Class Code: 6204

Per NCCI's Scopes Code Description:

Code 6204 is applied to specialist contractors engaged in drilling work provided such operations are not otherwise classified in the manual. This classification contemplates all types of drilling except drilling related to oil or gas wells or drilling in underground mines. The code is not applicable to the drilling of exploratory holes pursuant to oil or gas exploration.

Code 6204 applies to water well drilling; exploratory core drilling to determine the characteristics of ground strata, which will subsequently support a foundation of a structure; drilling of holes in rock for shot holes; drilling of holes for lag bolts to anchor sills of buildings; directional drilling; and drilling of holes in concrete or masonry walls, floors, etc., within buildings when performed by specialist drillers. The code is not applicable to nondrilling trades such as electricians, plumbers, etc. who will drill through wood or metal studs, etc. as part of performing their jobs.

Analogy Assignments:

The vibroflotation process for structuring building foundations is assigned by analogy to Code 6204 in view of certain similarities in this process and exploratory core drilling of soil by water jetting. In the latter process, chiseled shaped bits are attached to hollow drill rods and water is pumped through the rods and bits to wash the soil cuttings to the surface. Vibroflotation also involves the use of an underground jet stream of water to loosen and rearrange underground soil.

Equipment and Materials:

The equipment used by drilling specialists such as earth auger drills, jackhammers, drilling rigs and bits will vary depending upon the terrain or material to be drilled, the type of drilling and the depth and size of the holes to be drilled.

Additional Applications and Information:

Distinctions have been made between drilling operations (Code 6204) and excavation operations (Code 6217) as follows: Excavation generally contemplates the changing of the earth’s surface by a scooping out and/or shoveling aside process. Drilling generally contemplates the digging of a hole using a rotating or pounding-type tool.

Special Conditions:

Extra-Territorial Classification Guidelines:

The following material was developed by NCCI to be used as a guide by auditors and underwriters in the determination of premium for contracting (construction risks) with extra-territorial employments where no company guidelines have been established for this purpose. Construction classifications are indicated by the addition of a construction code symbol () next to the classification code number.

1.    Payroll of employees of contractors who have their place of business in a given state and operate also in adjoining states and who are constantly crossing state lines, but usually return to their homes each night, must be assigned to their headquarters’ state. Example: Contractors such as electricians, plumbers, carpet layers, etc.
2.    The payroll for construction project managers, executives, or superintendents who may visit a job but who are not in direct charge of a job must be assigned to the state in which their headquarters are located.
3.    There are contractors who maintain a permanent staff of employees and superintendents. If any of these employees or superintendents is assigned to a job that is located in a state other than their headquarters’ state, either for the duration of the job or any portion thereof, their payroll must be assigned to the highest rated of either the state in which the job is located or the headquarters’ state.
4.    The payroll of employees who is hired for a specific job project must be assigned to the state in which the job is located.

When a portion of the operations of a risk are insured in a monopolistic state fund, consider the special rules and requirements that may exist in such cases.

Related Operations Not Classified to Code 6204:

Certain Code 6204 operations are designated as “not otherwise classified” (NOC). The following is a representative list of operations somewhat related in nature to Code 6204 operations that are not assigned to Code 6204.

6325 Conduit Construction—For Cables and Wires
6217 Excavation
8606 Geophysical Exploration
6235 Oil or Gas Well—Drilling or Redrilling

In addition to this representative list, one should review sources such as the alphabetical index in this manual to determine whether a classification other than Code 6204 or a classification other than one on the above list is applicable to the operations being reviewed for classification purposes.


(N/A MA, TX)

Pump installation is to be separately classified from water well drilling provided that verifiable payroll records are maintained for each operation, and drilling equipment is not used to install the pump.

Rate per $100. of Renumeration: $ 5.63

Construction Exemption Required: Yes