BACKGROUND:Little is known about hospitalizationassociated disability (HAD) in older adults who receive care in safety-net hospitals. OBJECTIVES: To describe HAD and to examine its association with age in adults aged 55 and older hospitalized in a safety-net hospital. DESIGN: Secondary post hoc analysis of a prospective cohort from a discharge intervention trial, the Support from Hospital to Home for Elders. SETTING: Medicine, cardiology, and neurology inpatient services of San Francisco General Hospital, a safety-net hospital. PARTICIPANTS: A total of 583 participants 55 and older who spoke English, Spanish, or Chinese. We determined the incidence of HAD 30 days post-hospitalization and ORs for HAD by age group. MEASUREMENTS: The outcome measure was death or HAD at 30 days after hospital discharge. HAD is defined as a new or additional disability in one or more activities of daily living (ADL) that is present at hospital discharge compared to baseline. Participants' functional status at baseline (2 weeks prior to admission) and 30 days postdischarge was ascertained by self-report of ADL function. RESULTS: Many participants (75.3 %) were functionally independent at baseline. By age group, HAD occurred as follows: 27.4 % in ages 55-59, 22.2 % in ages 60-64, 17.4 % in ages 65-69, 30.3 % in ages 70-79, and 61.7 % in ages 80 or older. Compared to the youngest group, only the adjusted OR for HAD in adults over 80 was significant, at 2.45 (95 % CI 1.17, 5.15). CONCLUSIONS: In adults at a safety-net hospital, HAD occurred in similar proportions among adults aged 55-59 and those aged 70-79, and was highest in the oldest adults, aged ≥ 80. In safety-net hospitals, interventions to reduce HAD among patients 70 years and older should consider expanding age criteria to adults as young as 55.