IMPORTANCE: Collaborative dementia care programs are effective in addressing the needs of patients with dementia and their caregivers. However, attempts to consider effects on health care spending have been limited, leaving a critical gap in the conversation around value-based dementia care.

OBJECTIVE: To determine the effect of participation in collaborative dementia care on total Medicare reimbursement costs compared with usual care.

DESIGN, SETTING, AND PARTICIPANTS: This was a prespecified secondary analysis of the Care Ecosystem trial, a 12-month, single-blind, parallel-group randomized clinical trial conducted from March 2015 to March 2018 at 2 academic medical centers in California and Nebraska. Participants were patients with dementia who were living in the community, aged 45 years or older, and had a primary caregiver and Medicare fee-for-service coverage for the duration of the trial.

INTERVENTION: Telehealth dementia care program that entailed assignment to an unlicensed dementia care guide who provided caregiver support, standardized education, and connection to licensed dementia care specialists.

MAIN OUTCOMES AND MEASURES: Primary outcome was the sum of all Medicare claim payments during study enrollment, excluding Part D (drugs).

RESULTS: Of the 780 patients in the Care Ecosystem trial, 460 (59.0%) were eligible for and included in this analysis. Patients had a median (IQR) age of 78 (72-84) years, and 256 (55.7%) identified as female. Participation in collaborative dementia care reduced the total cost of care by $3290 from 1 to 6 months postenrollment (95% CI, -$6149 to -$431; P = .02) and by $3027 from 7 to 12 months postenrollment (95% CI, -$5899 to -$154; P = .04), corresponding overall to a mean monthly cost reduction of $526 across 12 months. An evaluation of baseline predictors of greater cost reduction identified trends for recent emergency department visit (-$5944; 95% CI, -$10 336 to -$1553; interaction P = .07) and caregiver depression (-$6556; 95% CI, -$11 059 to -$2052; interaction P = .05).

CONCLUSIONS AND RELEVANCE: In this secondary analysis of a randomized clinical trial among Medicare beneficiaries with dementia, the Care Ecosystem model was associated with lower total cost of care compared with usual care. Collaborative dementia care programs are a cost-effective, high-value model for dementia care.

TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02213458.