Insurance Providers in United States

In US there are many companies who provide insurance but there are many providers who are limited in resource and they provide special type of insurance only. I have created list of companies who provide Healthcare Insurance. Also made category for specialized ones who provide only special type of Insurance. Links to reach these companies directly are embedded.

                                              Insurance Companies in the United States

21st Century Insurance
Aetna
Acuity
Aflac
Alleghany Corporation
Allied Insurance
Allstate
American Automobile Association
American Family Insurance
American Income Life Insurance Company
American International Group (AIG)
American National Insurance Company
Ameritas Life Insurance Company
Amica Mutual Insurance
Applied Underwriters
Arbella Insurance Group
Assurant
Auto-Owners Insurance
AXA Equitable Life Insurance Company
Bankers Life and Casualty Company
Berkshire Hathaway
California Casualty
Cincinnati Insurance Company
CNA Financial
Colonial Life & Accident Insurance Company
Combined Insurance
Commerce Insurance Group
Conseco
Country Financial
Chartis
Chubb Corp.
Elephant
Encompass Insurance Company
Erie Insurance Group
Esurance
Evergreen USA RRG
FM Global
Family Heritage
Farmers Insurance Group
Federated Mutual Insurance Company
First Catholic Slovak Ladies Association of the United States of America
FirstComp Insurance Company
First Insurance Company of Hawaii
GAINSCO
GEICO
General Re
Genworth Financial
GMAC Insurance
Gracy Title Company
Guarantee Insurance Company
Guardian Life Insurance Company of America
GuideOne Insurance
Hanover Insurance
The Hartford
HCC Insurance Holdings
Infinity Property & Casualty Corporation
IntelliQuote Insurance Services
Jackson National Life
John Hancock Insurance
K&K Insurance
Kansas City Life Insurance Company
Kentucky Farm Bureau
Liberty Mutual
Lincoln National Corporation
Markel Corporation
MassMutual Financial Group
Merchants Insurance Group
Mercury Insurance Group
MetLife
Mutual of Omaha
National Life
Nationwide Mutual Insurance Company
New Jersey Manufacturers Insurance Company
New York Life Insurance Company
Northwestern Mutual
Ohio Mutual Insurance Group
Omega
OneBeacon
Oxford Health Plans
Pacific Life
Pacificare
PEMCO
Penn Mutual
Philadelphia Contributionship for the Insurance of Houses from Loss by Fire
Philadelphia Insurance Companies
Principal Financial Group
Primerica
Progressive
Protective Life
Prudential Financial
QBE
The Regence Group
Reliance Insurance Company
RLI Corp.
Safe Auto Insurance Company
Safeco
Safeway Insurance Group
Secura Insurance Company
Sentry Insurance
Selective Insurance
Shelter Insurance
Southern Aid and Insurance Company
Standard Insurance Company
State Auto Insurance Group
State Farm Insurance
Sun Life Financial
Symetra
TIAA-CREF
The Main Street America Group
The Travelers Companies
Trupanion
Unitrin Direct Auto Insurance
Unum
USAA
West Bend
West Coast Life
Western Mutual Insurance Group
Western & Southern Financial Group
Westfield Insurance
White Mountains Insurance Group
Workmen's Auto Insurance Company
Zurich NA
Main article: Life annuity
Allstate
American Family Insurance
American Fidelity Assurance
Amica Mutual Insurance
AXA Equitable Life Insurance Company
Bankers Life and Casualty
Conseco
Farmers Insurance Group
Fidelity
Genworth Financial
ING Group
Jackson National Life
John Hancock Insurance
Lincoln National Corporation
MetLife
Mutual of Omaha
Nationwide Mutual Insurance Company
Old Mutual
Pacific Life
Protective Life
Prudential Financial
Standard Insurance Company
State Farm Insurance
Thrivent Financial for Lutherans
TIAA-CREF
Transamerica Corporation
UNIFI Companies
United of Omaha
Western & Southern Financial Group



                                              Major Medical Health insurance Providers 

AARP
Aetna
American Family Insurance
American National Insurance Company
Amerigroup
Anthem Blue Cross and Blue Shield
Assurant
Blue Cross and Blue Shield Association
Centene Corporation
Cigna
Coventry Health Care
EmblemHealth
Fortis
Golden Rule Insurance Company
Group Health Cooperative
GHI
Health Net
HealthMarkets
HealthSpring
Highmark
Humana
Independence Blue Cross
Kaiser Permanente
Kaleida Health
LifeWise Health Plan of Oregon
Medical Mutual of Ohio
Molina Healthcare
Premera Blue Cross
Principal Financial Group
The Regence Group
Shelter Insurance
State Farm
Thrivent Financial for Lutherans
UnitedHealth Group
Unitrin
Universal American Corporation
WellCare Health Plans
WellPoint


                                                               Medicare Providers

Aetna
American Family Insurance
Bankers Life and Casualty
Conseco
Kaiser Permanente
Mutual of Omaha
Premera Blue Cross
Thrivent Financial for Lutherans
Tricare

                                                      Supplemental Insurance Providers 

Aflac
Allstate
American Fidelity Assurance
Assurant
Colonial Life & Accident Insurance Company
Combined Insurance
Conseco
Liberty National Life Insurance Company
MEGA Life and Health Insurance
Mutual of Omaha
State Farm Insurance


                                                        Travel Insurance Providers

Seven Corners
Travel Guard
USA-ASSIST Worldwide Protection


                                                  Workers' Compensation Insurance Providers

Accident Fund
American International Group (AIG)
Cincinnati Financial Corporation
Erie Insurance Group
GUARD Insurance Group
Hanover Insurance
The Hartford
Liberty Mutual
Merchants Insurance Group
Missouri Employers Mutual
Nationwide Mutual Insurance Company
Penn National Insurance
Sentry Insurance
State Accident Insurance Fund
State Compensation Insurance Fund
State Farm Insurance
WellPoint
Zenith Insurance Company


Please leave names of Insurance Providers if i missed someone in Comments. So that they can be updated and people looking for list of healthcare providers will not have to waste time in search of providers.