MACKENZIE GRAYE MCMILLIN PA-C
NPI 1558923326
Physician Assistant - Surgical in Portland, ME

Active since July 02, 2019PECOS EnrolledAccepts Medicare Assignment
33 SEWALL ST, PORTLAND, ME 04102(072) 828-2100(207) 553-7166 Get Directions Write a Review

NPPES record last updated: July 21, 2026. Verified against the NPPES registry weekly; last sync: September 20, 2026.

Record update history: Jul 21, 2026, Feb 17, 2022, Sep 14, 2021 and 1 more (4 updates tracked since 2019).

About Mackenzie Graye Mcmillin Pa-c NPPES

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

MACKENZIE GRAYE MCMILLIN PA-C (NPI 1558923326) is an individual surgical provider in Portland, Maine, licensed in Maine (PA1918) and active in the NPI registry since July 2019. She is enrolled in Medicare PECOS, maintains 3 additional practice locations, and is a graduate of Other (2018).

NPPES Registry Identity

NPI1558923326
Entity TypeIndividualFemale
Primary Taxonomy363AS0400X
Provider Legal NameMACKENZIE GRAYE MCMILLINCredential: PA-C
Location Address33 SEWALL STPortland, ME 04102-2638
Mailing Address33 Sewall StPortland, ME 04102-2638 · (207) 828-2100 · Fax (207) 553-7166
Fax(207) 553-7166
Sole ProprietorNo
Medical School CMSOtherGraduated 2018
Enumeration DateJuly 2, 2019
Last NPPES UpdateJuly 21, 20264 updates tracked since enumeration
NPPES CertifiedJuly 21, 2026
NPI 1558923326 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

Primary SpecialtyPhysician Assistant · SurgicalPhysician Assistants & Advanced Practice Nursing Providers
Taxonomy Code363AS0400X
License Licensed in ME · PA1918
Also ListedPhysician AssistantTaxonomy 363A00000X · License PAN1918 (ME)
33 SEWALL ST, Portland, ME 04102

Secondary Practice Locations 3

Location 14 Commons Ave Ste AWindham, ME 04062-5554 · Phone (207) 828-2100 · Fax (207) 553-7166
Location 214 Thomas Point RdBrunswick, ME 04011-3911 · Phone (207) 828-2100 · Fax (207) 553-7166
Location 322 Station Ave Ste 201Brunswick, ME 04011-2092 · Phone (207) 828-2100 · Fax (207) 553-7166

Other Identifiers 1

Medicaid1558923326ME

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

Mackenzie Graye Mcmillin Pa-c 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 ID244567147
PECOS Enrollment IDI20190815001757
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 9

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 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.
92 services67 patients
New patient office or other outpatient visit with low level of medical decision making, if using time, 30 minutes or more 99203
This service involves an initial office or outpatient visit for a new patient. The healthcare professional will spend 30-44 minutes understanding your health history, current issues, and discussing possible treatment plans. It's a comprehensive evaluation to start your healthcare journey.
58 services58 patients
X-ray of wrist, minimum of 3 views 73110
An X-ray of the wrist, minimum of 3 views, is a diagnostic procedure that uses radiation to create images of your wrist from different angles. This helps detect fractures, infections, or other abnormalities for accurate diagnosis and treatment planning.
30 services21 patients
Injection into tendon or ligament 20550
An injection into a tendon or ligament involves placing medication directly into these areas to help reduce inflammation and pain. It's often used for conditions like arthritis or tendonitis. The procedure is quick and usually involves a local anesthetic.
23 services21 patients
X-ray of wrist, 2 views 73100
An X-ray of the wrist, 2 views, is a diagnostic procedure where two different images of your wrist are taken using a small amount of radiation. This helps identify any abnormalities or injuries such as fractures or arthritis. It's a quick, non-invasive process.
23 services13 patients
Aspiration and/or injection of fluid from large joint 20610
This procedure involves using a needle to remove (aspiration) or introduce (injection) fluid into a large joint like the knee or hip. It can help diagnose conditions, relieve discomfort, or deliver medication directly to the joint.
19 services19 patients

Referred Medical Equipment & Supplies CMS DME claims

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

Walker, folding, wheeled, adjustable or fixed height E0143
DME-Other DME · category DE000N
3 suppliers16 claims16 services$58.74 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 20

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

Specialist/Technologist (Athletic Trainer)
33 SEWALL ST
PORTLAND, ME 04102
Physician Assistant
33 SEWALL ST
PORTLAND, ME 04102
Occupational Therapist
33 SEWALL ST
PORTLAND, ME 04102
Physical Medicine & Rehabilitation
33 SEWALL ST
PORTLAND, ME 04102
Physician Assistant (Surgical)
33 SEWALL ST
PORTLAND, ME 04102
Occupational Therapist
33 SEWALL ST
PORTLAND, ME 04102
Specialist/Technologist (Athletic Trainer)
33 SEWALL ST
PORTLAND, ME 04102
Orthopaedic Surgery (Hand Surgery)
33 SEWALL ST
PORTLAND, ME 04102

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 Mackenzie Mcmillin's NPI number?

The NPI number for Mackenzie Mcmillin is 1558923326. It was assigned to this individual provider in the NPPES registry on July 2, 2019.

Where is Mackenzie Mcmillin located?

Mackenzie Mcmillin practices at 33 Sewall St, Portland, ME 04102. The listed phone number is (072) 828-2100.

What is Mackenzie Mcmillin's specialty?

The primary specialty registered for this NPI is Physician Assistant, specializing in Surgical, with taxonomy code 363AS0400X.

Is Mackenzie Mcmillin enrolled in Medicare?

Yes. Mackenzie Mcmillin 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.

When was this NPI record last updated?

The NPPES record for Mackenzie Mcmillin was last updated on July 21, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 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.