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Laboratory Services

Corewell Health System, Southeast Michigan, Southwest Michigan, West Michigan

Update on Corewell Health and Quest Diagnostics Joint Venture

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

Corewell Letter to Clients Close

January 6, 2026 by
General Information, Southwest Michigan, West Michigan

Outpatient Laboratory Hours of Operation Update

Effective January 1, 2026, the following outpatient laboratory (PSC’s) hours will be updated.

 

Corewell Health Big Rapids Hospital Laboratory   

605 Oak St., Big Rapids, 49307

Monday to Friday: 6:30 a.m. to 6 p.m.; Saturday: 7 a.m. to 11 a.m.

 

Corewell Health Gerber Hospital Laboratory – Newaygo

211 W. Pine Lake Drive, Newaygo, 49337

Monday to Thursday: 7 a.m. to noon.,12:30 p.m. to 3 p.m.; Friday: 7 a.m. to noon

 

Corewell Health Greenville Hospital Laboratory

615 S. Bower St., Greenville, 4883

Monday to Friday: 6:30 a.m. to 6 p.m.; Saturday: 7 a.m. to 11 a.m.

 

Corewell Health Greenville Hospital Laboratory – Lakeview 

8650 W Howard City-Edmore Road, Lakeview, 48850

Monday to Friday: 7 a.m. to 3:30 p.m.; Saturday: 8 a.m. to noon

 

Corewell Health Lakeland Hospitals Laboratory – Niles   

31 N. St. Joseph Ave., Niles, 49120

Monday to Friday: 6:30 a.m. to 5 p.m.; Saturday: 7 a.m. to 11 a.m.

 

Corewell Health Pennock Hospital Laboratory

1009 W. Green St., Hastings, 49058

Monday to Friday: 6 a.m. to 6 p.m.; Saturday: 7 a.m. to 11 a.m.

 

Corewell Health Pennock Hospital Laboratory – Lake Odessa 

4294 Laurel Drive, Lake Odessa, 48849

Monday to Friday: 7 a.m. to 3 p.m.

 

Corewell Health Reed City Hospital Laboratory

300 N. Patterson Road, Reed City, 49677

Monday to Friday: 6:30 a.m. to 6 p.m.; Saturday: 7 a.m. to 11 a.m.

 

Corewell Health Watervliet Hospital Laboratory 

400 Medical Park Drive, Watervliet, 49098

Monday to Friday: 7 a.m. to 3:30 p.m.

 

Corewell Health Zeeland Hospital Laboratory

8333 Felch St., Zeeland, 49464

Monday to Friday: 6 a.m. to 6 p.m.; Saturday: 7 a.m. to 11 a.m.

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December 30, 2025 by
Referral/Sendouts

Send Out Referral Testing Update: Phase Two Transition to Quest Diagnostics

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.

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December 10, 2025 by
Referral/Sendouts, Southeast Michigan

Meconium Drug Screen Testing Update

Effective December 3, 2025, meconium drug screen testing for Southeast Michigan will transition from ARUP to Corewell Health Reference Laboratory West.

This change ensures consistent, high-quality testing across all Corewell Health regions and clinically standardizes the services we provide as a system.

What’s Changing:

Southeast Michigan specimens will now be tested at Corewell Health Reference Laboratory West

Collection and transport processes remain unchanged.

Purpose of Test:

Meconium drug screen testing detects and documents fetal drug exposure during approximately the last trimester of a full-term pregnancy

For more information, please refer to the Lab Test Directory: Meconium Drug Testing LAB479

November 26, 2025 by
Chemistry, West Michigan

Specimen Type Change for Outpatient Chemistry Tests – Effective December 3, 2025

Updated: 11/26/2025

Effective Date: December 3, 2025

What’s Changing?

The preferred specimen type for most outpatient Chemistry tests will change from: Lithium Heparin Gel PST (mint green-top with gel) to Serum Separator SST (gold-top with gel)

Gray-top tube (Potassium Oxalate & Sodium Fluoride) will now be the preferred tube for glucose testing. Gold-top SST will remain acceptable for glucose testing and preferred for panels that contain glucose testing.

Why the Change?

SST tubes provide improved specimen quality and stability, supporting more accurate test results.

Gray-top tubes contain additives that prevent glycolysis, ensuring more accurate glucose measurements.

Key Points

Gold-top SST is now the preferred tube for outpatient Chemistry specimens.

Light green-top PST will still be accepted for the respective tests.

Gray-top is the preferred tube for glucose testing; gold-top is acceptable and should still be used for panels containing glucose.

Resources

View Complete Test List

Updated Preferred Tube Quick Guide

Lab Catalog

(Note: This change only impacts West Michigan; Southeast and Southwest Michigan sites already use gold-top SST tubes for many of these tests.)

Questions?

Use the Contact Us link above.

November 21, 2025 by
General Information, West Michigan

Update: Laboratory Requisition Shipping Timeline – Please Plan Ahead

We want to share an important update regarding the shipping timeline for requisition orders.

As part of our ongoing efforts to streamline operations and improve service delivery, Corewell Health has transitioned to a new external printing vendor for requisition materials. While this change supports long-term efficiency, it does come with a temporary adjustment in turnaround time.

Requisition shipments will now take up to 12 business days to arrive, which is a longer timeframe than previously experienced.

To help ensure your office remains fully stocked and avoids any supply interruptions, we recommend placing orders at least three weeks in advance of running out of requisitions.

We appreciate your understanding and cooperation as we adapt to this new process. If you have any questions or need support with ordering, please don’t hesitate to reach out.

Thank you for your continued partnership!

November 7, 2025 by
Referral/Sendouts, Southeast Michigan, Southwest Michigan, West Michigan

Primary Reference Lab Change to Quest Diagnostics

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.

What You Need to Know:

  • Test Crosswalks: Tests currently performed at ARUP and Mayo Clinic Labs will be matched to comparable tests at Quest Diagnostics.
  • Discontinued Tests: Tests with low utilization or those no longer deemed clinically necessary will be discontinued.
  • New LAB Numbers: All tests will receive new LAB numbers, which must be updated in your EMR compendium if interfaced.
  • Collection Devices: Some tests may require different collection devices.
  • Transition Timeline:
    • November 19, 2025: Focus on tests currently referred to ARUP.
    • December 17, 2025: Focus on tests currently referred to Mayo Clinic Labs.
  • Crosswalk Resources: Crosswalks between current and future test offerings will be provided to help you prepare.
  • Test Directory Access: Please refer to your regional Lab Test Directory for details on specific test changes. ARUP and Mayo Clinic Lab test pages will include links to the corresponding Quest Diagnostic tests.

We understand the significance of these changes and are committed to supporting your practice throughout this transition. Updates and modifications will be communicated promptly.

Contact Information:

  • Corewell Health East Sendouts: 248.551.9045
  • Corewell Health West Referrals: 616.267.2753
  • Or use the Contact Us link above.
October 27, 2025 by