Diabetes and prediabetes are prevalent chronic conditions that remain substantially underdiagnosed, particularly among populations with limited preventive healthcare engagement. Reliance on self-reported health status and previously known diagnoses therefore underestimates the true burden of glycaemic abnormalities within communities. Socioeconomically-vulnerable groups, including residents of public rental-housing, are at higher risk of missed screening and delayed linkage to primary care services.Community-based health-screening programmes provide a valuable platform to identify incidental glycaemic abnormalities and reveal gaps in primary care engagement. This study aimed to quantify the burden of incidentally detected glycaemic abnormalities in a socioeconomically-vulnerable population and to examine associations with primary care engagement.This cross-sectional study included 68 adult patients ≥40 years who participated in a health-screening programme conducted in a rental-housing estate with socioeconomically vulnerable residents. HbA1c testing was performed. Glycaemic status was classified using standard HbA1C criteria. Logistic regression was used to explore associations between incidental glycaemic abnormalities, prior screening history, and enrolment with GP clinics under HealthierSG, a national healthcare initiative.Mean age of participants was 62.3 years [±10.4], with equal sex distribution. Participants were predominantly Chinese[55.9%], followed by Malay[23.5%], Indian[11.8%], and other ethnicities[8.8%]. 38.2% of participants reported having at least one chronic condition [hypertension, diabetes, or hyperlipidaemia]. Most participants were not enrolled in HealthierSG [67.6%], and 47.1% had not received any health-screening in the last year. Mean HbA1c was 5.92% [±0.96]. 35.3% [24/68] had prediabetes, 19.1% [13/68] had diabetes, and 45.6% [31/68] were normoglycaemic. 84.6% of diabetes cases occurred in participants without prior diabetes diagnosis. Screening within the past year was not significantly associated with incidental glycaemic abnormalities [prediabetes, diabetes] compared with screening more than one year ago [OR=1.05;95%CI:0.32-3.42]. HealthierSG enrolment was not significantly associated with incidental dysglycaemia [OR=0.92;95%CI:0.33-2.55].Community-based screenings in rental-housing populations revealed a substantial burden of previously unrecognised glycaemic abnormalities, even among individuals with recent screening or primary-care enrolment. This suggests access alone may be insufficient for effective disease detection, likely influenced by competing social priorities, health literacy and follow-up challenges in socioeconomically vulnerable populations.Targeted community screening programmes may help address these gaps by enabling earlier diagnosis and improved linkage to primary care.