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GREGORY J GUZLEY MD
NPI 1427020114
Internal Medicine - Hematology & Oncology in San Antonio, TX

Active since February 06, 2006PECOS EnrolledAccepts Medicare Assignment
89.44/100
CMS Quality Rating
4411 MEDICAL DR, SAN ANTONIO, TX 78229(210) 595-5300(210) 614-8740 Get Directions Write a Review

NPPES record last updated: January 28, 2016. Verified against the NPPES registry weekly; last sync: October 25, 2026.

About Gregory J Guzley Md NPPES

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

GREGORY J GUZLEY MD (NPI 1427020114) is an individual hematology & oncology provider in San Antonio, Texas, licensed in Texas (F1613) and active in the NPI registry since February 2006. He is enrolled in Medicare PECOS and is a graduate of Baylor College Of Medicine (1978).

NPPES Registry Identity

NPI1427020114
Entity TypeIndividualMale
Primary Taxonomy207RH0003X
Provider Legal NameGREGORY J GUZLEYCredential: MD
Location Address4411 MEDICAL DRSan Antonio, TX 78229-3822
Mailing AddressPo Box 911230Dallas, TX 75391-1230 · (972) 997-8000 · Fax (972) 234-2987
Phone(210) 595-5300
Fax(210) 614-8740
Sole ProprietorNo
Medical School CMSBaylor College Of MedicineGraduated 1978
Enumeration DateFebruary 6, 2006
Last NPPES UpdateJanuary 28, 2016
✔ NPI 1427020114 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · Hematology & OncologyAllopathic & Osteopathic Physicians
Taxonomy Code207RH0003X
License✔ Licensed in TX · F1613
Definition
An internist doctor of osteopathy that specializes in the treatment of the combination of hematology and oncology disorders. A doctor of osteopathy that is board eligible/certified by the American Osteopathic Board of Internal Medicine WAS able to obtain a Certificate of Special Qualifications in the field of Hematology and Oncology. The Certificate is NO longer offered.
4411 MEDICAL DR, San Antonio, TX 78229
Open in Google Maps ↗

Other Identifiers 9

Medicaid116715701TX
Medicaid116715704TX
Medicare UPINB23219TX
Medicare PIN83Z208TX
Medicare PIN437919YKYCTX
Medicare PIN830005492TX
Other83Z208TX · Bcbs
OtherP01547632TX · Railroad Medicare
Medicaid116715705TX

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Blue Cross and Blue Shield of Texas.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Gregory J Guzley 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 ID5294832952
PECOS Enrollment IDI20100127000728
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.

Medicare Billing Reassignment

Medicare enrollment records show Gregory Guzley reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Texas Oncology PA
69 mi
Medical Oncology
4101 JAMES CASEY ST STE 100
Austin, TX 78745
  • Reassigned Medicare billing, Texas enrollment
  • 1,054 clinicians in this Medicare group
NPI 1972770303 (972) 997-8000

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Areas of Expertise CMS Part B claims 7

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.

Blood test, comprehensive group of blood chemicals 80053
A comprehensive group of blood chemicals test, also known as a comprehensive metabolic panel, is a blood test that measures your sugar level, electrolyte and fluid balance, kidney function, and liver function. This helps to check your body's overall health.
33 services30 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.
32 services28 patients
Complete blood cell count (red cells, white blood cell, platelets), automated test and automated differential white blood cell count 85025
A Complete Blood Cell Count is a common test that measures various components of the blood, including red cells (carry oxygen), white cells (fight infection), and platelets (help blood clot). An automated test ensures accuracy. The differential count provides detailed information about white cell types.
32 services28 patients
Ferritin (blood protein) level 82728
A Ferritin level test measures the amount of ferritin, a protein that stores iron, in your blood. It helps determine how much iron your body is storing. If levels are low, it may indicate iron deficiency, while high levels could signify conditions like iron overload.
14 services13 patients
Iron level 83540
An iron level test measures the amount of iron in your blood. Iron is crucial for producing hemoglobin, a protein in red blood cells that carries oxygen throughout your body. This test helps identify iron deficiencies or excesses, which can lead to conditions like anemia or hemochromatosis.
14 services13 patients
Iron binding capacity 83550
Iron binding capacity is a blood test that measures how well your body can bind and transport iron. This helps your healthcare provider assess if your body has too little or too much iron, which can indicate certain health conditions.
14 services13 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 78229 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
$166.88 typical visit price
range $54.84 – $166.88
Typical copayment $41.72 (range $13.71 – $41.72)
Most-billed visit code 99205
Established Patient
$97.05 typical visit price
range $17.52 – $136.11
Typical copayment $24.26 (range $4.38 – $34.02)
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.

Medicare Quality Performance CMS QPP · MIPS

Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.

89.44/100
MIPS Final ScoreMerit-based Incentive Payment System · CMS Quality Payment Program
Scored through an Alternative Payment Model
Quality75.85
Promoting Interoperability100
Improvement Activities40

Other Providers at the Same Location NPPES 20

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

DR. ANTONIO SANTILLAN-GOMEZ M.D.
Obstetrics & Gynecology (Gynecologic Oncology)
4411 MEDICAL DR, STE. 100
SAN ANTONIO, TX 78229
Bexar County (210) 595-5300
ANANTH K PRASAD MD
Internal Medicine (Cardiovascular Disease)
4411 MEDICAL DR, STE 300
SAN ANTONIO, TX 78229
Bexar County (210) 614-5400
PAUL V CELIO MD
Internal Medicine (Cardiovascular Disease)
4411 MEDICAL DR, STE 300
SAN ANTONIO, TX 78229
Bexar County (210) 614-5400
HUNTER M ADDIS MD
Internal Medicine (Cardiovascular Disease)
4411 MEDICAL DR, STE 300
SAN ANTONIO, TX 78229
Bexar County (210) 614-5400
CARLOS A ROMAN MD
Internal Medicine (Clinical Cardiac Electrophysiology)
4411 MEDICAL DR, STE 300
SAN ANTONIO, TX 78229
Bexar County (210) 614-5400
DR. NANDISH KUMAR THUKRAL M.D.
Internal Medicine (Interventional Cardiology)
4411 MEDICAL DR, 300
SAN ANTONIO, TX 78229
Bexar County (210) 614-5400
COLLINS O IDIEGBE ACNP
Nurse Practitioner (Acute Care)
4411 MEDICAL DR, 300
SAN ANTONIO, TX 78229
Bexar County (210) 614-5400
DR. SATYA RAO M.D.
Internal Medicine (Cardiovascular Disease)
4411 MEDICAL DR, SUITE 300
SAN ANTONIO, TX 78229
Bexar County (210) 614-5400

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 Gregory Guzley's NPI number?

The NPI number for Gregory Guzley is 1427020114. It was assigned to this individual provider in the NPPES registry on February 6, 2006.

Where is Gregory Guzley located?

Gregory Guzley practices at 4411 Medical Dr, San Antonio, TX 78229. The listed phone number is (210) 595-5300.

What is Gregory Guzley's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Hematology & Oncology, with taxonomy code 207RH0003X.

Is Gregory Guzley enrolled in Medicare?

Yes. Gregory Guzley 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.

Which organization bills Medicare for Gregory Guzley's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Gregory Guzley reassigns Medicare benefits to Texas Oncology PA (Austin, TX). The reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Gregory Guzley's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Gregory Guzley accept?

Health plans from Blue Cross and Blue Shield of Texas list Gregory Guzley 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.

When was this NPI record last updated?

The NPPES record for Gregory Guzley was last updated on January 28, 2016. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 10 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.