MCAF Mountain Crest Acquisition Corporation IV

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

Under the Securities Exchange Act of 1934

(Amendment No. 2)*

Mountain Crest Acquisition Corp. IV

(Name of Issuer)

Common Stock, $0.0001 par value per share

(Title of Class of Securities)

62403K108

(CUSIP Number)

December 31, 2022

(Date of Event which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

☐ Rule 13d-1(b)

☒ Rule 13d-1(c)

☐ Rule 13d-1(d)

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

(Continued on the Following Pages)

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CUSIP No. 62403K108

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CUSIP No. 62403K108

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CUSIP No. 62403K108

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This Amendment No. 2 (“Amendment No. 2”) is filed pursuant to Rule 13d-2(b) promulgated under the Securities Exchange Act of 1934, as amended, with respect to the Common Stock, $0.0001 par value per share (the “Shares”), of Mountain Crest Acquisition Corp. IV (the “Issuer”) beneficially owned by the Reporting Persons specified herein as of December 31, 2022, and amends and supplements the Schedule 13G filed November 18, 2021 as amended by Amendment No. 1 thereto filed February 2, 2022 (collectively, the “Schedule 13G”). Except as set forth herein, the Schedule 13G is unmodified.

The names of the persons filing this statement on Amendment No. 2 are: Linden Capital L.P., a Bermuda limited partnership (“Linden Capital”), Linden Advisors LP, a Delaware limited partnership (“Linden Advisors”), Linden GP LLC, a Delaware limited liability company (“Linden GP”), and Mr. Siu Min (Joe) Wong (“Mr. Wong,” and collectively, the “Reporting Persons”).

As of December 31, 2022, each of Linden Advisors and Mr. Wong may be deemed the beneficial owner of 511,333 Shares. This amount consists of 481,724 Shares held by Linden Capital and 29,609 Shares held by separately managed accounts. As of December 31, 2022, each of Linden GP and Linden Capital may be deemed the beneficial owner of the 481,724 Shares held by Linden Capital.

As of December 31, 2022, each of Linden Advisors and Mr. Wong may be deemed the beneficial owner of approximately 6.8% of Shares outstanding, and each of Linden GP and Linden Capital may be deemed the beneficial owner of approximately 6.4% of Shares outstanding. These percentages are based on 7,557,000 Shares outstanding based on disclosures by the issuer in its quarterly report on Form 10-Q filed on November 14, 2022.

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Not applicable.

By signing below, the undersigned certifies that, to the best of its knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under Sec. 240.14a-11.

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SIGNATURES

After reasonable inquiry and to the best of its knowledge and belief, each of the undersigned certifies that the information with respect to it set forth in this statement is true, complete, and correct.

Dated: January 30, 2023