also a factor.
These qualifying factors may affect the rate of the rate tier for a contractor:
Rates will vary based on the class of work, for which difficulty and risk are assessed:
Costs are also affected by such things as:
These basic factors are used in the calculation of premiums:
The following examples show premium calculations for common contract bond types. They do not cover all rating situations but are basic examples for insurance agents who are new to surety bonds. Contact your surety underwriter to get rate information for your account.
Related: "The ABCs of Surety Bonds: What’s the difference between surety bonds and insurance?"
Example 1: “Flat rate bond premium. This calculation is straightforward. The premium rate is a set dollar amount per $1,000 contract price. In this example, the premium is $30 per thousand, on a $1 million contract amount, or $30,000.
$1 million contract amount
100% performance and payment bonds
$1 million performance and payment bond penalties
Flat rate per thousand of $30/M
Total premium = $30,000
Percentage of the contract cost = 3% ($30,000/$1 million)
Example 2: Contract bond with a tiered or graduated rate. This example is based on the following factors:
Graduated rate tier calculation:
First $100M of contract price x $25/M = $2,500
Next $400M of contract price x $15/M = $6,000
Next $500M of contract price x $10/M = $5,000
Total premium = $13,500.
Percentage of the contract cost is 1.35% ($13,500/$1 million)
Example 3: Maintenance bonds. This example is based on a two-year 100% maintenance bond required upon project completion and acceptance, and 100% of contract and bond amounts. For the first year, there is no charge as it is included with the performance bond charge. Second-year is charged using a maintenance rate tier, as follows:
First $100M of contract price x $2.50/M = $250
Next $400M of contract price x $2.25/M = $900
Next $500M of contract price x $2.00/M = $1,000
Total premium = $2,150
Example 4: Overrun (AP) premium. This is based on a final status inquiry and/or final pay application showing change orders (CO), adding another $150,000 increase in the contract price.
Original Contract Price: $1 million
Revised Final Contract Price with COs: $1.15 million
COs of $150M contract price x $10/M = $1,500. AP
Note: The rate tier applied is the last rate tier of $10/M to these COs. An underrun (RP) premium would use a similar calculation by deducting the COs from the original contract price to figure the RP.
Consult your underwriter for the surety’s specific rate and premium approval before quoting rates or premiums to the contractor. Your underwriter is your partner and will be happy to help you understand the cost calculations and answer your questions.
If you have any questions about anything regarding surety, contact an appointed agent, or reach out to an Old Republic Surety branch nearest you.
Related: "Abbreviation for Million and Thousand: K & MM Meaning"
Todd Taylor is a Commercial Surety Underwriting Consultant with our Orlando Old Republic Surety branch office. He’s worked in the surety industry in the Midwest and Florida over 25 years. He has a bachelor's degree in business finance and CPCU, AFSB designations. He enjoys travel and photography.