Continuous glucose monitors

Medical policy

Continuous Glucose Monitoring - 91466

Commercial and Medicaid patients


Prior authorization is required for insulin pumps, continuous glucose monitors and supplies obtained by DME.

Participating providers: Use our Auth Request tool, which will direct your request for healthcare review. In many cases, an authorization number can be provided immediately. Authorization requests must be submitted annually for ongoing approval of pump supplies.

Non-participating providers: Request authorizations using the general Medical prior authorization form.

When authorization isn't required

Continuous glucose monitors – Freestyle Libre and Dexcom – obtained though pharmacy by Commercial and Individual product members don't require prior authorization.

Medicare patients


The Centers for Medicare & Medicaid Services' (CMS) Ruling 1682R addresses the benefit category for non-adjunctive Continuous Glucose Monitoring (CGM) systems. This ruling classifies CGM systems into therapeutic and non-therapeutic systems:

  • A non-therapeutic CGM device is used as an adjunct to blood glucose monitoring (i.e., primary therapeutic decisions regarding diabetes treatment must be made with a standard home blood glucose monitor, not the CGM).
  • A therapeutic CGM is defined as a replacement for fingerstick blood glucose testing for diabetes treatment decisions, i.e., non-adjunctive use. At this time the Dexcom G5® Mobile Continuous Glucose Monitoring (CGM) System is the only FDA-approved CGM device classified with a "non-adjunctive" indication.

Medicare continuous glucose monitor coverage

Dexcom G6® Mobile Continuous Glucose Monitoring (CGM) and the Freestyle Libre are the only therapeutic CGMs covered by Medicare. At this time, all other CGM systems are classified by CMS as non-therapeutic CGM systems and are not covered.

Coverage is retroeffective back to January 12, 2017.

For more details, see Local Coverage Determination 38822 and links, including limits, for Glucose Monitors, on the CMS website.

Medical criteria

CGS, the DME Medicare Administrative Contractor (MAC) with jurisdiction for the State of Michigan, has established the following criteria that members must meet to qualify for Dexcom G6®:

  • The member has diabetes mellitus; and,
  • The member is insulin-treated with multiple daily injections (MDI) of insulin or a continuous subcutaneous insulin infusion (CSII) pump; and,
  • The member's insulin treatment regimen requires frequent adjustment by the beneficiary on the basis of therapeutic CGM testing results; and,
  • Within six (6) months prior to ordering the CGM, the treating practitioner has an in-person visit with the beneficiary to evaluate their diabetes control and determined that criteria (1-3) above are met; and,
  • Every six (6) months following the initial prescription of the CGM, the treating practitioner has an in-person visit with the beneficiary to assess adherence to their CGM regimen and diabetes treatment plan.

Medicare coverage for supplies used with the Dexcom G6® Mobile CGM System

Supplies are covered, including all items necessary for the use of the device but not limited to: CGM sensor, CGM transmitter, home blood glucose monitor and related BGM supplies (test strips, lancets, lancing device, and calibration solutions) and all batteries.

A monthly supply allowance is covered for Medicare members who have a Dexcom G6® Mobile CGM System and who meet the coverage requirements outlined on this page.

Coverage of the CGM system supply allowance is limited to those therapeutic CGM systems where the beneficiary ONLY uses a receiver classified as DME to display glucose data.

Medicare CGM monitor and supplies authorizations

You will need to request a pre-service organization determination (PSOD) if prescribing or filling more than the approved limit of diabetes testing supplies. The provider should:

  • Document if a member is not insulin dependent
  • Document that a PSOD must be completed, which is equivalent to original Medicare's Advance Beneficiary Notice (ABN).
Go to the Authorizations section for details on Medicare non-coverage/PSODs.

Medicare CGM billing


When the monitor prescribed is a therapeutic continuous glucose monitor (the Dexcom G6 CGM system or Freestyle Libre), and

When the patient meets all coverage criteria in effect on the date of service of the initial claim.

Not payable:

Non-DME devices (smart phone, tablet, etc.) used as the display device, either separately or in combination with a receiver classified as DME; these are considered by Medicare to be non-medical items even if serving a medical purpose.

Medical supplies used with non-covered equipment

Equipment or supplies/accessories obtained prior to Medicare eligibility

Member cost share

The Dexcom G6 and Freestyle Libre and supplies fall under the member's Priority Health Medicare DME benefit. Applicable member cost share, depending on the member's plan, applies to both the device and supplies.


Refer to the medical policy and LCD, above.

Applicable HCPCS modifiers for glucose monitors and supplies:

  • CG - Policy criteria applied
  • EY - No physician or other licensed health care provider order for this item or service 
  • KS - Glucose monitor supply for diabetic beneficiary not treated by insulin
  • KX - Requirements specified in the medical policy have been met