Plasmid-mediated AmpC β-lactamases (PMACBLs) have been reported in Escherichia coli, Klebsiella, Salmonella, and Proteus, with genes originating from chromosomally encoded AmpC β-lactamases in other Enterobacteriaceae and typically conferring resistance to all β-lactams except fourth-generation cephalosporins and carbapenems. Here, we report two novel PMACBLs identified in cefoxitin-resistant E. coli isolates from New Zealand: strains ARL05-909 and ARL06-39, isolated in 2005 from the urine of elderly, hospitalized patients on antibiotic treatment. Using multiplex PCR, the PMACBL genes were identified as CMY-2-like; the entire CMY gene was amplified and sequenced, and amino acid sequences compared to GenBank showed both were novel, designated CMY-29 (ARL05-909) and CMY-30 (ARL06-39) by the Lahey Clinic. CMY-29 is most closely related to CMY-7, differing by an Ile141Phe substitution; CMY-30 is most closely related to CMY-2, differing by a Val231Gly substitution, with DNA sequences showing single-point mutations from CMY-7 (GenBank AJ011291) and CMY-2 (GenBank X91840), respectively. Susceptibility tested via CLSI methods showed expected β-lactam patterns for PMACBLs. Isoelectric focusing of crude extracts revealed only β-lactamase with a pI of 9.0. Southern blot confirmed both genes were on plasmids. CMY-29 and CMY-30 are the first novel PMACBLs in New Zealand, closely related to CMY-7 and CMY-2 (the only other CMY-2-like PMACBLs there), with CMY-2 being the most prevalent in the country.