<Page> EXHIBIT 21 Subsidiaries of Omnicare, Inc. The following is a list of subsidiaries included in the consolidated financial statements of the Company as of December 31, 2004. Other subsidiaries which have been omitted from the list would not, when considered in the aggregate, constitute a significant subsidiary. Each of the companies is incorporated under the laws of the state following its name. State of Doing Business As Name Incorporation/ Legal Name (if other than legal name) Organization % Owned - ----------------------------------------------------------------------------------------------------------------------- AAHS Acquisition Corp. A-Avenue Health Services Delaware 100% Accu-Med Services of Washington LLC Delaware 100% Accu-Med Services, LLC Delaware 100% Alacritas Biopharma, Inc. California 90% Ambler Acquisition Company LLC Delaware 100% AMC - New York, Inc. Royal Care Holdings, Inc. Delaware 100% AMC - Tennessee, Inc. The Pharmacy, Stephens Drugs Delaware 100% Anderson Medical Services, Inc. Delaware 100% APS Acquisition LLC Delaware 100% Arlington Acquisition I, Inc. Delaware 100% Bach's Pharmacy (East), Inc. fka Pompton Nursing Home Suppliers Delaware 100% Bach's Pharmacy Services, LLC Delaware 100% Badger Acquisition LLC Delaware 100% Badger Acquisition of Brooksville LLC Delaware 100% Badger Acquisition of Kentucky LLC Delaware 100% Badger Acquisition of Minnesota LLC Delaware 100% Badger Acquisition of Ohio LLC Omnicare Health Network Delaware 100% Badger Acquisition of Orlando LLC Home Care Pharmacy of Florida Delaware 100% Badger Acquisition of Tampa LLC Bay Pharmacy Delaware 100% Badger Acquisition of Texas LLC Delaware 100% Bio-Pharm International, Inc. Delaware 100% BPNY Acquisition Corp. Brookside Park Pharmacy Delaware 100% BPTX Acquisition Corp. Brookside Park Pharmacy of Texas Delaware 100% Campo's Medical Pharmacy, Inc. Louisiana 100% Care Pharmaceutical Services, LP Delaware 100% CHP Acquisition Corp. Cherry Hill Pharmacy Delaware 100% CIP Acquisition Corp. Carter's Institutional Pharmacy Delaware 100% Clinimetrics Research Associates, Inc. California 100% CompScript - Boca, LLC Florida 100% CompScript - Mobile, Inc. Delaware 100% CompScript, Inc. Florida 100% CP Acquisition Corp. Central Pharmacy Oklahoma 100% Creekside Managed Care Pharmacy, Inc. Delaware 100% CTLP Acquisition LLC Care Tech Delaware 100% <Page> State of Doing Business As Name Incorporation/ Legal Name (if other than legal name) Organization % Owned - --------------------------------------------------------------------------------------------------------------------------- D & R Pharmaceutical Services, Inc. Kentucky 100% Dixon Pharmacy LLC Illinois 100% Enloe Drugs LLC Delaware 100% Euro Bio-Pharm Clinical Services, Inc. Delaware 100% Evergreen Pharmaceutical of California, Inc. fka PIP Acquisition, West Val Premiere California 100% Evergreen Pharmaceutical, Inc. Washington 100% Hardardt Group, Inc., The Delaware 100% Heartland Repack Services LLC Delaware 100% Highland Wholesale, LLC Ohio 100% HMIS, Inc. Delaware 100% Home Care Pharmacy, Inc. Delaware 100% Home Pharmacy Services, LLC Missouri 100% Hytree Pharmacy, Inc. Ohio 100% Interlock Pharmacy Systems, Inc. Missouri 100% JHC Acquisition LLC Jacobs Health Care Systems Delaware 100% Konsult, Inc. Delaware 100% Langsam Health Services, Inc. Sequoia Health Services, Inc. Delaware 100% LCPS Acquisition, LLC Medilife Pharmacy Delaware 100% Lobos Acquisition LLC Delaware 100% Lobos Acquisition of Arizona, Inc. Delaware 100% Lobos Acquisition of Pennsylvania, Inc. Delaware 100% Lo-Med Prescription Services, Inc. Ohio 100% LPA Acquisition Company, LLC Delaware 100% LPI Acquisition Corp. Lipira Pharmacy Delaware 100% Managed Healthcare, Inc. Delaware 100% Management & Network Services, Inc. Ohio 100% Med World Acquisition Corp. Delaware 100% Medical Arts Health Care, Inc. Georgia 100% Medical Services Consortium, Inc. Compscript - Miami Florida 100% MHHP Acquisition Company LLC Delaware 100% MOSI Acquisition Corp. Medical Outpatient Services Delaware 100% National Care For Seniors LLC Ohio 100% NCS Healthcare, Inc. Delaware 100% NCS Healthcare of Arizona, Inc. Ohio 100% NCS Healthcare of Arkansas, Inc. Ohio 100% NCS Healthcare of Beachwood, Inc. Ohio 100% NCS Healthcare of California, Inc. Ohio 100% NCS Healthcare of Connecticut, Inc. Connecticut 100% NCS Healthcare of Florida, Inc. Ohio 100% NCS Healthcare of Illinois, Inc. Illinois 100% <Page> State of Doing Business As Name Incorporation/ Legal Name (if other than legal name) Organization % Owned - --------------------------------------------------------------------------------------------------------------- NCS Healthcare of Indiana, Inc. Indiana 100% NCS Healthcare of Indiana, LLC Delaware 100% NCS Healthcare of Iowa, Inc. Ohio 100% NCS Healthcare of Kansas, Inc. Ohio 100% NCS Healthcare of Kentucky, Inc. Ohio 100% NCS Healthcare of Maryland, Inc. Ohio 100% NCS Healthcare of Massachusetts, Inc. Ohio 100% NCS Healthcare of Michigan, Inc. Ohio 100% NCS Healthcare of Minnesota, Inc. Ohio 100% NCS Healthcare of Missouri, Inc. Ohio 100% NCS Healthcare of Montana, Inc. Ohio 100% NCS Healthcare of New Hampshire, Inc. New Hampshire 100% NCS Healthcare of New Jersey, Inc. New Jersey 100% NCS Healthcare of New Mexico, Inc. Ohio 100% NCS Healthcare of New York, Inc. Ohio 100% NCS Healthcare of North Carolina, Inc. North Carolina 100% NCS Healthcare of Ohio, Inc. Ohio 100% NCS Healthcare of Oklahoma, Inc. Oklahoma 100% NCS Healthcare of Oregon, Inc. Ohio 100% NCS Healthcare of Pennsylvania, Inc. Pennsylvania 100% NCS Healthcare of Rhode Island, Inc. Rhode Island 100% NCS Healthcare of South Carolina, Inc. Ohio 100% NCS Healthcare of Tennessee, Inc. Ohio 100% NCS Healthcare of Texas, Inc. Ohio 100% NCS Healthcare of Vermont, Inc. Ohio 100% NCS Healthcare of Washington, Inc. Ohio 100% NCS Healthcare of Wisconsin, Inc. Ohio 100% NCS of Illinois, Inc. Ohio 100% NCS Services, Inc. Ohio 100% NGC Acquisition Company LLC Delaware 100% Nihan & Martin LLC Delaware 100% NIV Acquisition LLC Denman Pharmacy Services Delaware 100% North Shore Pharmacy Services, Inc. Delaware 100% OCR Services Corporation Delaware 100% OCR-RA Acquisition Corp. Long Term Care Pharmacy Delaware 100% OFL Corp. Delaware 100% Omnibill Services LLC Delaware 100% Omnicare Air Transport Services, Inc. Delaware 100% Omnicare Canadian Holdings, Inc. Delaware 100% Omnicare Clinical Research, Inc. fka IBAH, Inc. Delaware 100% <Page> State of Doing Business As Name Incorporation/ Legal Name (if other than legal name) Organization % Owned - --------------------------------------------------------------------------------------------------------------- Omnicare Clinical Research, LLC fka Coromed, Inc. Delaware 100% Omnicare CR Inc. Delaware 100% Omnicare Extended Pharma Services, LLC Delaware 100% Omnicare Headquarters LLC Delaware 100% Omnicare Holding Company Delaware 100% Omnicare Management Company Delaware 100% Omnicare of Nevada LLC Delaware 100% Omnicare Pennsylvania Med Supply, LLC Delaware 100% Omnicare Pharmacies of Maine Holding Company Delaware 100% Omnicare Pharmacies of Pennsylvania East, LLC Delaware 100% Omnicare Pharmacies of Pennsylvania West, Inc. Pennsylvania 100% Omnicare Pharmacies of the Great Plains Holding Company Delaware 100% Omnicare Pharmacy and Supply Services, Inc. South Dakota 100% Omnicare Pharmacy of Colorado LLC Delaware 100% Omnicare Pharmacy of Florida, LP Delaware 100% Omnicare Pharmacy of Indiana, LLC Delaware 100% Omnicare Pharmacy of Maine LLC Delaware 100% Omnicare Pharmacy of Nebraska LLC Delaware 100% Omnicare Pharmacy of North Carolina, LLC Delaware 100% Omnicare Pharmacy of Pueblo, LLC Delaware 100% Omnicare Pharmacy of South Dakota LLC Delaware 100% Omnicare Pharmacy of Tennessee LLC Delaware 100% Omnicare Pharmacy of Texas 1, LP Delaware 100% Omnicare Pharmacy of Texas 2, LP Delaware 100% Omnicare Pharmacy of the Midwest, Inc. fka Freed's Delaware 100% Omnicare Purchasing Company General Partner, Inc. Delaware 100% Omnicare Purchasing Company Limited Partner. Inc. Delaware 100% Omnicare Respiratory Services, LLC Delaware 100% Omnicare Senior Health Outcomes, LLC Delaware 100% Omnicare.com, Inc. Delaware 100% PBM-Plus, Inc. Wisconsin 100% PCI Acquisition, LLC Delaware 100% Pharmacon Corp. New York 100% Pharmacy Consultants, Inc. South Carolina 100% Pharmacy Holding # 1, LLC Delaware 100% Pharmacy Holding # 2, LLC Delaware 100% Pharmasource Healthcare, Inc. Georgia 100% Pharm-Corp of Maine LLC Delaware 100% Pharmed Holdings, Inc. Delaware 100% PRN Pharmaceutical Services, LP Delaware 100% Rescot Systems Group, Inc. Pennsylvania 100% <Page> State of Doing Business As Name Incorporation/ Legal Name (if other than legal name) Organization % Owned - --------------------------------------------------------------------------------------------------------------- Resource Biometrics, Inc. California 100% Roeschen's Healthcare Corp. Wisconsin 100% Royal Care of Michigan LLC Delaware 100% SHC Acquisition Co. LLC Synergy Delaware 100% Shore Pharmaceutical Providers, Inc. Delaware 100% Southside Apothecary, Inc. New York 100% Specialized Home Infusion of Michigan LLC Delaware 100% Specialized Patient Care Services, Inc. Alabama 100% Specialized Pharmacy Services, Inc. Michigan 100% Specialized Services of Michigan, Inc. Delaware 100% Sterling Healthcare Services, Inc. Delaware 100% Superior Care Pharmacy, Inc. Delaware 100% Swish, Inc. Delaware 100% TCPI Acquisition Corp. Total Care Pharmacy Delaware 100% THG Acquisition Corp. Tandem Health Group Delaware 100% Three Forks Apothecary, Inc. Kentucky 100% UC Acquisition Corp. UniCare, Inc. Delaware 100% Uni-Care Health Services of Maine, Inc. New Hampshire 100% Value Health Care Services, Inc. Delaware 100% Value Pharmacy, Inc. Massachusetts 100% Vital Care Infusions Supply, Inc. New York 100% Weber Medical Systems LLC Delaware 100% Westhaven Services Co. Ohio 100% Williamson Drug Company, Incorporated Virginia 100% Winslow's Pharmacy New Jersey 100% <Page> Country of Doing Business As Name Incorporation/ Legal Name (if other than legal name) Organization % Owned - --------------------------------------------------------------------------------------------------------------- Foreign Entities Country 3096479 Nova Scotia Company Canada 100% 3096480 Nova Scotia Company Canada 100% 3103-3798 Quebec, Inc. Omnicare Clinical Research Canada 100% 42986 Ontario Limited Medico Pharmacy Canada 100% Clinimetrics Research Australia, Pty, Ltd. Australia 100% Clinimetrics Research Canada, Inc. Canada 100% Clinimetrics Research Europe, Ltd. UK 100% De-Skor ZAO Russia 50% Omnicare Alberta LP Canada 100% Omnicare Clinical Research (Proprietary) Limited South Africa 100% Omnicare Clinical Research A/S Denmark 100% Omnicare Clinical Research A/B Sweden 100% Omnicare Clinical Research AG Switzerland 100% Omnicare Clinical Research Holdings B.V. Netherlands 100% Omnicare Clinical Research India Private Limited India 100% Omnicare Clinical Research International B.V. Netherlands 100% Omnicare Clinical Research GmbH Germany 100% Omnicare Clinical Research GmbH & Co. KG IFNS Germany 100% Omnicare Clinical Research Limited UK 100% Omnicare Clinical Research LLC Russia 100% Omnicare Clinical Research N.V. Belgium 100% Omnicare Clinical Research OY Finland 100% Omnicare Clinical Research PTE. LTD. Singapore 100% Omnicare Clinical Research PTY. LTD. Australia 100% Omnicare Clinical Research S.A. Argentina 100% Omnicare Clinical Research S.A.R.L. France 100% Omnicare Clinical Research S.L. Spain 100% Omnicare Clinical Research sp.z.oo Poland 100% Omnicare Clinical Research s.r.o Czech Republic 100%