(CBMX) Announces Contract With America’s Choice Provider Network(R)

Provides Access to Company’s Suite of Molecular Tests to Additional 14 Million Members Nationally

IRVINE, Calif., Nov. 21, 2013 — CombiMatrix Corporation (Nasdaq:CBMX), a molecular diagnostics company specializing in DNA-based testing services for developmental disorders and cancer diagnostics, today announced that it has entered into a contractual agreement with America’s Choice Provider Network^® (ACPN^®) for coverage of its diagnostic laboratory services.

The agreement with ACPN, a San Diego-based national healthcare savings provider network, provides access to CombiMatrix’s suite of molecular diagnostic solutions and comprehensive clinical support—specializing in prenatal, miscarriage and pediatric healthcare—to more than 14 million members.

About America’s Choice Provider Network (ACPN)

ACPN is a national healthcare savings provider network that offers providers an out-of‐network solution for over 540 payers. Its goals are to increase the business of its participating providers, create reasonable reimbursements and streamline payments. Across the nation, greater than 14 million Americans have access to ACPN’s National Provider Network through a client base consisting of Insurance Carriers, Third Party Administrators, Health and Welfare Funds, Employer Groups and Self‐Insured Health Plans. The products covered include Individual and Group Health, Workers Compensation, Auto Liability, and Medicare Advantage.

About CombiMatrix Corporation

CombiMatrix Corporation provides valuable molecular diagnostic solutions and comprehensive clinical support for the highest quality of care – specializing in miscarriage analysis, prenatal and pediatric healthcare. CombiMatrix offers comprehensive testing services for the detection of genetic abnormalities at the DNA level, beyond what can be identified through traditional methodologies. The Company performs genetic testing utilizing advanced technologies, including microarray, FISH, PCR and G-Band chromosome analyses. Additional information about CombiMatrix is available at www.combimatrix.com or by calling 1-800-710-0624.

Safe Harbor Statement under the Private Securities Litigation Reform Act of 1995

This press release contains forward-looking statements within the meaning of the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995. These statements are based upon our current expectations, speak only as of the date hereof and are subject to change. All statements, other than statements of historical fact included in this press release, are forward-looking statements. Forward-looking statements can often be identified by words such as “anticipates,” “expects,” “intends,” “plans,” “goal,” “predicts,” “believes,” “seeks,” “estimates,” “may,” “will,” “should,” “would,” “could,” “potential,” “continue,” “ongoing,” “objective,” similar expressions, and variations or negatives of these words and include, but are not limited to, statements regarding the access to our services for Blue KC members. These forward-looking statements are not guarantees of future results and are subject to risks, uncertainties and assumptions that could cause our actual results to differ materially and adversely from those expressed in any forward-looking statement. The risks and uncertainties referred to above include, but are not limited to: use of our services by America’s Choice Providers Network members; market acceptance of CMA as a preferred method over karyotyping; the rate of transition to CMA from karyotyping; our ability to successfully expand the base of our customers and strategic partners, add to the menu of our diagnostic tests in both of our primary markets, develop and introduce new tests and related reports, optimize the reimbursements received for our testing services, and increase operating margins by improving overall productivity and expanding sales volumes; our ability to successfully accelerate sales, allow access to samples earlier in the testing continuum, steadily increase the size of our customer rosters in both developmental medicine and oncology; our ability to attract and retain a qualified sales force; rapid technological change in our markets; changes in demand for our future products; legislative, regulatory and competitive developments; general economic conditions; and various other factors. Further information on potential factors that could affect our financial results is included in our Annual Report on Form 10-K, Quarterly Reports of Form 10-Q, and in other filings with the Securities and Exchange Commission. We undertake no obligation to revise or update publicly any forward-looking statements for any reason, except as required by law.

CONTACT: Company Contact:
         Mark McDonough
         President & CEO, CombiMatrix Corporation
         Tel (949) 753-0624

         Media Contact:
         Len Hall
         VP, Media Relations
         Allen & Caron
         Tel (949) 474-4300
         len@allencaron.com