Carbapenem-resistant Klebsiella pneumoniae (CRKP) are recognised by the World Health Organisation as an urgent health threat in need of continued research into their resistance mechanisms, increased surveillance of prevalence and abundance, and novel drug development. Typical carbapenem-resistance in K. pneumoniae is multifaceted, complex, and yet achieved through well described resistance mechanisms such as drug inactivation by carbapenemases, the action of efflux pumps and/or porin mutations. Drug-resistant K. pneumoniae are well known to be prevalent pathogens within health-care settings, and only hypothesised to be the same within aged-care settings. This project aimed to measure the presence and burden of antimicrobial-resistant K. pneumoniae in aged-care settings in Adelaide, Australia. K. pneumoniae were isolated from resident, facility and wastewater samples on differential and selective media, with identification confirmed by MALDI-TOF MS. The antimicrobial susceptibility of K. pneumoniae isolates was determined using broth microdilution. A total of 207 K. pneumoniae were collected and 195 (94%) were shown to be resistant to at least one antimicrobial, 88 (42.5%) were multi-drug resistant and 8 (4%) were found to be resistant to both imipenem and meropenem. No carbapenemases were detected during PCR screening, and efflux pump inhibition showed no effect on carbapenem resistance. Whole-genome sequencing analysis confirmed an absence of carbapenemases and revealed uncharacterised mutations in key porins associated with antimicrobial resistance. Here we describe 8 CRKP with no readily apparent resistance mechanism(s) and with uncharacterised porin mutations. These findings challenge the current dogma regarding typical CRKP resistance. Further, this research provides new directions for research into the resistance mechanisms within CRKP.