13D Filing: James E. Flynn and Adeptus Health Inc. (ADPT)

This Amendment No. 4 (this “Amendment”)
to Schedule 13D amends the Schedule 13D (as previously amended, the “Schedule 13D”) filed by (i) Deerfield Mgmt,
L.P. (“Deerfield Mgmt”), (ii) Deerfield Management Company, L.P. (“Deerfield Management”),
(iii) Deerfield Partners, L.P. (“Deerfield Partners”), (iv) Deerfield International Master Fund, L.P. (“DIMF”
and, together with Deerfield Partners, collectively referred to herein as the “Funds”) and (v) James E. Flynn,
a natural person (“Flynn” and, collectively with Deerfield Mgmt, Deerfield Management, Deerfield Partners, and
DIMF, the “Reporting Persons”), with respect to the securities of Adeptus Health Inc. (the “Company”),
on September 19, 2016, as amended by Amendment Nos. 1, 2 and 3 thereto, filed by the Reporting Persons on February 6, 2017, April
4, 2017 and April 20, 2017, respectively.

Capitalized terms used herein but not otherwise
defined herein shall have the meanings ascribed to them in the Schedule 13D.

Item 4.     Purpose of Transaction.

Item 4 of the Schedule 13D is hereby
supplemented and amended as follows:

The information set
forth under Item 6 of this Amendment is incorporated herein by reference.

Item 5.     Interests in Securities of the
Issuer

Item 5 of the Schedule 13D is hereby
amended and restated in its entirety to read as follows:

(a) Throughout this report, the percentage
of outstanding Common Stock beneficially owned by the Reporting Persons has been determined based on 16,395,599 shares of Common
Stock outstanding as of November 7, 2016, as set forth in the Company’s Quarterly Report on Form 10-Q for the quarterly period
ended September 30, 2016.

(1) Deerfield Management

Number of shares: 798,297

Percentage of shares: 4.87%

(2) Deerfield Mgmt

Number of shares: 798,297

Percentage of shares: 4.87%

(3) Deerfield Partners

Number of shares: 351,252

Percentage of shares: 2.14%

(4) DIMF

Number of shares: 447,045

Percentage of shares: 2.73%