<Page>
________________________________________________________________________________
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
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SCHEDULE TO/A
(RULE 14d-100)
TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR SECTION 13(e)(1)
OF THE SECURITIES EXCHANGE ACT OF 1934
AMENDMENT NO. 39
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NCS HEALTHCARE, INC.
(Name of Subject Company (Issuer))
OMNICARE, INC.
NCS ACQUISITION CORP.
(Names of Filing Persons (Offerors))
CLASS A COMMON STOCK, PAR VALUE $0.01 PER SHARE
(Title of Class of Securities)
62887410
(CUSIP Number of Class A Common Stock)
AND
CLASS B COMMON STOCK, PAR VALUE $0.01 PER SHARE
(Title of Class of Securities)
NOT APPLICABLE
(CUSIP Number of Class B Common Stock)
CHERYL D. HODGES
SENIOR VICE PRESIDENT AND SECRETARY
OMNICARE, INC.
100 EAST RIVERCENTER BOULEVARD
COVINGTON, KENTUCKY 41011
TELEPHONE: (859) 392-3300
(Name, Address and Telephone Number of Person Authorized to Receive
Notices and Communications on Behalf of Filing Persons)
COPY TO:
MORTON A. PIERCE, ESQ.
DEWEY BALLANTINE LLP
1301 AVENUE OF THE AMERICAS
NEW YORK, NEW YORK 10019
TELEPHONE: (212) 259-8000
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CALCULATION OF FILING FEE
<Table>
Transaction Valuation* Amount of Filing Fee
$144,283,651 $13,274.10
</Table>
* Estimated for purposes of calculating the amount of the filing fee only. This
amount assumes the purchase of (i) 18,523,502 shares of the class A common
stock, par value $0.01, of NCS Healthcare, Inc., a Delaware corporation (the
'Company'), representing all of the issued and outstanding shares of such class
as of July 28, 2002 (less 1,000 shares of such class owned by Omnicare, Inc.),
(ii) 5,193,307 shares of the class B common stock, par value $0.01, of the
Company, representing all of the issued and outstanding shares of such class as
of July 28, 2002, (iii) 2,422,724 shares reserved for issuance upon the
exercise of outstanding options to purchase class A common stock and (iv)
94,858 shares reserved for issuance upon the exercise of outstanding options
to purchase class B common stock.
[x] Check box if any part of the fee is offset as provided by Rule 0-11(a)(2)
and identify the filing with which the offsetting fee was previously paid.
Identify the previous filing by registration statement number, or the Form
or Schedule and the date of its filing.
<Table>
Amount Previously Paid: $18,363.37 Filing party: Omnicare, Inc.
Form or Registration No.: SC TO Date Filed: August 8, 2002
</Table>
[ ] Check the box if the filing relates solely to preliminary communications
made before the commencement of a tender offer.
Check the appropriate boxes below to designate any transactions to which the
statement relates:
[x] third-party tender offer subject to Rule 14d-1
[ ] issuer tender offer subject to Rule 13e-4
[ ] going private transaction subject to Rule 13e-3
[ ] amendment to Schedule 13D under Rule 13d-2
Check the following box if the filing is a final amendment reporting the results
of the tender offer [ ]
________________________________________________________________________________
<Page>
This Amendment No. 39 amends and supplements the Tender Offer Statement on
Schedule TO filed with the Securities and Exchange Commission (the "Commission")
on August 8, 2002 (the "Schedule TO") by Omnicare, Inc., a Delaware corporation
("Omnicare"), and NCS Acquisition Corp., a Delaware corporation ("Purchaser")
and a wholly-owned subsidiary of Omnicare. The Schedule TO relates to a tender
offer by Purchaser to purchase all of the issued and outstanding shares of
class A common stock, par value $0.01 per share, and class B common stock, par
value $0.01 per share, of NCS HealthCare, Inc., a Delaware corporation (the
"Company"), at a price of $5.50 per share, net to the seller in cash, without
interest and less required withholding taxes, upon the terms and subject to the
conditions set forth in the Offer to Purchase, dated August 8, 2002 (the "Offer
to Purchase"), as amended and supplemented by the Supplement to the Offer to
Purchase, dated December 23, 2002 (the "Supplement"), and in the related revised
Letter of Transmittal (the "Letter of Transmittal" which, together with the
Offer to Purchase and the Supplement, as hereby or hereafter amended or
supplemented from time to time, constitute the "Offer"). Copies of the Offer to
Purchase, the Supplement and the related revised Letter of Transmittal are
attached as Exhibits (a)(1)(A), (a)(1)(HHH) and (a)(1)(III), respectively, to
the Schedule TO. Capitalized terms used and not defined herein shall have the
meanings assigned such terms in the Offer to Purchase, the Supplement and the
Schedule TO.
Item 11. Additional Information.
The discussion set forth under Section 18 ("Legal Proceedings") of the
Offer to Purchase and Section 11 ("Legal Proceedings") of the Supplement is
hereby amended and supplemented as follows:
The NCS HealthCare stockholder-plaintiffs' Motion for Temporary
Restraining Order will be heard by the Court of Chancery of the State of
Delaware (the "Chancery Court") on Thursday, January 2, 2003 at 2:00 p.m. The
stockholder-plaintiffs are seeking an order (i) temporarily, preliminarily and
permanently enjoining Omnicare and the Purchaser from distributing $13,500,000
of the amount otherwise payable to stockholders of the Company in the Offer and
(ii) requiring that Omnicare and the Purchaser deposit this sum in escrow until
the Chancery Court determines the rights of the stockholder-plaintiffs and their
counsel to an allowance of fees and expenses in connection with the
stockholder-plaintiffs' action against the Company and its directors entitled
"In re NCS HealthCare Shareholders Litigation" (C.A. No. 19786).
<Page>
SIGNATURE
After due 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.
Dated: December 30, 2002
OMNICARE, INC.
By: /s/ DAVID W. FROESEL, JR.
-------------------------------
Name: David W. Froesel, Jr.
Title: Senior Vice President
and Chief Financial Officer
NCS ACQUISITION CORP.
By: /s/ DAVID W. FROESEL, JR.
-------------------------------
Name: David W. Froesel, Jr.
Title: Vice President and Chief
Financial Officer
<Page>
EXHIBIT INDEX
<Table>
(a)(1)(A) Offer to Purchase dated August 8, 2002.*
(a)(1)(B) Letter of Transmittal.*
(a)(1)(C) Notice of Guaranteed Delivery.*
(a)(1)(D) Letter to Brokers, Dealers, Commercial Banks, Trust Companies and Other
Nominees.*
(a)(1)(E) Letter to Clients for use by Brokers, Dealers, Commercial Banks, Trust
Companies and Other Nominees.*
(a)(1)(F) Guidelines for Certification of Taxpayer Identification Number on
Substitute Form W-9.*
(a)(1)(G) Summary Advertisement, published August 8, 2002.*
(a)(1)(H) Press Release issued by Omnicare, Inc. on August 8, 2002.*
(a)(1)(I) Complaint filed in the Chancery Court, New Castle County, Delaware on
August 1, 2002.*
(a)(1)(J) Press Release issued by Omnicare, Inc. on August 8, 2002.*
(a)(1)(K) First Amended Complaint filed in the Chancery Court, New Castle County,
Delaware on August 12, 2002.*
(a)(1)(L) Press Release issued by Omnicare, Inc. on August 20, 2002.*
(a)(1)(M) First Amended Complaint filed in the United States District Court for the
Northern District of Ohio on August 21, 2002.*
(a)(1)(N) Press Release issued by Omnicare, Inc. on August 26, 2002.*
(a)(1)(O) Press Release issued by Omnicare, Inc. on September 6, 2002.*
(a)(1)(P) Selected material from a presentation of Omnicare, Inc. at the Bear Stearns
15th Annual Healthcare Conference on September 17, 2002 at The Waldorf
Astoria, New York, New York.*
(a)(1)(Q) Press Release issued by Omnicare, Inc. on September 20, 2002.*
(a)(1)(R) Motion for Summary Judgment as to Count I of the First Amended Complaint
filed in the Chancery Court, New Castle County, Delaware on September 30,
2002.*
(a)(1)(S) Motion to Dismiss the First Amended Complaint filed in the United States
District Court for the Northern District of Ohio on September 13, 2002.*
(a)(1)(T) Opposition to Omnicare's Motion to Dismiss and Motion for Preliminary
Injunction filed in the United States District Court for the Northern
District of Ohio on September 30, 2002.*
(a)(1)(U) Press Release issued by Omnicare, Inc. on October 4, 2002.*
(a)(1)(V) Defendant's Motion to Dismiss the Second Amended Complaint filed in the
Chancery Court, New Castle County, Delaware on October 3, 2002.*
(a)(1)(W) Omnicare's Reply Memorandum of Law in Further Support of the Motion to
Dismiss the First Amended Complaint filed in the United States District
Court for the Northern District of Ohio on October 15, 2002.*
(a)(1)(X) Second Amended Complaint filed in the Chancery Court, New Castle County,
Delaware on October 16, 2002.*
</Table>
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<Table>
(a)(1)(Y) Plaintiff's Memorandum of Law in Opposition to the NCS
Defendants' Motion to Dismiss Omnicare's Second Amended
Complaint filed in the Chancery Court, New Castle County,
Delaware on October 17, 2002.*
(a)(1)(Z) Omnicare's Memorandum of Law in Opposition to Plaintiff's
Motion for Preliminary Injunction filed in the United States
District Court for the Northern District of Ohio on October
17, 2002.*
(a)(1)(AA) The NCS Defendants' Memorandum of Law in Opposition to
Omnicare's and the Class Plaintiffs' Motion for Summary
Judgment filed in the Chancery Court, New Castle County,
Delaware on October 17, 2002.*
(a)(1)(BB) Defendant Jon H. Outcalt's Brief in Opposition to Omnicare's
Motion for Summary Judgment on Count I of the First Amended
Complaint filed in the Chancery Court, New Castle County,
Delaware on October 17, 2002.*
(a)(1)(CC) Defendant Kevin B. Shaw's Memorandum of Law in Opposition to
Omnicare's Motion for Summary Judgment on Count I of the
Second Amended Complaint filed in the Chancery Court, New
Castle County, Delaware on October 17, 2002.*
(a)(1)(DD) Brief of Defendants Genesis Health Ventures, Inc. and Geneva
Sub, Inc. in Opposition to Omnicare's and the Class
Plaintiffs' Motions for Summary Judgment on Count I of their
Complaints filed in the Chancery Court, New Castle County,
Delaware on October 17, 2002.*
(a)(1)(EE) Press Release issued by Omnicare, Inc. on October 22, 2002.*
(a)(1)(FF) Reply Memorandum of Law in Further Support of Omnicare's
Motion for Summary Judgment as to Count I of the Second
Amended Complaint filed in the Chancery Court, New Castle
County, Delaware on October 22, 2002.*
(a)(1)(GG) The NCS Defendants' Reply Memorandum of Law in Support of
Their Motion to Dismiss Omnicare's Second Amended Complaint
filed in the Chancery Court, New Castle County, Delaware on
October 22, 2002.*
(a)(1)(HH) Reply Brief of Defendants Genesis Health Ventures, Inc. and
Geneva Sub, Inc. in Support of Their Motion to Dismiss the
Second Amended Complaint filed in the Chancery Court, New
Castle County, Delaware on October 22, 2002.*
(a)(1)(II) Omnicare, Inc. v. NCS HealthCare, Inc., et al., C.A. No.
19800 (Del. Ch. October 25, 2002).*
(a)(1)(JJ) Press Release issued by Omnicare, Inc. on October 28, 2002.*
(a)(1)(KK) Omnicare, Inc. v. NCS HealthCare, Inc., et al., C.A. No.
19800 (Del. Ch. October 29, 2002).*
(a)(1)(LL) Press Release issued by Omnicare, Inc. on October 30, 2002.*
(a)(1)(MM) Excerpts from the Transcript of Omnicare's Third Quarter
2002 Conference Call, dated October 31, 2002.*
(a)(1)(NN) Press Release issued by Omnicare, Inc. on November 5, 2002.*
(a)(1)(OO) Selected material from a presentation of Omnicare, Inc. at
the CIBC World Markets 13th Annual Health Care Conference on
November 5, 2002 at The Plaza Hotel, New York, New York.*
(a)(1)(PP) Press Release issued by Omnicare, Inc. on November 19,
2002.*
(a)(1)(QQ) Brief filed by Omnicare, Inc. in the Supreme Court of the
State of Delaware on November 14, 2002.*
(a)(1)(RR) In Re NCS HealthCare, Inc., Shareholders Litigation,
Consolidated C.A. No. 19786 (Del. Ch. November 22, 2002).*
</Table>
<Page>
<Table>
(a)(1)(SS) Press Release issued by Omnicare, Inc. on November 25,
2002.*
(a)(1)(TT) Answering Brief filed by Appellees NCS HealthCare, Inc.,
Boake A. Sells and Richard L. Osborne in the Supreme Court
of the State of Delaware on November 22, 2002.*
(a)(1)(UU) Answering Brief filed by Appellees Jon H. Outcalt and Kevin
B. Shaw in the Supreme Court of the State of Delaware on
November 22, 2002.*
(a)(1)(VV) Answering Brief filed by Appellees Genesis Health Ventures,
Inc. and Geneva Sub, Inc. in the Supreme Court of the State
of Delaware on November 22, 2002.*
(a)(1)(WW) Press Release issued by Omnicare, Inc. on December 4, 2002.*
(a)(1)(XX) Order of the Supreme Court of the State of Delaware, issued
on December 3, 2002.*
(a)(1)(YY) Order of the Supreme Court of the State of Delaware, issued
on December 4, 2002.*
(a)(1)(ZZ) Press Release issued by Omnicare, Inc. on December 5, 2002.*
(a)(1)(AAA) Order of the Supreme Court of the State of Delaware, issued
on December 10, 2002.*
(a)(1)(BBB) Press Release issued by Omnicare, Inc. on December 11,
2002.*
(a)(1)(CCC) Omnicare, Inc. v. NCS HealthCare, Inc., et al., C.A. No.
19786 (Del. Ch. December 11, 2002).*
(a)(1)(DDD) Press Release issued by Omnicare, Inc. on December 12,
2002.*
(a)(1)(EEE) Rules and Procedures for Submission of Proposals for NCS
HealthCare, Inc., dated December 13, 2002.*
(a)(1)(FFF) Press Release issued by Omnicare, Inc. on December 16,
2002.*
(a)(1)(GGG) Press Release issued by Omnicare, Inc. on December 18,
2002.*
(a)(1)(HHH) Supplement to the Offer to Purchase dated December 23, 2002.*
(a)(1)(III) Revised Letter of Transmittal.*
(a)(1)(JJJ) Revised Notice of Guaranteed Delivery.*
(a)(1)(KKK) Revised Letter to Brokers, Dealers, Commercial Banks, Trust
Companies and Other Nominees.*
(a)(1)(LLL) Revised Letter to Clients for use by Brokers, Dealers,
Commercial Banks, Trust Companies and Other Nominees.*
(a)(1)(MMM) Guidelines for Certification of Taxpayer Identification
Number on Substitute Form W-9.*
(a)(1)(NNN) Press Release issued by Omnicare, Inc. on December 23, 2002.*
(a)(1)(OOO) Complaint filed by the stockholder-plaintiffs in the Court of
Chancery of the State of Delaware on December 27, 2002.*
(a)(1)(PPP) Motion for Temporary Restraining Order, together with (i)
Plaintiffs' Memorandum of Law in Support of Motion for Temporary
Restraining Order and (ii) the Affidavit of Joseph A. Rosenthal
in Support of Application for a Temporary Restraining Order,
filed by the stockholder-plaintiffs in the Court of Chancery of
the State of Delaware on December 27, 2002.*
(a)(5)(A) Form of Agreement and Plan of Merger proposed by Omnicare,
Inc.*
(a)(5)(B) Agreement and Plan of Merger executed by Omnicare, Inc.*
(a)(5)(C) Agreement and Plan of Merger executed and delivered by
Omnicare, Inc. on December 12, 2002.*
(a)(5)(D) Termination and Settlement Agreement, dated December 15,
2002, between Omnicare, Inc., Genesis Health Ventures, Inc.
and Geneva Sub, Inc.*
</Table>
<Page>
<Table>
(b)(1) Three-year, $495.0 million Credit Agreement, dated as of
March 20, 2001, among Omnicare, Inc., as the Borrower, the
Guarantors named therein and the lenders named therein, as
the Lenders, Lehman Commercial Paper Inc., as a Syndication
Agent, Sun Trust Bank, as a Documentation Agent, Deutsche
Banc Alex. Brown, as a Documentation Agent, and Bank One,
NA, with its main office in Chicago, Illinois, as the
Administrative Agent. (Incorporated by reference to Exhibit
99.3 of Omnicare's Current Report on Form 8-K filed with the
Securities and Exchange Commission on March 23, 2001).
(c) None.
(d)(1) Confidentiality Agreement, dated August 29, 2001, between
Omnicare, Inc. and NCS HealthCare, Inc.*
(d)(2) Agreement and Plan of Merger, dated December 17, 2002,
between Omnicare, Inc., NCS Acquisition Corp. and NCS
HealthCare, Inc.*
(e) None.
(f) None.
(g) None.
(h) None.
</Table>
- ---------
* Previously filed.