OBJECTIVES: To investigate financial capacity in patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD) using a clinician interview approach. DESIGN: Cross-sectional. SETTING: Tertiary care medical center. PARTICIPANTS: Healthy older adults (n=75) and patients with amnestic MCI (n=58), mild AD (n=97), and moderate AD (n=31). MEASUREMENTS: The investigators and five study physicians developed a conceptually based, semistructured clinical interview for evaluating seven core financial domains and overall financial capacity (Semi-Structured Clinical Interview for Financial Capacity; SCIFC). For each participant, a physician made capacity judgments (capable, marginally capable, or incapable) for each financial domain and for overall capacity. RESULTS: Study physicians made more than 11,000 capacity judgments across the study sample (N=261). Very good interrater agreement was obtained for the SCIFC judgments. Increasing proportions of marginal and incapable judgment ratings were associated with increasing disease severity across the four study groups. For overall financial capacity, 95% of physician judgments for older controls were rated as capable, compared with 82% for patients with MCI, 26% for patients with mild AD, and 4% for patients with moderate AD. CONCLUSION: Physicians and other clinicians can reliably evaluate financial capacity in cognitively impaired older adults using a relatively brief, semistructured clinical interview. Patients with MCI have mild impairment in financial capacity, those with mild AD have emerging global impairment, and those with moderate AD have advanced global impairment. Patients with MCI and their families should proactively engage in financial and legal planning, given these patients' risk of developing AD and accelerated loss of financial abilities. © 2009, The American Geriatrics Society.