SCHEDULE 13G/A 0001692115 XXXXXXXX LIVE 3 Common Stock, par value $0.01 per share 07/08/2025 0001981599 Centuri Holdings, Inc. 155923105 19820 North 7th Avenue, Suite 120 Phoenix AZ 85027 Rule 13d-1(d) Southwest Gas Holdings, Inc. DE 46185710.00 0.00 46185710.00 0.00 46185710.00 N 52.1 CO Centuri Holdings, Inc. 19820 North 7th Avenue, Suite 120, Phoenix, Arizona 85027 Southwest Gas Holdings, Inc. 8360 S. Durango Dr. Post Office Box 98510, Las Vegas, Nevada 89113 Delaware Y The information set forth in the cover page of this Schedule 13G is incorporated herein by reference. The percentage ownership reflected in line 11 in the cover page of this Schedule 13G is based on 88,649,154 shares of Common Stock outstanding as of June 13, 2025, as reported as reported by the Issuer in its final prospectus dated June 16, 2025 and filed with the Securities and Exchange Commission on June 17, 2025 pursuant to Rule 424(b)(4) under the Securities Act of 1933, as amended. 52.1 46,185,710 0 46,185,710 0 Y Y Y Y Y Y Southwest Gas Holdings, Inc. /s/ Catherin M. Mazzeo 07/08/2025