Exhibit 5.1

12531 HIGH BLUFF DRIVE
SAN DIEGO, CALIFORNIA
92130-2040   TELEPHONE: 858.720.5100 FACSIMILE: 858.720.5125   WWW.MOFO.COM MORRISON FOERSTER LLP   BEIJING, BERLIN, BRUSSELS, DENVER,
HONG KONG, LONDON, LOS ANGELES,
NEW YORK, NORTHERN VIRGINIA,
PALO ALTO, SACRAMENTO, SAN DIEGO,
SAN FRANCISCO, SHANGHAI, SINGAPORE,
TOKYO, WASHINGTON, D.C.

September 30, 2016

Fulgent Genetics, Inc.

4978 Santa Anita Avenue

Temple City, California 91780

Re:    Fulgent Genetics, Inc. 2016 Omnibus Incentive Plan

Ladies and Gentlemen:

At your request, we have examined the Registration Statement on Form S-8 (the “Registration Statement”) of Fulgent Genetics, Inc. (the “Company”) to be filed with the Securities and Exchange Commission in connection with the registration under the Securities Act of 1933, as amended, (the “Securities Act”), of an aggregate of 2,038,480 shares (the “Shares”) of the Company’s common stock, $0.0001 par value (the “Common Stock”), issuable under the Company’s 2016 Omnibus Incentive Plan (the “Plan”).

We have examined the originals, or photostatic or certified copies, of such records of the Company and certificates of officers of the Company and of public officials and such other documents as we have deemed relevant and necessary as the basis for rendering the opinion set forth below. In our examination, we have assumed the genuineness of all signatures, the legal capacity and competency of all natural persons, the authenticity of all documents submitted to us as originals and the conformity to original documents of all documents submitted to us as copies. For the purpose of the opinion rendered below, we have assumed that in connection with the issuance of the Shares, the Company will receive the consideration for such Shares required by the terms of the Plan, which shall be an amount not less than the aggregate par value of the Shares covered by each such issuance.

Based upon the foregoing examination and in reliance thereon, and subject to the qualifications, assumptions and limitations stated herein and in reliance on the statements of fact contained in the documents that we have examined, we are of the opinion that the Shares, when issued and sold in accordance with the terms set forth in the Plan, will be legally issued, fully paid and non-assessable shares of Common Stock.

We consent to the use of this opinion as an exhibit to the Registration Statement. In giving such consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act.

Very truly yours,

/s/ Morrison & Foerster LLP