Oak Street Health is part of CVS Healthspire™

Accountable Care Organization

Overview of the ACO

Oak Street Health Medicare Partners (“OSHMP”) is an Accountable Care Organization (ACO) led by Oak Street Health. Founded in 2012, Oak Street Health is a network of value-based primary care centers for adults on Medicare. With a mission of rebuilding healthcare as it should be, the Company operates an innovative healthcare model focused on quality of care over volume of services, and assumes the full financial risk of its patients. Oak Street Health currently operates more than 170 centers across 21 states and is the only primary care provider to carry the AARP name.

ACO Legal Business Name and Location

Oak Street Health Medicare Partners, LLC
30 W Monroe St, STE 1200
Chicago, IL 60603

ACO Primary Contact Information

  • Primary Contact Name: Kevin Slusarz, Director of Operations

  • Primary Contact Email: [email protected]

  • For beneficiary questions and voluntary alignment inquiries: (312) 366‑3463

ACO Participant Providers and Preferred Providers

ACO Joint Ventures

No joint ventures to report.

ACO Key Clinical and Administrative Leaders

  • Executive Officer: Robert Guenthner, Oak Street Health
  • Medical Director: Julie Silverstein M.D., Oak Street Health
  • Financial Officer: Timothy Cook, Oak Street Health
  • Quality Improvement: Michele Mitchell, M.D., Oak Street Health
  • Information Systems Officer: Tony Barton, Oak Street Health
  • Clinical Improvement Officer: Caroline Sommers, Oak Street Health
  • Clinical Data Steward: Drew Crenshaw, Oak Street Health
  • Compliance Officer: Michael Szott J.D., Oak Street Health
  • Personnel: Kevin Slusarz, Oak Street Health

ACO Governing Body

  • Ali Khan, M.D. (Chairman, Participant Provider, and Voting Member), Oak Street Health

  • Garfield Human (Beneficiary Representative and Voting Member), Retired

  • Laurine O’Donnell (Consumer Advocate and Voting Member), The Arbor Company

  • Michele Mitchell, M.D. (Participant Provider and Voting Member), Oak Street Health

  • David Buchanan, M.D. (Participant Provider and Voting Member), Oak Street Health

ACO Quality Measure Performance


  • 100%


  • Quality Measure Performance will be reported once available.

ACO Shared Savings and Shared Losses Information

This information is not yet available.


  • Shared Savings or Shared Losses: $14,628,161.32
  • Proportion of Shared Savings invested in infrastructure, redesigned care processes, and other resources necessary to improve outcomes and reduce Medicare cost for Beneficiaries: 100%
  • Proportion of Shared Savings distributed to Participant or Preferred Providers: 0%
  • Download the official results.


  • Shared Savings or Shared Losses will be reported once unavailable.

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