Alzheimer's Disease is a degenerative, neurological disease in which cognitive function and memory decline. In this study, one diagnostic test was utilized to assess cognitive performance for participants in the Alzheimer’s Disease Neuroimaging Initiative (ADNI) over a follow up of 3-5 years. The Mini Mental State Examination (MMSE) is the most widely used cognitive screening test for dementia due to its quick testing time (7-10 minutes) and no requirement of specialized equipment or training for admission. Due to past literature reviews MMSE was found to have a lower sensitivity in detecting MCI and AD. Additional MMSE was shown to be highly influenced by education and age. These factors paired with MMSE’s lack of sensitivity for detecting MCI make it difficult to differentiate between those with mild Alzheimer's from normal patients. Our aim of our study was to determine the ability of MMSE to detect early MCI and to understand its reliability and efficacy in a clinical setting. Four groups of individuals were compared for their cognitive function changes based on MMSE: Healthy Control (HC), Early Mild Cognitive Impairment (EMCI), Late Mild Cognitive Impairment (LMCI) and Alzheimer's Disease (AD). We determined the results of the cohort after the 5 year follow up assessing cognitive performance by the MMSE test.