EX-99.906 CERT 3 d804833dex99906cert.htm CERTIFICATION PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT

Exhibit 99.906CERT

Certification Pursuant to 18 U.S.C. 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002; provided by the Chief Executive Officer and Chief Financial Officer, based on each such officer’s knowledge and belief.

The undersigned officers of Nuveen California Select Tax-Free Income Portfolio (the “Fund”) certify that, to the best of each such officer’s knowledge and belief:

| 1. |  | The Form N-CSR of the Fund for the period ended February 29, 2024 (the “Report”) fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

| 2. |  | The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Fund.

Date: May 3, 2024

/s/ David J. Lamb
David J. Lamb
Chief Administrative Officer
(principal executive officer)
/s/ E. Scott Wickerham
E. Scott Wickerham
Vice President and Controller
(principal financial officer)