Lack of health insurance is a public health crisis, leading to foregone care and financial strain. Hospital Presumptive Eligibility (HPE) is a hospital-based emergency Medicaid program that provides temporary (up to 60d) coverage, with the goal that hospitals will assist patients in applying for ongoing Medicaid coverage. It is unclear whether HPE is associated with successful longer-term Medicaid enrollment. To characterize Medicaid enrollment 6 months after initiation of HPE and determine sociodemographic, clinical, and geographic factors associated with Medicaid enrollment. This was a cohort study of all HPE approved inpatients in California, using claims data from the California Department of Healthcare Services. The study was conducted across all HPE-participating hospitals within California between January 1, 2016 and December 31, 2017. We studied California adult hospitalized inpatients, who were uninsured at the time of hospitalization and approved for HPE emergency Medicaid. Using multivariable logistic regression models, we compared HPE-approved patients who enrolled in Medicaid by 6 months versus those who did not. HPE emergency Medicaid approval at the time of hospitalization. The primary outcome was full-scope Medicaid enrollment by 6 months after the hospital's presumptive eligibility approval. Among 71,335 inpatient HPE recipients, a total of 45,817 (64.2%) enrolled in Medicaid by 6 months. There was variability in Medicaid enrollment across counties in California (33%-100%). In adjusted analyses, Spanish-preferred-language patients were less likely to enroll in Medicaid (aOR 0.77, P <0.001). Surgical intervention (aOR 1.10, P <0.001) and discharge to another inpatient facility or a long-term care facility increased the odds of Medicaid enrollment (vs. routine discharge home: aOR 2.24 and aOR 1.96, P <0.001). California patients who enroll in HPE often enroll in Medicaid coverage by 6 months, particularly among patients requiring surgical intervention, repeated health care visits, and ongoing access to care. Future opportunities include prospective evaluation of HPE recipients to understand the impact that Medicaid enrollment has on health care utilization and financial solvency.