SCH 13-G
UNITED
STATES
SECURITIES
AND EXCHANGE COMMISSION
Washington,
D.C. 20549
SCHEDULE
13G
Under
the
Securities Exchange Act of 1934
(Amendment
No. 20)*
Sierra
Health Services, Inc.
(Name
of
Issuer)
Common
Stock
(Title
of
Class of Securities)
826322-109
(CUSIP
Number)
December
31, 2006
(Date
of
Event Which Requires Filing of this Statement)
Check
the
appropriate box to designate the rule pursuant to which this Schedule is filed:
[
] Rule 13d-1(b)
[
] Rule 13d-1(c)
[x] Rule
13d-1(d)
*The
remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities,
and
for any subsequent amendment containing information which would alter
disclosures provided in a prior cover page.
The
information required on the remainder of this cover page shall not be deemed
to
be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934
("Act") or otherwise subject to the liabilities of that section of the Act
but
shall be subject to all other provisions of the Act (however, see the
Notes).
SCHEDULE
13G
CUSIP
No.
826322-109
1 NAME
OF REPORTING PERSONS (entities only)
I.R.S.
IDENTIFICATION NO. OF ABOVE PERSON
Anthony
M. Marlon, M.D.
---------------------------------------------------------------------------------
2 CHECK
THE APPROPRIATE BOX IF A MEMBER OF A GROUP (A)
|_|
(See
Instructions)
(B) |_|
---------------------------------------------------------------------------------
3 SEC
USE ONLY
---------------------------------------------------------------------------------
4 CITIZENSHIP
OR PLACE OF ORGANIZATION
United
States of America
5 SOLE VOTING
POWER
NUMBER
OF
4,372,080 shares of Common Stock at 12/31/06
SHARES
BENEFICIALLY
6 SHARED VOTING POWER
OWNED
BY
-0- at 12/31/06
EACH
REPORTING
7 SOLE DISPOSITIVE POWER
PERSON
4,372,080 shares of Common Stock at 12/31/06
WITH
8 SHARED DISPOSITIVE POWER
-0-
at 12/31/06
9 AGGREGATE
AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
4,372,080
shares of Common Stock at 12/31/06
---------------------------------------------------------------------------------
10 CHECK
BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES
CERTAIN
SHARES (See Instructions) |X| See Item 4 of attached Schedule 13G
---------------------------------------------------------------------------------
11 PERCENT
OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
8.2%
of outstanding class at 12/31/06
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12 TYPE
OF REPORTING PERSON (See Instructions)
IN
--------------------------------------------------------------------------------
Item
1.
(a) Name of Issuer:
Sierra
Health Services, Inc.
(b) Address of Issuer's Principal Executive
Offices:
2724
North Tenaya Way
Las
Vegas, Nevada 89128
Item
2.
(a) Name of Person Filing:
Anthony M. Marlon, M.D. ("Dr. Marlon")
(b) Address of Principal Business Office or, if none,
Residence:
2724 North Tenaya Way
Las
Vegas, Nevada 89128
(c) Citizenship:
United States of America
(d) Title of Class of Securities:
Common Stock, $.005 par value
(e) CUSIP Number:
826322-109
Item
3.
This statement is filed pursuant to Rule 13d-1(c). Items 3(a) through 3(h)
are,
therefore, inapplicable.
Item
4.
Ownership
(a) Amount Beneficially Owned:
Dr.
Marlon may be deemed to beneficially own 4,372,080 shares of Common Stock at
December 31, 2006. That number of shares reported as beneficially owned includes
3,826,954 shares held indirectly through a total of four trusts established
by
Dr. Marlon and his wife, 3,000 shares held indirectly through a limited
partnership (the "Partnership"), and 305,296 shares held indirectly by the
AMM&RM Family Limited Partnership ("ARFLP"). Dr. Marlon may be deemed
to have or share voting power and/or dispositive power over the shares held
by
the four trusts and, therefore, to have beneficial ownership with respect to
such shares. Dr. Marlon, as managing general partner of the Partnership, has
sole voting and dispositive power over the shares held by the Partnership.
Dr.
Marlon, as a general partner of ARFLP, may be deemed to have or share voting
and/or dispositive power over the shares held by ARFLP (a limited partnership
of
which Dr. Marlon, his spouse, and a trust for the benefit of Jeannine A. Zeller,
Dr. Marlon's daughter, are general and/or limited partners). Dr. Marlon
disclaims beneficial ownership as to the shares held by the four trusts, other
than the 1,439,630 shares held by the Marlon Family Trust (a revocable trust
of
which he is a trustee), and the shares held by ARFLP. The number of shares
reported as beneficially owned also includes 24,000 shares that Dr. Marlon
has a
right to acquire within 60 days of December 31, 2006, upon exercise of options,
and includes 212,830 shares held for Dr. Marlon's account under the Company's
401(k) plan for employees. Dr. Marlon's beneficial ownership does not include
560,020 shares held in five trusts for the benefit of family members, the
trustee of each of which is Erin E. MacDonald. Dr. Marlon's beneficial
ownership also does not include 168,000 shares deliverable in the future in
settlement of restricted stock units, which do not constitute beneficial
ownership because the options cannot be exercised and the restricted stock
units
cannot be settled currently or within 60 days after December 31,
2006.
(b)
Percent of Class:
8.2%
of
the class of Common Stock outstanding at December 31, 2006
(c)
Number of shares as to which Dr. Marlon has:
(i)
sole
power to vote or to direct the vote:
4,372,080 shares of Common Stock at December 31, 2006 (see Item 4(a) above)
(ii)
shared power to vote or to direct the vote:
-0-
shares of Common Stock at December 31, 2006
(iii)
sole power to dispose or to direct the disposition of:
4,372,080
shares of Common Stock at December 31, 2006 (see Item 4(a) above)
(iv)
shared power to dispose or to direct the disposition of:
-0-
shares of Common Stock at December 31, 2006
Item
5.
Ownership of Five Percent or Less of a Class
Not applicable.
Item
6.
Ownership of More than Five Percent on Behalf of Another Person
Not applicable.
Item
7.
Identification and Classification of the Subsidiary Which Acquired the Security
Being Reported on By the Parent
Holding
Company
Not applicable.
Item
8.
Identification and Classification of Members of the Group
Not applicable.
Item
9.
Notice of Dissolution of Group
Not applicable.
Item
10.
Certification.
Not applicable. This statement is filed pursuant to Rule 13d-1(d).
The filing of this Amendment to Schedule 13G and amendments hereto, and the
statements herein and therein, shall not be construed as an admission that
any
filing person or any other person named herein is, for purposes of Section
13(d), 13(g), 16(a), or 16(b) under the Exchange Act, or for any other purpose,
the beneficial owner of any of the securities described herein or therein,
except to the extent that a natural person is reported as having voting and
dispositive power, and thus beneficial ownership for purposes of Sections 13(d)
and 13(g), over securities owned directly by such person.
SIGNATURES
After
reasonable inquiry and to the best of my knowledge and belief, I certify that
the information set forth in this statement is true, complete and
correct.
February
12, 2007
Date
/s/
Anthony M. Marlon, M.D.
ANTHONY
M. MARLON, M.D.
Chairman
of the Board, Chief Executive Officer