File Nos. 002-76969

811-03445

As filed with the Securities and Exchange Commission

on September 27, 2021

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-1A

THE MERGER FUND

(Exact Name of Registrant as Specified in Charter)

100 Summit Lake Drive

Valhalla, New York 10595

(Address of principal executive offices)

(914) 741-5600

(Registrant's telephone number, including area code)

Roy D. Behren and Michael T. Shannon

The Merger Fund

100 Summit Lake Drive

Valhalla, New York 10595

(Name and address of agent for Service)

with copies to:

Jeremy Smith, Esq.

Ropes & Gray LLP

1211 Avenue of the Americas

New York, New York 10036

It is proposed that this filing will become effective:

If appropriate, check the following box:

EXPLANATORY NOTE

Pursuant to Rule 485(b)(1)(iii) of the Securities Act of 1933, the sole purpose of this Post-Effective Amendment No. 73 to the Registration Statement of The Merger Fund (the “Registrant”) is to designate a new effective date of the Post-Effective Amendment No. 72, which was filed on August 18, 2021. Post-Effective Amendment No. 72 designated a new effective date of the Post-Effective Amendment No. 71, which was filed on July 2, 2021 (Accession No. 0001104659-21-088936). Parts A, B and C of Post-Effective Amendment No. 71 are unchanged and are hereby incorporated by reference.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, and the Investment Company Act of 1940, as amended, the Registrant certifies that it meets all of the requirements of this Registration Statement under Rule 485(b) under the Securities Act of 1933 and has duly caused this Post-Effective Amendment No. 73 to its Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Valhalla and State of New York, on the 27th day of September, 2021.

Pursuant to the requirements of the Securities Act, this Post-Effective Amendment No. 73 to Registrant’s Registration Statement has been signed below by the following persons in the capacities and on the dates indicated.