For any item to be covered by Medicare, it must 1) be eligible for a defined
Medicare benefit category, 2) be reasonable and necessary for the diagnosis or
treatment of illness or injury or to improve the functioning of a malformed
body member, and 3) meet all other applicable Medicare statutory and
regulatory requirements.

The purpose of a Local Coverage Determination (LCD) is to provide information
regarding "reasonable and necessary" criteria based on Social Security Act 
1862(a)(1)(A) provisions.

In addition to the "reasonable and necessary" criteria contained in this LCD
there are other payment rules, which are discussed in the following documents,
that must also be met prior to Medicare reimbursement:

  * The LCD-related Standard Documentation Requirements Article, located at the bottom of this policy under the Related Local Coverage Documents section.

  * The LCD-related Policy Article, located at the bottom of this policy under the Related Local Coverage Documents section.

  * Refer to the Supplier Manual for additional information on documentation requirements.

  * Refer to the DME MAC web sites for additional bulletin articles and other publications related to this LCD.

For the items addressed in this LCD, the "reasonable and necessary" criteria,
based on Social Security Act  1862(a)(1)(A) provisions, are defined by the
following coverage indications, limitations and/or medical necessity.  
  
HOME BLOOD GLUCOSE MONITORS (BGM)  
  
To be eligible for coverage of home blood glucose monitors and related
accessories and supplies, the beneficiary must meet both of the following
basic criteria (1) - (2):

  1. The beneficiary has diabetes (Refer to the ICD-10 code list in the LCD-related Policy Article for applicable diagnoses); and

  2. The beneficiary's treating practitioner has concluded that the beneficiary (or the beneficiary's caregiver) has sufficient training using the particular device prescribed as evidenced by providing a prescription for the appropriate supplies and frequency of blood glucose testing.

For all glucose monitors and related accessories and supplies, if the basic
coverage criteria (1)-(2) are not met, the item(s) will be denied as not
reasonable and necessary.

Home blood glucose monitors with special features (HCPCS codes E2100, E2101)
are covered when the basic coverage criteria (1)-(2) are met and the treating
practitioner certifies that the beneficiary has a severe visual impairment
(i.e., best corrected visual acuity of 20/200 or worse in both eyes) requiring
use of this special monitoring system.

Code E2101 is also covered for those with impairment of manual dexterity when
the basic coverage criteria (1)-(2) are met and the treating practitioner
certifies that the beneficiary has an impairment of manual dexterity severe
enough to require the use of this special monitoring system. Coverage of code
E2101 for beneficiaries with manual dexterity impairments is not dependent
upon a visual impairment.

If a glucose monitor (code E2100 or E2101) is provided and basic coverage
criteria (1)-(2) plus the additional criteria stated above are not met, it
will be denied as not reasonable and necessary.

Lancets (code A4259), blood glucose test reagent strips (code A4253), glucose
control solutions (code A4256) and spring powered devices for lancets (code
A4258) are covered for beneficiaries for whom the glucose monitor is covered.

More than one spring powered device (code A4258) per 6 months is not
reasonable and necessary.

The medical necessity for a laser skin piercing device (code E0620) and
related lens shield cartridge (code A4257) has not been established;
therefore, claims for code E0620 and/or code A4257 will be denied as not
reasonable and necessary.

The quantity of test strips (code A4253) and lancets (code A4259) that are
covered depends on the usual medical needs of the beneficiary and whether or
not the beneficiary is being treated with insulin, regardless of their
diagnostic classification as having Type 1 or Type 2 diabetes mellitus.
Coverage of testing supplies is based on the following guidelines:  
  
Usual Utilization

For a beneficiary who is not currently being treated with insulin
administrations, up to 100 test strips and up to 100 lancets every 3 months
are covered if the basic coverage criteria (1)-(2) (above) are met.

For a beneficiary who is currently being treated with insulin administrations,
up to 300 test strips and up to 300 lancets every 3 months are covered if
basic coverage criteria (1)-(2) (above) are met.  
  
High Utilization

For a beneficiary who is not currently being treated with insulin
administrations, more than 100 test strips and more than 100 lancets every 3
months are covered if criteria (a) - (c) below are met.

For a beneficiary who is currently being treated with insulin administrations,
more than 300 test strips and more than 300 lancets every 3 months are covered
if criteria (a) - (c) below are met.

  1. Basic coverage criteria (1)-(2) listed above for all home glucose monitors and related accessories and supplies are met; and,

  2. Within the six (6) months prior to ordering quantities of strips and lancets that exceed the utilization guidelines, the treating practitioner has had an in-person visit with the beneficiary to evaluate their diabetes control and their need for the specific quantity of supplies that exceeds the usual utilization amounts described above; and,

  3. Every six (6) months, for continued dispensing of quantities of testing supplies that exceed the usual utilization amounts, the treating practitioner must verify adherence to the high utilization testing regimen.

If neither basic coverage criterion (1) or (2) is met, all testing supplies
will be denied as not reasonable and necessary. If quantities of test strips
or lancets that exceed the utilization guidelines are provided and criteria
(a) - (c) are not met, the amount in excess will be denied as not reasonable
and necessary.  
  
CONTINUOUS GLUCOSE MONITORS (CGM)

The general term CGM refers to both therapeutic/non-adjunctive and non-
therapeutic/adjunctive CGMs. For the purpose of this LCD, the term
"therapeutic" may be used interchangeably with the term "non-adjunctive."
Likewise, the term "non-therapeutic" may be used interchangeably with the term
"adjunctive."

A therapeutic or non-adjunctive CGM can be used to make treatment decisions
without the need for a stand-alone BGM to confirm testing results. A non-
therapeutic or adjunctive CGM requires the user verify their glucose levels or
trends displayed on a CGM with a BGM prior to making treatment decisions. On
February 28, 2022, CMS determined that both therapeutic/non-adjunctive and
non-therapeutic/adjunctive CGMs may be classified as DME.

Refer to the NON-MEDICAL NECESSITY COVERAGE AND PAYMENT RULES and CODING
GUIDELINES sections in the LCD-related Policy Article for additional
information regarding classification of CGMs as DME.

To be eligible for coverage of a CGM and related supplies, the beneficiary
must meet all of the following initial coverage criteria (1)-(5):

  1. The beneficiary has diabetes mellitus (Refer to the ICD-10 code list in the LCD-related Policy Article for applicable diagnoses); and,

  2. The beneficiary's treating practitioner has concluded that the beneficiary (or beneficiary's caregiver) has sufficient training using the CGM prescribed as evidenced by providing a prescription; and,

  3. The CGM is prescribed in accordance with its FDA indications for use; and,

  4. The beneficiary for whom a CGM is being prescribed, to improve glycemic control, meets at least one of the criteria below:

  1.     1. The beneficiary is insulin-treated with at least one daily administration of insulin; or,

    2. The beneficiary has a history of problematic hypoglycemia with documentation of at least one of the following:

  *     *       * Recurrent level 2 hypoglycemic events (glucose <54mg/dL (3.0mmol/L) that persist despite multiple (2 or more) attempts to adjust medication(s) and/or modify the diabetes treatment plan; or

      * A history of one level 3 hypoglycemic event (glucose <54mg/dL (3.0mmol/L) characterized by altered mental and/or physical state requiring third-party assistance for treatment of hypoglycemia

  5. Within six (6) months prior to ordering the CGM, the treating practitioner has an in-person or Medicare-approved telehealth visit with the beneficiary to evaluate their diabetes control and determined that criteria (1-4) above are met.

CGM Continued Coverage

Every six (6) months following the initial prescription of the CGM, the
treating practitioner conducts an in-person or Medicare-approved telehealth
visit with the beneficiary to document adherence to their CGM regimen and
diabetes treatment plan.

When a CGM (code K0554 or E2102) is covered, the related supply allowance
(code K0553 or A4238) is also covered. Supplies (code A4238) for an adjunctive
CGM integrated into an external insulin infusion pump are covered when the
beneficiary meets both the CGM coverage criteria and the coverage criteria for
an external insulin infusion pump. Refer to the External Infusion Pumps LCD
(L33794) for additional information regarding billing a CGM receiver
incorporated into an insulin infusion pump.

If any of the initial coverage criteria (1-5), or the continued coverage
criterion are not met, the CGM and related supply allowance will be denied as
not reasonable and necessary.

The supply allowance (code K0553 or A4238) is billed as one (1) unit of
service (UOS) per thirty (30) days. Only one (1) UOS of code K0553 or A4238
may be billed to the DME MACs at a time. Billing more than one (1) UOS per
thirty (30) days of code K0553 or A4238 will be denied as not reasonable and
necessary. Refer to the CODING GUIDELINES section in the LCD-related Policy
Article for additional billing instructions.

Non-adjunctive CGM devices replace standard home BGMs (HCPCS codes E0607,
E2100, E2101) and related supplies (HCPCS codes A4233, A4234, A4235, A4236,
A4244, A4245, A4246, A4247, A4250, A4253, A4255, A4256, A4257, A4258, A4259).
Claims for a BGM and related supplies, billed in addition to a non-adjunctive
CGM device (code K0554) and associated supply allowance (code K0553), will be
denied.

Adjunctive CGM devices do not replace a standard home BGM. The supply
allowance for an adjunctive CGM (A4238) encompasses all items necessary for
the use of the device and includes but is not limited to, CGM sensors and
transmitters. Code A4238 does not include a home BGM and related BGM testing
supplies. These items may be billed separately, in addition to code A4238.
Refer to the CODING GUIDELINES section in the LCD-related Policy Article for
additional information.

All CGM devices billed to Medicare using HCPCS code K0554 must be reviewed for
correct coding by the Pricing, Data Analysis and Coding (PDAC) contractor and
be listed on the Product Classification List (PCL). Effective July 1, 2022,
all CGMs billed to Medicare using HCPCS code E2102 must be reviewed for
correct coding by the PDAC contractor and be listed on the PCL. If a CGM
system is billed using HCPCS code K0554 or E2102 (effective July 1, 2022) but
the CGM system is not on the PCL for the particular HCPCS code, then the claim
will be denied as incorrect coding. Refer to the CODING GUIDELINES section in
the LCD-related Policy Article for additional information.  
  
GENERAL

A Standard Written Order (SWO) must be communicated to the supplier before a
claim is submitted. If the supplier bills for an item addressed in this policy
without first receiving a completed SWO, the claim shall be denied as not
reasonable and necessary.

For Durable Medical Equipment, Prosthetics, Orthotics and Supplies (DMEPOS)
base items that require a Written Order Prior to Delivery (WOPD), the supplier
must have received a signed SWO before the DMEPOS item is delivered to a
beneficiary. If a supplier delivers a DMEPOS item without first receiving a
WOPD, the claim shall be denied as not reasonable and necessary. Refer to the
LCD-related Policy Article, located at the bottom of this policy under the
Related Local Coverage Documents section.

For DMEPOS base items that require a WOPD, and also require separately billed
associated options, accessories, and/or supplies, the supplier must have
received a WOPD which lists the base item and which may list all the
associated options, accessories, and/or supplies that are separately billed
prior to the delivery of the items. In this scenario, if the supplier
separately bills for associated options, accessories, and/or supplies without
first receiving a completed and signed WOPD of the base item prior to
delivery, the claim(s) shall be denied as not reasonable and necessary.

An item/service is correctly coded when it meets all the coding guidelines
listed in CMS HCPCS guidelines, LCDs, LCD-related Policy Articles, or DME MAC
articles. Claims that do not meet coding guidelines shall be denied as not
reasonable and necessary/incorrectly coded.

Proof of delivery (POD) is a Supplier Standard and DMEPOS suppliers are
required to maintain POD documentation in their files. Proof of delivery
documentation must be made available to the Medicare contractor upon request.
All services that do not have appropriate proof of delivery from the supplier
shall be denied as not reasonable and necessary.  
  
REFILL REQUIREMENTS  
  
For DMEPOS items and supplies provided on a recurring basis, billing must be
based on prospective, not retrospective use. For DMEPOS products that are
supplied as refills to the original order, suppliers must contact the
beneficiary prior to dispensing the refill and not automatically ship on a
pre-determined basis, even if authorized by the beneficiary. This shall be
done to ensure that the refilled item remains reasonable and necessary,
existing supplies are approaching exhaustion, and to confirm any changes or
modifications to the order. Contact with the beneficiary or designee regarding
refills must take place no sooner than 14 calendar days prior to the
delivery/shipping date. For delivery of refills, the supplier must deliver the
DMEPOS product no sooner than 10 calendar days prior to the end of usage for
the current product. This is regardless of which delivery method is utilized.

For all DMEPOS items that are provided on a recurring basis, suppliers are
required to have contact with the beneficiary or caregiver/designee prior to
dispensing a new supply of items. Suppliers must not deliver refills without a
refill request from a beneficiary. Items delivered without a valid, documented
refill request will be denied as not reasonable and necessary.

Suppliers must not dispense a quantity of supplies exceeding a beneficiary's
expected utilization. Suppliers must stay attuned to changed or atypical
utilization patterns on the part of their clients. Suppliers must verify with
the treating practitioner that any changed or atypical utilization is
warranted.

Regardless of utilization, a supplier must not dispense more than a three (3)
month quantity of BGM testing supplies at a time.

Refill requirements do not apply to code K0553 or A4238. Only one (1) UOS of
code K0553 or A4238 may be billed to the DME MACs at a time and no more than a
90-day supply may be dispensed to the beneficiary at a time. Refer to the
CODING GUIDELINES section in the LCD-related Policy Article for additional
billing instructions.

**Background**

Diabetes mellitus describes diseases of abnormal carbohydrate metabolism
characterized by hyperglycemia that are associated with an absolute or
relative impairment in insulin secretion, peripheral resistance to the action
of insulin, or both. According to the Centers for Disease Control (CDC)
National Diabetes Statistics Report 2022, the estimated prevalence of diabetes
for 2019 in the US was 37.3 million people or 11.3% of the population. The
percentage of adults with diabetes increases with age, reaching 29.2% among
those aged 65 years or older.1

Continuous glucose monitoring (CGM) devices measure the glucose content of
interstitial fluid every 1 to 15 minutes, depending on the device.
Interstitial fluid is accessed by a sensor inserted subcutaneously by the
patient and worn for up to 14 days. A transmitter is attached to the sensor or
worn over the sensor and transmits the glucose data to a receiver/smartphone.
CGM systems provide visualization of the current glucose value as well as
trend analysis, which indicates the direction of changing glucose. This
technology can help patients fine-tune diabetic treatment. There are two main
types of CGM systems: real time CGM (RT-CGM) and devices that require
intermittent scanning, also known as flash continuous glucose monitoring
(FGM).

CGMs are designated by the Food and Drug Administration (FDA) as either
adjunctive or non-adjunctive. A non-adjunctive CGM can be used to make
treatment decisions without the need for a stand-alone home blood glucose
monitor to confirm testing results. Non-adjunctive CGMs can be either RT-CGM
or FGM technology. Adjunctive CGMs are CGMs that beneficiaries use to check
their glucose levels and trends which must be verified by use of a blood
glucose monitor to make diabetes treatment decisions.

The aim of this summary of evidence was to determine if the application of CGM
technology (adjunctive and non-adjunctive) will improve health outcomes for
diabetic Medicare beneficiaries who do not administer insulin 3 times daily,
evidenced by a clinically significant reduction in HbA1c, increased time in
range, or a reduction in rate or severity of hypoglycemic events compared to
self-monitoring of blood glucose (SMBG). For this analysis, hypoglycemic
events were classified as one of three levels consistent with the ADA
Standards for Medical Care in 20222:

  * _Level 1 hypoglycemia is defined as a measurable glucose concentration <70 mg/dL (3.9 mmol/L) but 54 mg/dL (3.0 mmol/L)_
  * _Level 2 hypoglycemia (defined as a blood glucose concentration <54 mg/dL [3.0 mmol/L]) _
  * _Level 3 hypoglycemia is defined as a severe event characterized by altered mental and/or physical functioning that requires assistance from another person for recovery_

The summary of evidence specifically addresses requests for coverage of CGM
during pregnancy, for patients with chronic kidney disease (CKD) stage 3-5,
and for patients with other rare causes of hypoglycemia. Additionally, the
summary of evidence outlines the appropriateness of requiring in-person
physician visits every six months to support continued need of the CGM, the
allowance for telehealth visits, and limitations on billing the supply
allowance monthly versus quarterly.

**Food and Drug Administration (FDA) Approvals**

Dexcom G6 Continuous Glucose Monitoring System:
<https://www.accessdata.fda.gov/cdrh_docs/reviews/DEN170088.pdf>

Freestyle Libre Flash Glucose Monitoring System:
<https://www.accessdata.fda.gov/cdrh_docs/pdf16/P160030A.pdf>

Freestyle Libre 2 Flash Glucose Monitoring System:
<https://www.accessdata.fda.gov/cdrh_docs/reviews/K193371.pdf>

Medtronic Guardian Connect System:
<https://www.accessdata.fda.gov/cdrh_docs/pdf16/P160007A.pdf>

**Literature Analysis**

**CGM for beneficiaries with diabetes administering insulin 1-2 times daily**

Four randomized controlled trials (RCTs)3-6 and one observational trial7
assessed the effects of CGM on HbA1c and/or Time in Range (TIR) in type 2
diabetes mellitus (T2DM) patients administering basal insulin. Ehrhardt et
al.4 conducted a prospective, 12-week, two-arm RCT which compared RT-CGM (n =
50) versus SMBG (n = 50) in people with T2DM not taking prandial insulin with
an initial HbA1c  7%. HbA1c decreased by 1.0% (1.1%) for the RT-CGM group
and 0.5% (0.8%) for the SMBG group at 12 weeks ( _p_ = 0.006).4 The RT-CGM
group had an adjusted decline in HbA1c of 0.60% greater than the SMBG group (
_p =_ 0.002).4 Vigersky et al.6 conducted a 40-week follow-up study which
showed the significant difference in HbA1c between CGM and SMBG was sustained
during the 40-week follow-up time period. Martens et al.5 conducted an
8-month, open-label, 2:1 randomized, multicenter, clinical trial across 15
centers which evaluated the effectiveness of CGM (n=116) versus SMBG (n=59) in
T2DM patients treated with only basal insulin. At the 8-month follow-up, the
mean HbA1c levels decreased from 9.1% in the CGM group and 9.0% in the SMBG
group to 8.0% vs. 8.4%, respectively (adjusted difference in mean change in
HbA1c -0.4% [95%CI, -0.8% to - 0.1%] _p_ = 0.02.5 In the CGM group, compared
with the SMBG group, the mean percentage of time at 70 to 180 mg/dL was 59% vs
43% (adjusted mean difference, 15% [95% CI, 8% to 23%]; _p_ < 0.001;
equivalent to 3.6 hours more per day).5 A 6-month extension study conducted by
Aleppo et al.3 aimed to determine the long-term benefits of continued CGM use
or the detriments of discontinuing CGM. Upon completion of the 8-month visit
for the initial RCT5, participants in the CGM group were randomly assigned to
either discontinue CGM (n=53) or continue CGM (n=53) at a 1:1 ratio with the
primary outcome being TIR.3 In the discontinue CGM group, mean TIR 70-180
mg/dL, which improved from 38% before initiating CGM to 62% after 8 months of
CGM use, decreased after discontinuing CGM to 50% at 14 months (mean change
from 8 to 14 months -12% [95% CI -21% to -3%], _p_ = 0.01).3 In the group that
continued CGM use, little change was found in TIR from 8 to 14 months
(baseline 44%, 8 months 56%, 14 months 57%, mean change from 8 to 14 months 1%
[95% CI -11% to 12%], _p_ = 0.89).3 Comparing the two groups at 14 months, the
adjusted treatment group difference in mean TIR was -6% (95% CI -16% to 4%,
_p_ = 0.20).3 These studies3-6 included several limitations such as relatively
small sample sizes, missing data for some participants during the follow-up
periods, and the possibility of confounding.

A retrospective non-interventional single-arm chart review7 investigated the
change in HbA1c in T2DM patients using only basal insulin and commencing use
of a FGM monitoring system. Eligible medical records ( _n_ = 103) from six
diabetes centers in Canada showed HbA1c significantly decreased by 0.8%  1.1
mean  SD (95% confidence interval for change -1.1 to -0.6 [9.1 mmol/mol 
12.1, 11.6 to 6.6], _p_ < 0.0001) from baseline HbA1c 8.9%  0.9 (74.1
mmol/mol  9.7) to 8.1%  1.0 (65.0 mmol/mol  10.5) 3-6 months after
initiation of FGM use.7 Several limitations exist including relatively small
sample size, lack of a comparator (such as SMBG), short study duration, and
the possibility of confounded results due to inclusion of patients making drug
therapy changes.

Two prospective clinical trials assessed the patterns of hypoglycemia and
glycemic variability in adult patients with insulin treated and non-insulin
treated T2DM.8,9 In a study conducted by Munshi et al.9, a blinded CGM
measured interstitial glucose levels at intervals of 5 minutes for a 3-day
period while T1DM (n=12) or T2DM (n=28) participants conducted their usual
daily activities and conducted SMBG 4 times a day.9 Of a total of 102
hypoglycemic episodes, 95 (93%) were unrecognized by SMBG or symptoms despite
only 2 patients reporting "hypoglycemia unawareness". In a study conducted by
Gehault et al.8, a total of 108 patients with T2DM wore a blinded CGM for 5
days which tracked the severity, timing, and the number of hypoglycemic events
while the participants kept daily 4-point SMBG logs and tracked any self-
perceived hypoglycemic episodes.8 Episodes of hypoglycemia were detected in
49.1% (53 of 108 patients), which extrapolated out to 1.74  SD 2.54 episodes
per patient per 5 days of CGM.8 Out of the 53 patients who had hypoglycemic
episodes, 10 (18.9%) were on none of the medications that typically cause
lows. The majority (75%) of patients were not aware of their hypoglycemic
episodes detected by CGM ( _p_ < 0.001).8 Both studies were limited by the
observational design, use of a professional CGM as opposed to a personal CGM,
short study duration, and a relatively small heterogenous sample which
included insulin and non-insulin treated diabetics.8,9

Three systematic reviews with meta-analyses (SRMAs) attempted to examine the
efficacy of CGM use in patients with T2DM compared to SMBG.10-12 CGM was
associated with a significant reduction in HbA1c levels for the combination of
T2DM patients (insulin and non-insulin treated) in all three SRMAs. 10-12 Only
one SRMA reported data related to hypoglycemia with the combined CGM group
from 3 trials exhibiting shorter time spent with hypoglycemia than the SMBG
group (SMD, 0.35; 95% CI, 0.59 to 0.10; _p_ = 0.006; I2 = 0% _p_ = 0.86).10

The American Diabetes Association (ADA) Standards of Medical Care in Diabetes
202213 specify that RT-CGM (Grade: A) or intermittently scanned continuous
glucose monitoring (isCGM) (Grade: C) can be used for diabetes management in
adults with diabetes on basal insulin who are capable of using devices safely.
The choice of device should be made based on patient circumstances, desires,
and needs.13 The Endocrine Society Clinical Practice Guideline for the
treatment of diabetes in older adults in 201914 recommends frequent
fingerstick glucose monitoring and/or continuous glucose monitoring (to assess
glycemia) for patients aged 65 years and older with insulin treated diabetes.

The American Association of Clinical Endocrinology (AACE) Clinical Practice
Guideline on the use of Advanced Technology in the Management of Persons with
Diabetes Mellitus in 202115 recommends CGM for all individuals with
problematic hypoglycemia (frequent/severe hypoglycemia, nocturnal
hypoglycemia, hypoglycemia unawareness) (Grade A; Intermediate-High Strength
of Evidence; BEL 1). The AACE guideline further states that CGM may be
recommended for individuals with T2DM who are treated with less intensive
insulin therapy. (Grade B; Intermediate Strength of Evidence; BEL 1).15 The
AACE and American College of Endocrinology Consensus Conference on Continuous
Glucose Monitoring in 201616 unanimously agreed that RT-CGM should be
available to all insulin-using patients regardless of diabetes type, however
this conclusion was based entirely on studies conducted in type 1 diabetes
mellitus (T1DM) at the time of the recommendation.

The Diabetes Canada Clinical Practice Guidelines for 201817 indicate that FGM
may be offered to people with diabetes to decrease time spent in hypoglycemia
[Grade B, Level 2 for type 1 diabetes; Grade B, Level 2 for type 2 diabetes].
The National Institute for Health and Care Excellence (NICE) guidelines for
202218 suggest offering a CGM to adults with insulin-treated T2DM who would
otherwise need help from a care worker or healthcare professional to monitor
their blood glucose.

**CGM for beneficiaries with T2DM not administering insulin (oral hypoglycemic
agents only)**

A 24-week, multicenter, open-label, randomized parallel-group trial19
evaluated the effects of flash glucose monitoring (FGM) and conventional SMBG
on HbA1c in patients with non-insulin-treated T2DM. At 24 weeks, HbA1c was
significantly decreased from baseline values in the FGM group, but not in the
SMBG group (FGM: 0.46% (5.0 mmol/mol), 95% CI 0.59 to 0.32, p < 0.001;
SMBG: 0.17% (1.8 mmol/mol), 95% CI 0.05 to 0.11, _p_ = 0.124); a
significant statistical between-group difference in this respect was observed
0.29% (3.2 mmol/mol), 95% CI 0.54 to 0.05; _p_ =0.022). The authors
concluded that among patients with non-insulin treated T2DM, glycemic control
was better with FGM than with SMBG after cessation of glucose monitoring.
Several limitations exist including the small sample size, short study
duration (24 weeks), non-evaluation of lifestyle changes of enrolled
participants, and non-fixed antidiabetic drugs throughout the study.
Additionally, the slight reduction in HbA1c may not be clinically significant
or long lasting.

Two prospective clinical trials assessed the patterns of hypoglycemia and
glycemic variability in adult patients with insulin treated and non-insulin
treated T2DM.8,9 In a study conducted by Munshi et al.9, a blinded CGM
measured interstitial glucose levels at intervals of 5 minutes for a 3-day
period while T1DM (n=12) or T2DM (n=28) participants conducted their usual
daily activities and conducted SMBG 4 times a day.9 Of a total of 102
hypoglycemic episodes, 95 (93%) were unrecognized by SMBG or symptoms despite
only 2 patients reporting "hypoglycemia unawareness". In a study conducted by
Gehault et al.8, a total of 108 patients with T2DM wore a blinded CGM for 5
days which tracked the severity, timing, and the number of hypoglycemic events
while the participants kept daily 4-point SMBG logs and tracked any self-
perceived hypoglycemic episodes.8 Episodes of hypoglycemia were detected in
49.1% (53 of 108 patients), which extrapolated out to 1.74  SD 2.54 episodes
per patient per 5 days of CGM.8 Out of the 53 patients who had hypoglycemic
episodes, 10 (18.9%) were on none of the medications that typically cause
lows. The majority (75%) of patients were not aware of their hypoglycemic
episodes detected by CGM ( _p_ < 0.001).8 Both studies were limited by the
observational design, use of a professional CGM as opposed to a personal CGM,
short study duration, and a relatively small heterogenous sample which
included insulin and non-insulin treated diabetics.8,9

Three systematic reviews with meta-analyses (SRMAs) attempted to examine the
efficacy of CGM use in patients with T2DM compared to SMBG.10-12 CGM was
associated with a significant reduction in HbA1c levels for the combination of
T2DM patients (insulin and non-insulin treated) in all three SRMAs.10-12 Only
one SRMA reported data related to hypoglycemia with the combined CGM group
from 3 trials exhibiting shorter time spent with hypoglycemia than the SMBG
group (SMD, 0.35; 95% CI, 0.59 to 0.10; _p_ = 0.006; I2 = 0% ( _p_ =
0.86)).10

The ADA "Standards of Medical Care in Diabetes" for 202213 specifies that
periodic use of RT-CGM or isCGM or use of professional CGM can be helpful for
diabetes management in circumstances where continuous use of CGM is not
appropriate, desired, or available. (Grade: C) Additionally, the ADA
"Standards of Medical Care in Diabetes" Chapter 6 indicates that "recurrent
level 2 hypoglycemia and/or level 3 hypoglycemia is an urgent medical issue
and requires intervention with medical regimen adjustment, behavioral
intervention, and, in some cases, use of technology to assist with
hypoglycemia prevention and identification".2

The AACE Clinical Practice Guideline on the use of Advanced Technology in the
Management of Persons with Diabetes Mellitus in 202115 recommends CGM for all
individuals with problematic hypoglycemia (frequent/severe hypoglycemia,
nocturnal hypoglycemia, hypoglycemia unawareness). (Grade A; Intermediate-High
Strength of Evidence; BEL 1) The Diabetes Canada Clinical Practice Guidelines
for 201817 state that FGM may be offered to people with diabetes to decrease
time spent in hypoglycemia [Grade B, Level 2 for type 2 diabetes]. The AACE
and American College of Endocrinology Consensus Conference on Continuous
Glucose Monitoring in 201616 included that T2DM patients who use
antihyperglycemic agents other than insulin might also benefit from CGM, but
the evidence base was inadequate to make a strong recommendation.

**CGM for beneficiaries with diabetes and chronic kidney disease (CKD) stage
3-5**

A systematic review20 evaluated the role of intensive glucose control in the
development of renal end points in T2DM patients (n=28,065) based on the
results of seven clinical trials. The meta-analysis concluded that intensive
glucose control reduces the risk for microalbuminuria and macroalbuminuria,
but evidence is lacking that intensive glycemic control reduces the risk for
significant clinical renal outcomes, such as doubling of the serum creatinine
level, end-stage renal disease (ESRD), or death from renal disease during the
years of follow-up of the trials. The meta-analysis did not compare the use of
SMBG to CGM and was considered indirect evidence of the efficacy of CGM in
this population.20

A before-after monocentric 12-week pilot study21 addressed the contribution of
iterative sequences of CGM on glucose control in dialysis patients with
diabetes (n=15). The study included two 6-week periods: during the first
period, patients were asked to perform 3-6 SMBG per day with their own
glucometer device (SMBG period). During the second 6-week period, a 5-day
blinded CGM was performed at 2-week intervals using the iPro21 CGM (Medtronic)
(CGM period). Among the 15 patients, 2 had T1DM (13.3%), 9 had T2DM (60%) and
4 had secondary diabetes (26.7%). Treatments were diet alone (20%) or diet
plus insulin (80%). Mean CGM glucose level was 8.3  2.5 mmol/l at baseline,
8.2  1.6 mmol/l at the end of the SMBG period and 7.7  1.6 mmol/l at the end
of the CGM period ( _p_ < 0.05 compared to baseline). Only the mean CGM
glucose level decrease remained significant after exclusion of patients on
diet alone in a subgroup analysis (baseline: 8.8 2.5 mmol/l; at the end of
the SMBG period: 8.1  1.5 mmol/l; _p_ < 0.05; n = 12). The authors concluded
that in patients with diabetes on chronic dialysis, iterative CGM was
associated with more frequent treatment changes and better glucose control
without increased risk of hypoglycemia. The study has several limitations
including the small and heterogenous sample size, short duration of the study,
and use of a professional CGM as opposed to a personal CGM. Additionally, the
before-after study design lacked statistical power and had the potential risk
of a "carry-over" effect of SMBG on CGM use.

The Kidney Disease Improving Global Outcomes (KDIGO) Clinical Practice
Guidelines for Diabetes Management 202022 state that daily glycemic monitoring
with CGM or SMBG may help prevent hypoglycemia and improve glycemic control
when antihyperglycemic therapies associated with risk of hypoglycemia are
used.

**CGM for pregnant beneficiaries including those with gestational diabetes
mellitus (GDM)**

Non-adjunctive CGMs are not indicated for use during pregnancy based on the
FDA labeling.23,24 Adjunctive CGMs may be used during pregnancy based on the
FDA labeling.25 However, the only adjunctive CGM on the US market does not
have a standalone CGM receiver and therefore is only classified as DME when an
insulin infusion pump is used to display glucose values. Coverage of a CGM
integrated into an insulin infusion pump requires that both the coverage
criteria for a CGM and an insulin infusion pump are met. Beneficiaries
qualifying for an insulin infusion pump would likely meet the current coverage
criteria for a CGM and therefore no additional literature analysis was
conducted on this topic.

American Association of Clinical Endocrinology (AACE) Clinical Practice
Guideline on the use of Advanced Technology in the Management of Persons with
Diabetes Mellitus for 202115 recommends CGM for pregnant women with T1D and
T2D treated with intensive insulin therapy (Grade A; Intermediate-High
Strength of Evidence; BEL 1) and women with gestational diabetes mellitus(GDM)
on insulin therapy (Grade A; Intermediate Strength of Evidence; BEL 1).
Additionally, the guidelines state that CGM may be recommended for women with
GDM who are not on insulin therapy. (Grade B; Intermediate Strength of
Evidence; BEL 1).15

**CGM for other rare causes of hypoglycemia**

Beneficiaries with a confirmed diagnosis of diabetes mellitus secondary to
pancreatectomy or bariatric surgery may be eligible for coverage of a CGM if
the coverage criteria outlined in the LCD are met. The Glucose Monitors
National Coverage Determination (NCD) 40.2 limits the coverage of home blood
glucose monitors to patients diagnosed with diabetes. Therefore, patients
prescribed a CGM due to bariatric surgery or other rare causes of hypoglycemia
without a confirmed diagnosis of diabetes would not qualify under the NCD.

**Requirement for an in-person treating practitioner visit every 6 months to
assess adherence and allowance for telehealth visits**

A cross-sectional survey26 examined the relationship between primary care
physician visit frequency and nights spent in the hospital for a group of
Canadian insulin treated T2DM patients (n=2,203). The authors concluded that
insulin-dependent T2DM patients who visit general practitioners (GPs) more
frequently spend less time in-hospital than those who do not visit their GPs,
after adjusting for confounders. Additionally, a large retrospective cohort
study (n=26,496) conducted by Morrison et al. 201127 assessed the relationship
between frequent patient-provider visits and diabetic patient health outcomes.
The authors concluded that increased primary care provider encounters are
associated with faster achievement of targets for HbA1c, blood pressure, and
LDL for patients with diabetes.

The 2022 ADA Standards of Care13 recommend that glycemic status (HbA1c or
other glycemic measurement such as time in range or glucose management
indicator) be assessed at least two times a year in patients who are meeting
treatment goals (and who have stable glycemic control) and at least quarterly
in patients whose therapy has recently changed or who are not meeting their
glycemic goals. The 2018 Joslin Clinical Oversight Committee Clinical Practice
Guidelines28 recommend monitoring diabetic patient progress through medical
visits at least 2 to 4 times/year. Additionally, the guidelines state that
intensive diabetes education and support are essential for optimal CGM
implementation and monitoring.28 The CDC Diabetes Care Schedule29 recommends
patients with diabetes visit their physician every 3 months if not meeting
their treatment goals and every 6 months when they are meeting their treatment
goals.

The in-person treating practitioner visits specified in the coverage criteria
may be conducted via CMS-approved telehealth visits; therefore, no additional
research on this topic was necessary.

**Allowance for CGM supplies to be billed in 90-day increments**

The requirement for CGM supplies to be billed as a monthly allowance is a
billing and payment rule established by CMS and not within the purview of the
DME MACs.

**Health Disparities & Health Equity Assessment**

Despite diabetes mellitus being more prevalent in non-Asian ethnic minorities
and rural Americans, diabetic technology such as CGMs is less accessible to
them.30,31 In 2011, the Centers for Disease Control (CDC) identified a
644-county area of the U.S. where the incidence of DM was statistically higher
in prevalence (11.7%) than that of the rest of the country (8.5%). More than a
third of the 'diabetes belt' counties are in central and southern Appalachia,
much of which is rural.32 There are notable differences in provider access,
transportation barriers, financial challenges, housing, and food
security/access amongst particularly vulnerable diabetic patient populations,
including Native Americans, Alaskan Natives, and African Americans.33-35

A study commissioned by the ADA to determine whether access to CGMs is a
health disparity issue, found that young people are more likely to manage
their diabetes using CGMs than older Americans and that Americans of African
descent on fee-for-service Medicare or Medicare Advantage have
disproportionately lower CGM utilization rates.31 Additionally, a significant
portion of patients with diabetes do not receive their diabetes care from an
endocrinologist which likely contributes to this disparity.36,37 In surveys of
patients in vulnerable communities, two of the most frequently cited
hindrances to diabetes technology such as CGMs are at the provider level
(provider doesn't prescribe) and affordability due to lack of insurance
coverage.38-42 Health care policy requirements for in-person, face-to-face
office visits may further potentiate health disparities among rural and urban
non-Asian ethnic minorities for various reasons including, but not limited to,
expense, lack of transportation, and health-professional shortages.33-36

Based on the available evidence, a patient-centered multidisciplined approach
may be necessary to improve health equity in diabetes management. Studies
examining the impact of interventions designed to overcome social determinants
of health (e.g., access, affordability, transportation, literacy, environment,
quality of care) consistently demonstrate improvement in the outcomes of
diabetic patients.38,43 Affordability is almost universally cited as a barrier
to accessing diabetic technology.42 Disparate coverage policies can contribute
to the health disparities of diabetic technology adoption. Therefore, in light
of the high prevalence of fee-for-service Medicare and Medicare Advantage
insurance among diabetic patients, the expansion of Medicare coverage policies
for CGMs in this revised policy may help improve access for some of the most
underserved Medicare-eligible populations.31,36,38