Effective March 4, 2026, Corewell Health Laboratories in West Michigan will discontinue performing testosterone testing (LAB173 and LAB2111222) and Corewell Health Southwest Michigan will discontinue Testosterone Free and Total testing (LAB173)
The following replacements will be available as a send out to Quest Diagnostics:
⇒Testosterone, Total, MS – Epic Code: LAB1232313
⇒Testosterone, Free, Bioavailable and Total, MS – Epic Code: LAB1232237
As part of our ongoing transition to Quest Diagnostics as our primary reference laboratory, an update has been made to the saliva collection device used for cortisol testing.
Test: Cortisol, LC/MS, Saliva [Epic: LAB1232015, Interface: 1232015]
Approved Device: BLUE TOP Salivette® Cortisol Tube
Previously Accepted: White top tube
Status of White Top Tubes: No longer accepted – will be rejected
Action: Discard or return white top tubes and reorder blue top tubes via your supply form
Dear Valued Client:
We are pleased to announce that Corewell Health and Quest Diagnostics, a leading national laboratory company, have completed the formation of their laboratory services joint venture (JV) named Diagnostic Lab of Michigan, LLC.
This multifaceted collaboration will broaden access to innovative, high-value laboratory services for you and other providers in Michigan. Excitingly, work has begun on a new state-of-the-art laboratory in Southfield, Michigan, to service the JV. This laboratory will not be operational until the beginning of 2027. We will provide updates on the laboratory start date as work progresses.
Improving Access to Diagnostic Innovation in Michigan Over Time
Corewell Health and Quest Diagnostics share the goal to broaden access to quality, accessible and affordable laboratory services for providers and patients in Michigan. We expect Diagnostic Lab of Michigan to concentrate the shared resources and expertise of Corewell Health and Quest Diagnostics on improving access to diagnostic innovation in Michigan.
Over time, Diagnostic Lab of Michigan will provide several new benefits, including:
• Greater convenience for patients, as Corewell Health and Quest Diagnostics combine their patient service networks to reach more patients in Michigan.
• Michigan-grown diagnostic innovation, including through automation in the new laboratory.
• Broad health plan access to support patient affordability.
Your current Corewell Health Lab Account Representative will continue supporting you as part of the new joint venture laboratory. If you have questions, please contact Matt Boring, Sales Director, 248-345-5604.
We appreciate your business and look forward to the continuation of high-quality laboratory services for our patients, providers and communities.
Sincerely,
Sarah Britton
Vice President, Laboratory Services
Corewell Health
Go-Live Date: December 17, 2025
Following Phase One in November, where tests previously referred to ARUP and some Mayo Clinic Lab tests were transitioned to Quest Diagnostics, we are now moving into Phase Two of this important change. Corewell Health Laboratory is continuing its transition to Quest Diagnostics as our primary reference testing partner.
Effective November 19, 2025
Corewell Health Laboratory is transitioning to Quest Diagnostics as our primary reference testing laboratory. This change means that nearly all referral and send-out tests will now be performed by Quest Diagnostics. A limited number of tests will continue to be sent to other laboratories to ensure we meet the needs of our patients and clinicians.
We understand the significance of these changes and are committed to supporting your practice throughout this transition. Updates and modifications will be communicated promptly.
Please review the following letter regarding Corewell Health and Quest Diagnostics decision to Enter into Joint Venture: