Largest Insurance Companies in the U.S., by Line
Largest U.S. auto, home, life, and health insurance groups from their own NAIC market-share reports. No unsupported cross-line total.
The short answer
The largest insurer depends on the line of business: the NAIC reports separate auto, homeowners, individual-life, and accident-and-health markets. This page identifies each line's leader and links to its full source-backed ranking. It does not add their premiums into one overall list, because the report populations, group identifiers, and source vintages are not interchangeable.
How this comparison works
According to the National Association of Insurance Commissioners' market-share reports, this page reads the first five groups from four distinct NAIC line-of-business tables. All four tables currently cover calendar year 2024. Each figure remains attached to its original line, report year, and ranking methodology.
A group can appear under slightly different names or codes in different reports, and a premium total from one line is not evidence of a group-wide insurance total. The two charts below separate the largest reported group from the combined share of the top five; those ranks are not interchangeable.
Largest reported group, by line
Share of that line's NAIC market, not a cross-line size ranking
- Auto
State Farm Group
19 % share
- Home
State Farm Group
18 % share
- Life
Northwestern Mutual Group
9 % share
- Health
UnitedHealth Group
16 % share
What this shows Each bar is a different NAIC market. The auto leader's share is not evidence that the same group is largest in home, life, or health.
Top 5 combined share, by line
How much of each market the five largest reported groups hold together
- Auto
Five largest auto groups
64 % share
- Home
Five largest home groups
46 % share
- Life
Five largest life groups
29 % share
- Health
Five largest health groups
43 % share
What this shows A high combined share means the rest of the reported field is smaller. It is not a price, service, or denial ranking.
State Farm Group leads auto at 18.9% and home at 18.2% - nearly the same largest-group share - but the five largest auto groups hold 63.5% of that market while the five largest home groups hold 45.6%. Life is the other extreme: its largest group is 8.7% and its top five hold only 29.1%.
Largest reported groups in each market
| Insurance line | Largest reported group | Market share | Direct written premium | Data year |
|---|---|---|---|---|
| Auto | State Farm Group | 18.9% | $67.8B | 2024 |
| Home | State Farm Group | 18.2% | $31.5B | 2024 |
| Life | Northwestern Mutual Group | 8.7% | $13.7B | 2024 |
| Health | UnitedHealth Group | 16.1% | $269.4B | 2024 |
Where to go next
The table is a market map. The full rankings list the top records and their original NAIC metrics for each line.
- Auto insurance market-share ranking: top groups from the NAIC auto market-share report.
- Home insurance market-share ranking: top groups from the NAIC property/casualty market-share report.
- Life insurance market-share ranking: top groups from the NAIC individual-life market-share report.
- Health insurance market-share ranking: top groups from the NAIC accident-and-health market-share report.
What this analysis cannot tell you
Market share measures the scale of reported written premium. It does not measure claims service, financial strength, price, or coverage fit. It also cannot establish a single cross-line ranking until the group identities and report coverage are reconciled under a documented, reproducible method.
Frequently asked questions
Frequently Asked Questions
What is the largest insurance company in the US?
It depends on the line of business. State Farm Group leads auto insurance; State Farm Group leads home insurance; Northwestern Mutual Group leads life insurance; UnitedHealth Group leads health insurance (NAIC market-share reports, 2024). No single company leads every line, and NAIC does not publish a combined cross-line ranking.
Why doesn't this page combine the four lines into one ranking?
NAIC reports each line separately, with different group identifiers, reporting populations, and data years. Adding written premiums across lines would combine numbers that are not directly comparable, so this page keeps each line's leader in its own reported context.
What data year does this market-share data cover?
All four NAIC line tables on this page currently cover calendar year 2024. Each figure is tagged with its own report year.
How does NAIC calculate market share?
Market share is a group's direct written premium in a line divided by the total direct written premium reported for that line nationally, as published in NAIC's own market-share reports.
Source: National Association of Insurance Commissioners market-share reports. Each value remains attached to its original NAIC reporting line and data year.
Sources
- National Association of Insurance Commissioners, Market Share Reports. https://content.naic.org
- PlainInsurer data methodology
- All insurer profiles
- Complaint and denial-rate rankings