Are Plumbing Companies Consolidating? What the Census Concentration Data Shows
The short answer
Slowly. The 50 largest plumbing, heating and air-conditioning firms earned 14.4 percent of the industry’s revenue in 2022, up from 12.6 percent in 2017, and the 4 largest 4.7 percent against 4.2, according to the Census Bureau’s Economic Census. Firms with $100 million or more in revenue went from 138 to 235, and their share of revenue from 18.9 to 25.6 percent. The four largest firms still hold under 5 percent of revenue.
The short answer, expanded
Private-equity buyers have spent the past decade assembling plumbing and HVAC platforms, and trade press coverage often suggests the independent shop is disappearing. The Economic Census measures what share of revenue the largest firms actually hold. It does not name them. Comparing 2017 and 2022 shows the direction and the size of the change.
| Concentration measure | 2017 | 2022 | Change (points) |
|---|---|---|---|
| Share of revenue, 4 largest firms | 4.2% | 4.7% | +0.5 |
| Share of revenue, 8 largest firms | 5.9% | 6.7% | +0.8 |
| Share of revenue, 20 largest firms | 8.6% | 10.2% | +1.6 |
| Share of revenue, 50 largest firms | 12.6% | 14.4% | +1.8 |
| Firms with $100M+ revenue | 138 | 235 | +97 firms |
| Their share of revenue (full-year firms) | 18.9% | 25.6% | +6.7 |
| Total firms | 101,561 | 112,088 | +10,527 |
Source: Census Bureau, Economic Census 2017 (EC1700SIZECONCEN, EC1700SIZEREVFIRM) and 2022 (ECNSIZE2022), NAICS 238220. Concentration shares are as published by the Census Bureau.
The evidence
- Revenue share of the 4 largest firms: 4.2 percent (2017), 4.7 percent (2022). Source: Census Bureau.
- 8 largest: 5.9 to 6.7 percent; 20 largest: 8.6 to 10.2; 50 largest: 12.6 to 14.4 percent. Source: Census Bureau.
- Revenue of the 50 largest firms: $26.0 billion to $42.9 billion. Source: Census Bureau.
- Firms with $100 million or more in revenue: 138 (2017), 235 (2022), with revenue of $38.2 billion and $73.9 billion. Source: Census Bureau.
- Total firms: 101,561 to 112,088. Source: Census Bureau.
- Herfindahl-Hirschman index for the 50 largest firms: 7.1 (2017) and 9.3 (2022), on a scale where 10,000 is a monopoly. Source: Census Bureau.
What the numbers imply
The biggest firms are growing faster than the industry
Formula. Revenue growth of the 50 largest firms against the whole industry, 2017 to 2022.
Calculation. Top 50: +65.0 percent. Industry: +44.3 percent.
Finding. The largest firms grew revenue about half again as fast as the industry. Some of that is acquisitions, which move revenue from small firms into big ones without creating any, and some is organic growth.
Limitations. The Census Bureau does not identify acquisitions, and the identity of the top 50 can change between censuses.
Yet there are more firms than ever
Formula. Change in the number of employer firms.
Calculation. 101,561 to 112,088, +10.4 percent; self-employed businesses also grew (see self-employed plumbers).
Finding. Consolidation at the top has not reduced the number of firms. New small shops are forming faster than acquired ones disappear, so the industry is concentrating at the top and growing at the bottom at the same time.
Limitations. Acquired firms that keep operating under their own name still count as part of the acquiring firm in the census.
Figures worth quoting
- The 50 largest plumbing/HVAC firms hold 14.4 percent of revenue (2022), up from 12.6 percent in 2017.
- The 4 largest hold 4.7 percent.
- 235 firms now earn $100 million or more a year, up from 138.
Download the data
Census concentration ratios, $100M+ firm counts and revenue, and totals. Published under a Creative Commons Attribution 4.0 licence. Attribution: The Plumbing Brief.
Plumbing/HVAC industry concentration, 2017 and 2022 (CSV)
How this report was built
Methodology
Source. US Census Bureau, 2022 Economic Census and 2017 Economic Census, files downloaded from www2.census.gov on 4 October 2026. Concentration ratios (share of revenue held by the 4, 8, 20 and 50 largest firms) and Herfindahl-Hirschman index for the 50 largest, as published in ECNSIZE2022 and EC1700SIZECONCEN; firm counts and revenue by revenue size from ECNSIZE2022 and EC1700SIZEREVFIRM; totals from the basic tables.
Derived figures. Shares, growth rates, per-firm and per-employee values are calculated by The Plumbing Brief from the published tables.
Retrieval date. 4 October 2026.
Data limitations
- The Economic Census counts employer establishments only. Businesses with no employees are covered by Nonemployer Statistics, reported separately.
- NAICS 238220 combines plumbing, heating and air-conditioning contractors. The kind-of-business split classifies each establishment by its primary activity; a plumbing-primary shop’s HVAC work is counted as plumbing-contractor revenue and vice versa.
- The Economic Census runs every five years. 2022 is the latest; 2027 results will follow around 2029.
- Revenue figures are nominal dollars. Inflation adjustments use the CPI-U annual average and are approximate for an industry whose input costs moved differently.
- Concentration is national; local market concentration, where acquisitions matter most for customers, can be much higher and is not published.
- Firms are not named; the report deliberately does not attempt to identify them.
Source quality ranking
Tier 1. US Census Bureau, 2022 Economic Census (construction sector files EC2223KOB, EC2223BASIC and the firm-size and product-line datasets ECNSIZE2022 and ECNNAPCSIND2022) and the 2017 Economic Census equivalents, downloaded from www2.census.gov.
Tier 2. None used. Tier 3. None used.
Excluded. Paid market-research estimates of plumbing industry size, which do not publish their method and differ widely from one another.
Briefing note
The 50 largest US plumbing, heating and air-conditioning firms earned 14.4 percent of the industry’s revenue in 2022, up from 12.6 percent in 2017, according to Census Bureau Economic Census concentration data analysed by The Plumbing Brief. The number of firms with $100 million or more in revenue rose from 138 to 235, while the total number of employer firms grew from 101,561 to 112,088. The industry remains highly fragmented.
How reporters could frame this
- Private equity’s plumbing roll-up, in Census numbers
- The top 50 plumbing and HVAC firms now hold one dollar in seven
- Consolidating at the top, multiplying at the bottom
- Is the independent plumber disappearing? Not yet
Related questions
Is the plumbing industry consolidating? Slowly. The 50 largest plumbing and HVAC firms held 14.4 percent of revenue in 2022, up from 12.6 percent in 2017 (Census Bureau).
How much of the market do the biggest plumbing companies control? The 4 largest firms held 4.7 percent of plumbing/HVAC contractor revenue in 2022.
How many plumbing companies make over $100 million? 235 plumbing/HVAC firms in 2022, up from 138 in 2017.
Are there fewer plumbing companies because of private equity? No. Employer firms rose from 101,561 to 112,088 between 2017 and 2022.
Does this show local market concentration? No. The Census figures are national.
How to cite this report
The Plumbing Brief, “Are Plumbing Companies Consolidating? What the Census Concentration Data Shows”, https://theplumbingbrief.com/are-plumbing-companies-consolidating/, accessed [date].
Last reviewed: 2026-10-04.
