How many are licensed in Delaware, what level they hold, and how that compares per resident.
As of October 6, 2026, Delaware has 938 licensed plumbers on its state register, 938 of them at master level.
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“How many plumbers” has more than one honest answer, and published figures disagree because they count different things without saying so. Here is each measure ATI holds for Delaware, named.
| Measure | Count | What it counts |
|---|---|---|
| Licensed workers on the state register | 938 | Records the register does not mark expired, revoked or surrendered, and that it evidences as a license actually held. This is the figure every ATI surface reports as `current`, and the figure this page leads with. |
| ...of those, explicitly marked active | 451 | The narrower subset a register flags as active. Smaller, because many states publish no status at all and those records are counted above but not here. |
| All license records, active or not | 941 | Includes lapsed, expired and inactive records. Larger, and not a workforce count. |
| Industry employment (BLS QCEW) | 3,358 | Everyone on the payroll of establishments in this industry, including office and sales staff, and counting a person once per job rather than once per license. |
| Estimated workers in this occupation (ATI model) | 1,414 | Not a published figure: county construction employment scaled by this occupation's share of the metro workforce. An estimate, shown as one. |
| Employer establishments | 335 | Physical business locations, not people. BLS QCEW where the county is disclosed, otherwise an ATI estimate on the same occupation share. |
| Registered apprentices | 188 | In a registered program, working toward a license but not yet holding one. |
ATI's headline figure is the first row: individual people holding an active license, counted from the state register itself and refreshed nightly. See methodology and sources.
| State | Licensed plumbers | Per 100k |
|---|---|---|
| District of Columbia | 1,287 | 189.6 |
| Nevada | 986 | — |
| Delaware | 938 | 90.9 |
Delaware is part of 415,580 licensed plumbers nationally, and ranks #28 of 32 published states by per-capita density.
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