UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C. 20549

                                    FORM 13F

                              FORM 13F COVER PAGE

Report for the Calendar Year or Quarter Ended: MARCH 31, 2013
                                               --------------

Check here if Amendment [  ]; Amendment Number:
                                               --------------
     This Amendment (Check only one):      [  ] is a restatement.
                                           [  ] adds new holdings entries.

Institutional Investment Manager Filing this Report:

Name:          Castle Creek Capital Partners IV, LP
Address:       c/o Castle Creek Capital LLC
               6110 El Tordo
               Rancho Santa Fe, CA 92067

Form 13F File Number:  028-15339

The institutional investment manager filing this report and the person by whom
it is signed hereby represent that the person signing the report is authorized
to submit it, that all information contained herein is true, correct and
complete, and that it is understood that all required items, statements,
schedules, lists, and tables, are considered integral parts of this form.*

Person Signing this Report on Behalf of Reporting Manager:

Name:          William J. Ruh
Title:         Managing Principal
Phone:         (858) 756-8300

Signature, Place and Date of Signing:

/s/ William J. Ruh             Rancho Santa Fe, CA              May 14, 2013
------------------             -------------------              ------------
[Signature]                    [City, State]                    [Date]

* The Reporting Manager does not have formal investment discretion with respect
to all of the securities in the indicated rows, but may be deemed to be part of
a group exercising such investment discretion. Such group, if any, would include
the managers identified in the column captioned "Other Managers" relating to a
given issuer. The filing of this report shall not be deemed an admission, for
purposes of Section 13(f), 13(d), 13(g), or 16(a) under the Securities Exchange
Act of 1934, as amended (the "Exchange Act"), and the rules thereunder, or for
any other purpose, that the Reporting Manager or any Other Included Manager
exercises investment discretion or is a member of such a group with respect to
such securities. Reference is made to reports filed under Sections 13(d), 13(g),
and 16(a) for additional information with respect to such beneficial ownership
and/or pecuniary interest of the Reporting Manager, any Other Included Manager
and related entities.




Report Type (Check only one):

[X]   13F HOLDINGS REPORT.  (Check here if all holdings of this reporting
       manager are reported in this report.)

[ ]   13F NOTICE.  (Check here if no holdings reported are in this report, and
      all holdings are reported by other reporting manager(s).)

[ ]   13F COMBINATION REPORT.  (Check here if a portion of the holdings for this
      reporting manager are reported in this report and a portion are reported
      by other reporting manager(s).)




                             FORM 13F SUMMARY PAGE

Report Summary:

Number of Other Included Managers:          1

Form 13F Information Table Entry Total:     8

Form 13F Information Table Value Total:     $133,354 (in thousands)



List of Other Included Managers:

Provide a numbered list of the name(s) and Form 13F file number(s) of all
institutional investment managers with respect to which this report is filed,
other than the manager filing this report.

No.         Form 13F File Number          Name
---         --------------------          ----

1.          028-15366                     Castle Creek Capital IV LLC






                      Castle Creek Capital Partners IV, LP
                           FORM 13F INFORMATION TABLE
                          Quarter Ended March 31, 2013




                                                  FORM 13F INFORMATION TABLE

          COLUMN 1              COLUMN 2    COLUMN 3  COLUMN 4      COLUMN 5        COLUMN 6  COLUMN 7       COLUMN 8
---------------------------- -------------- --------- -------- ------------------- ---------- -------- --------------------
                                                       VALUE    SHRS OR   SH/ PUT/ INVESTMENT  OTHER     VOTING AUTHORITY
       NAME OF ISSUER        TITLE OF CLASS   CUSIP   (x$1000)  PRN AMT   PRN CALL DISCRETION MANAGERS SOLE   SHARED   NONE
---------------------------- -------------- --------- -------- ---------- --- ---- ---------- -------- ---- ---------- ----
                                                                                      
FIRST BANCORP N C            COM            318910106   13,002    963,794 SH       OTHER      1           0    963,794    0
FIRST MERCHANTS CORP         COM            320817109   21,557  1,394,747 SH       OTHER      1           0  1,394,747    0
GUARANTY BANCORP DEL         COM            40075T102   25,713 12,244,247 SH       OTHER      1           0 12,244,247    0
HERITAGE COMMERCE CORP       COM            426927109    8,805  1,308,300 SH       OTHER      1           0  1,308,300    0
HERITAGE OAKS BANCORP        COM            42724R107   14,154  2,483,100 SH       OTHER      1           0  2,483,100    0
INTERMOUNTAIN CMNTY BANCORP  COM NEW        45881M308   26,103  2,037,684 SH       OTHER      1           0  2,037,684    0
WASHINGTONFIRST BANKSHARES I COM            940730104    3,485    298,900 SH       OTHER      1           0    298,900    0
WEST COAST BANCORP ORE NEW   COM            952145209   20,517    845,000 SH       OTHER      1           0    845,000    0