1. Home
  2. Directory
  3. Missouri
  4. Union
  5. Internal Medicine
  6. NPI Profile

DR. GRETCHEN ELIZABETH FARMER MD
NPI 1720283450
Internal Medicine in Union, MO

Active since June 21, 2007PECOS EnrolledAccepts Medicare Assignment
1935 PRAIRIE DELL RD STE 400, UNION, MO 63084(636) 649-3085(636) 649-3087 Get Directions Write a Review

NPPES record last updated: June 24, 2024. Verified against the NPPES registry weekly; last sync: August 02, 2026.

Record update history: Jun 24, 2024, Jan 24, 2023 (2 updates tracked since 2023).

About Dr. Gretchen Elizabeth Farmer Md NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. GRETCHEN ELIZABETH FARMER MD (NPI 1720283450) is an individual internal medicine provider in Union, Missouri, licensed in Missouri (2007005528) and active in the NPI registry since June 2007. She is enrolled in Medicare PECOS, is affiliated with Mercy Hospital St Louis, and is a graduate of Saint Louis University School Of Medicine (2003).

NPPES Registry Identity

NPI1720283450
Entity TypeIndividualFemale
Primary Taxonomy207R00000X
Provider Legal NameDR. GRETCHEN ELIZABETH FARMERCredential: MD
Location Address1935 PRAIRIE DELL RD STE 400Union, MO 63084-4327
Mailing Address1935 Prairie Dell Rd Ste 400Union, MO 63084-4327 · (636) 649-3085 · Fax (636) 649-3086
Phone(636) 649-3085
Fax(636) 649-3087
Sole ProprietorNo
Medical School CMSSaint Louis University School Of MedicineGraduated 2003
Enumeration DateJune 21, 2007
Last NPPES UpdateJune 24, 20242 updates tracked since enumeration
NPPES CertifiedJune 24, 2024
✔ NPI 1720283450 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
License✔ Licensed in MO · 2007005528
Definition
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
Also ListedPediatricsTaxonomy 208000000X · License 2007005528 (MO)
1935 PRAIRIE DELL RD STE 400, Union, MO 63084
Open in Google Maps ↗

Other Names 1

Former Name (1)Gretchen Elizabeth Kluesner Md

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Ambetter from Arkansas Health & Wellness, Ambetter from Home State Health, Ambetter from Sunflower Health Plan and more.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Dr. Gretchen Elizabeth Farmer Md is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID4981799475
PECOS Enrollment IDI20070928000052
Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Areas of Expertise CMS Part B claims 6

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more 99214
This is a routine check-up for patients who have previously visited our clinic. It involves a comprehensive review of your health and any ongoing treatments. The consultation lasts between 30-39 minutes, allowing enough time to discuss any concerns.
142 services69 patients
Insertion of needle into vein for collection of blood sample 36415
This procedure involves inserting a small needle into a vein, typically in your arm, to collect a blood sample. It's a quick and simple process to help diagnose or monitor health conditions. You may feel a small prick, but discomfort is minimal.
110 services66 patients
Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit G0439
An annual wellness visit is a yearly appointment with your primary care provider to create or update a personalized prevention plan. This plan helps prevent illness based on your current health and risk factors. It's a subsequent visit, meaning it follows an initial assessment.
30 services30 patients
Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more 99213
This is a routine visit for patients who have already been seen by the healthcare provider. During this approximately 20-29 minute appointment, your health status will be evaluated and any necessary treatments or tests will be discussed. It's a chance to address any health concerns you may have.
27 services23 patients
Administration of influenza virus vaccine G0008
The administration of the influenza virus vaccine, also known as the flu shot, is a simple procedure to protect against the flu. A healthcare provider injects a small dose of the vaccine into your arm. This stimulates your immune system to produce antibodies, which will help your body fight off the flu if exposed.
26 services26 patients
Influenza vaccine split virus, preservative free 90662
The Influenza Vaccine Split Virus, preservative-free, is a flu shot to protect against the influenza virus. It is made from parts of inactivated flu viruses and doesn't contain preservatives, reducing potential side effects. It helps your body develop immunity to the flu.
19 services19 patients

Hospital Affiliations CMS Care Compare 2

Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.

Mercy Hospital St Louis

Acute Care Hospitals · Saint Louis, MO
4/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number260020
Location615 New Ballas RoadSaint Louis, MO 63141 · St. Louis County
Emergency services Birthing friendly

Mercy Hospital Washington

Acute Care Hospitals · Washington, MO
4/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number260052
Location901 East 5th StreetWashington, MO 63090 · Franklin County
Emergency services

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 63084 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$121.96 typical visit price
range $52.28 – $161.24
Typical copayment $30.49 (range $13.07 – $40.31)
Most-billed visit code 99204
Established Patient
$93.24 typical visit price
range $16.30 – $131.05
Typical copayment $23.31 (range $4.07 – $32.76)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Referred Medical Equipment & Supplies CMS DME claims 7

Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.

Blood glucose test or reagent strips for home blood glucose monitor, per 50 strips A4253
DME-Other DME · category DE017N
4 suppliers16 claims37 services$6.49 avg. paid by Medicare
Lancets, per box of 100 A4259
DME-Medical/Surgical Supplies · category DA000N
5 suppliers11 claims14 services$1.15 avg. paid by Medicare
Oxygen concentrator, single delivery port, capable of delivering 85 percent or greater oxygen concentration at the prescribed flow rate E1390
DME-Oxygen and Supplies · category DC002N
1 supplier12 claims12 services$65.04 avg. paid by Medicare
Arformoterol, inhalation solution, fda approved final product, non-compounded, administered through dme, unit dose form, 15 micrograms J7605
DME-Drugs Administered Through DME · category DG006N
2 suppliers12 claims720 services$4.54 avg. paid by Medicare
Albuterol, inhalation solution, fda-approved final product, non-compounded, administered through dme, unit dose, 1 mg J7613
DME-Drugs Administered Through DME · category DG006N
3 suppliers13 claims2,175 services$0.03 avg. paid by Medicare
Budesonide, inhalation solution, fda-approved final product, non-compounded, administered through dme, unit dose form, up to 0.5 mg J7626
DME-Drugs Administered Through DME · category DG000N
2 suppliers12 claims720 services$0.82 avg. paid by Medicare
Dollar amounts are the average Medicare paid the supplier per service. They are not the cost to the patient.

Other Providers at the Same Location NPPES 4

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

DR. ELIZABETH P HAMMER M.D.
Pediatrics
1935 PRAIRIE DELL RD STE 400
UNION, MO 63084
Franklin County (636) 649-3085
MRS. SARAH CHALK APRN, FNP-BC
Nurse Practitioner (Family)
1935 PRAIRIE DELL RD STE 400
UNION, MO 63084
Franklin County (636) 649-3085
DR. JOI C IRVING M.D.
Internal Medicine
1935 PRAIRIE DELL RD STE 400
UNION, MO 63084
Franklin County (636) 583-2508
CASEY LYNN BUNCHER FNP-C
Nurse Practitioner (Family)
1935 PRAIRIE DELL RD STE 400
UNION, MO 63084
Franklin County (636) 649-3085

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Gretchen Farmer's NPI number?

The NPI number for Gretchen Farmer is 1720283450. It was assigned to this individual provider in the NPPES registry on June 21, 2007. The provider is also known as Gretchen Elizabeth Kluesner MD.

Where is Gretchen Farmer located?

Gretchen Farmer practices at 1935 Prairie Dell Rd Ste 400, Union, MO 63084. The listed phone number is (636) 649-3085.

What is Gretchen Farmer's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is Gretchen Farmer enrolled in Medicare?

Yes. Gretchen Farmer is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

What insurance does Gretchen Farmer accept?

Health plans from Ambetter Health, Ambetter Health of Delaware, Ambetter from Arkansas Health & Wellness, Ambetter from Home State Health and Ambetter from Sunflower Health Plan and 5 other insurers list Gretchen Farmer as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.

Is Gretchen Farmer affiliated with any hospitals?

According to CMS data, Gretchen Farmer is affiliated with Mercy Hospital St Louis and Mercy Hospital Washington.

When was this NPI record last updated?

The NPPES record for Gretchen Farmer was last updated on June 24, 2024. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.