1. Home
  2. Directory
  3. NPI Profile

MATTHEW THOMAS MIDDENDORF MD
NPI 1629305784
Internal Medicine in Agana Heights, GU

Active since November 11, 2009PECOS EnrolledAccepts Medicare Assignment
88.06/100
CMS Quality Rating
FARENHOLT AVE. BLDG. 50, AGANA HEIGHTS, GU 96910(671) 344-9340 Get Directions Write a Review

NPPES record last updated: October 1, 2025. Verified against the NPPES registry weekly; last sync: August 16, 2026.

About Matthew Thomas Middendorf Md NPPES

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

MATTHEW THOMAS MIDDENDORF MD (NPI 1629305784) is an individual internal medicine provider in Agana Heights, Guam, licensed in South Carolina (MD39270) and active in the NPI registry since November 2009. He is enrolled in Medicare PECOS, is affiliated with Guam Regional Medical City, and is a graduate of Mercer University School Of Medicine (2013).

NPPES Registry Identity

NPI1629305784
Entity TypeIndividualMale
Primary Taxonomy207R00000X
Provider Legal NameMATTHEW THOMAS MIDDENDORFCredential: MD
Location AddressFARENHOLT AVE. BLDG. 50Agana Heights, GU 96910
Mailing AddressPsc 455 Box 208Fpo, AP 96540-0003 · (706) 296-3552
Phone(671) 344-9340
Sole ProprietorYes
Medical School CMSMercer University School Of MedicineGraduated 2013
Enumeration DateNovember 11, 2009
Last NPPES UpdateOctober 1, 2025
NPPES CertifiedOctober 1, 2025
✔ NPI 1629305784 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 3

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
License✔ Licensed in SC · MD39270
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 ListedInternal Medicine · Critical Care MedicineTaxonomy 207RC0200X · License M-2396 (GU), MD-P-2025-007 (GU), MD39270 (SC)
Also ListedInternal Medicine · Pulmonary DiseaseTaxonomy 207RP1001X · License M-2396 (GU), MD-P-2025-007 (GU), MD39270 (SC)

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

Matthew Thomas Middendorf 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 ID5698024750
PECOS Enrollment IDI20231020000660
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 3

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.
39 services27 patients
Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 99232
Follow-up hospital inpatient care involves daily check-ups while you're admitted in the hospital. Typically, a healthcare provider spends about 25 minutes each day reviewing your condition, adjusting treatment if needed, and answering any questions you might have.
24 services15 patients
Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes 99222
Initial hospital inpatient care is a service where a healthcare provider spends about 50 minutes per day overseeing your care while you're admitted in the hospital. This includes reviewing your health status, planning your treatment, and ensuring your safety and comfort.
12 services12 patients

Hospital Affiliations CMS Care Compare

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

Guam Regional Medical City

Acute Care Hospitals · Dededo, GU
OwnershipVoluntary non-profit - Private
CMS Certification Number650003
Location133 Route 3Dededo, GU 96929 · Guam County
Emergency services

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 96910 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
$136.68 typical visit price
range $60.53 – $180.05
Typical copayment $34.17 (range $15.13 – $45.01)
Most-billed visit code 99204
Established Patient
$105.65 typical visit price
range $20.09 – $147.56
Typical copayment $26.41 (range $5.02 – $36.89)
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.

88.06/100
MIPS Final ScoreMerit-based Incentive Payment System · CMS Quality Payment Program
Scored as part of a group practice
Quality87.23
Improvement Activities40
Cost74.73

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 Matthew Middendorf's NPI number?

The NPI number for Matthew Middendorf is 1629305784. It was assigned to this individual provider in the NPPES registry on November 11, 2009.

Where is Matthew Middendorf located?

Matthew Middendorf practices at Farenholt Ave. Bldg. 50, Agana Heights, GU 96910. The listed phone number is (671) 344-9340.

What is Matthew Middendorf's specialty?

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

Is Matthew Middendorf enrolled in Medicare?

Yes. Matthew Middendorf 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.

Is Matthew Middendorf affiliated with any hospitals?

According to CMS data, Matthew Middendorf is affiliated with Guam Regional Medical City.

When was this NPI record last updated?

The NPPES record for Matthew Middendorf was last updated on October 1, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 10 months 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.