UnitedHealth Group Completes Acquisition of Sierra Health Services

-- Companies Receive Approval from U.S. Department of Justice;
UnitedHealth Group Agrees to Divest Individual Medicare
Advantage Plans in Clark and Nye Counties, Nevada;

-- Combined Company Will Provide a Comprehensive Range of
Affordable Products and Services to Health Care Consumers in
the Southwest
MINNEAPOLIS & LAS VEGAS--(Business Wire)--
UnitedHealth Group (NYSE: UNH) and Sierra Health Services, Inc.
(NYSE: SIE) today announced that they completed their transaction
effective as of the close of business today. Under the merger
agreement, Sierra stockholders receive $43.50 in cash for each share
of Sierra common stock, representing an equity value of approximately
$2.6 billion.

The U.S. Department of Justice has provided approval of the
acquisition. As a condition of approval, UnitedHealth Group will
divest its individual SecureHorizons Medicare Advantage HMO plans in
Clark and Nye Counties, which represent approximately 25,000 members.
UnitedHealth Group has reached an agreement to transition these
members to Humana Inc., subject to customary closing conditions.

UnitedHealth Group and Humana have agreed to work together to
ensure a seamless transition of the individual SecureHorizons Medicare
Advantage HMO plans in Clark and Nye Counties and will notify affected
members as details become available. UnitedHealth Group emphasized
that post-divestiture, these members will continue to receive the
benefits they currently have, and there will be no interruption in
these members' health care coverage.

Group SecureHorizons Medicare Advantage plans offered to retirees
through commercial customers or contracts are currently excluded from
the divestiture and will continue to be operated by UnitedHealth
Group. Sierra will retain its Medicare Advantage HMO plans in Nevada
which are offered under the Senior Dimensions brand.

Ken Burdick, CEO of UnitedHealthcare, said, "We look forward to
building on our shared heritage of providing consumers access to
affordable, high-quality health care. Our goal is to offer Nevadans
the most comprehensive range of cost-effective, innovative health care
products and services in the Southwest."

Jonathon Bunker, president and COO of Sierra, said, "Joining our
two organizations will be good for Nevada's health care consumers,
good for the many dedicated professionals who provide their care and
good for the employees of Sierra. With greater resources and advanced
technology, we can now build upon our legacy by providing more options
for our members and expanded access to the largest national network of
hospitals, physicians and other care providers."

In connection with the transaction, UnitedHealth Group and Sierra
also reached an agreement with Nevada Attorney General Catherine
Cortez Masto that is consistent with the terms of the Department of
Justice consent decree. As part of that agreement, and consistent with
UnitedHealth Group's longstanding commitment of philanthropic
initiatives to improve and expand health care access for underserved
populations, UnitedHealth Group will make $15 million in charitable
contributions over the next five years to benefit health care
consumers and programs in the State of Nevada.

Today's news does not impact UnitedHealth Group's full year 2008
financial outlook, which previously included projected results for
Sierra. UnitedHealth Group continues to project full year revenue of
approximately $83 billion and earnings in the range of $3.95 - $4.00
per share.

About UnitedHealth Group

UnitedHealth Group is a diversified health and well-being company
dedicated to making health care work better. Headquartered in
Minneapolis, Minn., UnitedHealth Group offers a broad spectrum of
products and services through seven operating businesses:
UnitedHealthcare, Ovations, AmeriChoice, Uniprise, OptumHealth,
Ingenix, and Prescription Solutions. Through its family of businesses,
UnitedHealth Group serves approximately 70 million individuals
nationwide.

About Sierra Health Services, Inc.

Sierra Health Services, Inc., based in Las Vegas, is a diversified
healthcare services company that operates health maintenance
organizations, indemnity insurers, preferred provider organizations,
prescription drug plans and a multi-specialty medical group. Sierra's
subsidiaries serve over 860,000 people through health benefit plans
for employers, government programs and individuals. For more
information, visit Sierra's website at www.sierrahealth.com.

Forward-Looking Statements

This press release may contain statements, estimates, projections,
guidance or outlook that constitute "forward-looking" statements as
defined under U.S. federal securities laws. Generally the words
"believe," "expect," "intend," "estimate," "anticipate," "plan,"
"project," "will" and similar expressions, identify forward-looking
statements, which generally are not historical in nature. These
statements may contain information about financial prospects, economic
conditions, trends and uncertainties. We caution that actual results
could differ materially from those that management expects, depending
on the outcome of certain factors. These forward-looking statements
involve risks and uncertainties that may cause UnitedHealth Group's
actual results to differ materially from the results discussed in the
forward-looking statements. Some factors that could cause results to
differ materially from the forward-looking statements include: the
potential consequences of the findings announced on October 15, 2006
of the investigation by an Independent Committee of directors of our
historical stock option practices; the consequences of the restatement
of our previous financial statements, related governmental reviews,
including a formal investigation by the Securities and Exchange
Commission, and review by the Internal Revenue Service, U.S.
Congressional committees, U.S. Attorney for the Southern District of
New York and Minnesota Attorney General, a related review by the
Special Litigation Committee of the Company, and related shareholder
derivative actions, including whether court approval of the settlement
agreements between the Company and certain named defendants and the
dismissal of the derivative claims against all named defendants is
obtained, shareholder demands and purported securities and Employee
Retirement Income Security Act class actions, the resolution of
matters currently subject to an injunction issued by the United States
District Court for the District of Minnesota, a purported notice of
acceleration with respect to certain of the Company's debt securities
based upon an alleged event of default under the indenture governing
such securities, and recent management and director changes, and the
potential impact of each of these matters on our business, credit
ratings and debt; increases in health care costs that are higher than
we anticipated in establishing our premium rates, including increased
consumption of or costs of medical services; heightened competition as
a result of new entrants into our market, and consolidation of health
care companies and suppliers; events that may negatively affect our
contract with AARP; uncertainties regarding changes in Medicare,
including coordination of information systems and accuracy of certain
assumptions; funding risks with respect to revenues received from
Medicare and Medicaid programs; failure to achieve business growth
targets, including membership and enrollment; increases in costs and
other liabilities associated with increased litigation, legislative
activity and government regulation and review of our industry; our
ability to execute contracts on competitive terms with physicians,
hospitals and other service providers; regulatory and other risks
associated with the pharmacy benefits management industry; failure to
maintain effective and efficient information systems, which could
result in the loss of existing customers, difficulties in attracting
new customers, difficulties in determining medical costs estimates and
appropriate pricing, customer and physician and health care provider
disputes, regulatory violations, increases in operating costs, or
other adverse consequences; possible impairment of the value of our
intangible assets if future results do not adequately support goodwill
and intangible assets recorded for businesses that we acquire;
potential noncompliance by our business associates with patient
privacy data; misappropriation of our proprietary technology; failure
to complete or receive anticipated benefits of acquisitions; the
potential consequences of the New York Attorney General's
investigation into our provider reimbursement practices; and the
outcome of the divestiture of our individual SecureHorizons Medicare
Advantage HMO plans in Clark and Nye Counties (Nevada) and the
integration of the operations of the Company and Sierra Health
Services, Inc. after the divestiture.

This list of important factors is not intended to be exhaustive. A
further list and description of some of these risks and uncertainties
can be found in our reports filed with the Securities and Exchange
Commission from time to time, including annual reports on Form 10-K,
quarterly reports on Form 10-Q and current reports on Form 8-K. Any or
all forward-looking statements we make may turn out to be wrong. You
should not place undue reliance on forward-looking statements, which
speak only as of the date they are made. Except to the extent
otherwise required by federal securities laws, we do not undertake to
publicly update or revise any forward-looking statements.

UnitedHealth Group
John Penshorn, 952-936-7214
Senior Vice President
or
Brett Manderfeld, 952-936-7216
Vice President
or
Media:
UnitedHealthcare
Tyler Mason, 714-226-3530
or
Sierra Health Services
Peter O'Neill, 702-242-7156
Vice President
Public & Investor Relations

Copyright Business Wire 2008