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MICHELLE SIT MD
NPI 1740269513
Internal Medicine - Rheumatology in Vacaville, CA

Active since January 11, 2006PECOS EnrolledAccepts Medicare Assignment
1010 NUT TREE RD STE 100A, VACAVILLE, CA 95687(707) 624-8532(707) 624-8501 Get Directions Write a Review

NPPES record last updated: January 7, 2026. Verified against the NPPES registry weekly; last sync: October 25, 2026.

Record update history: Jan 7, 2026, Aug 27, 2019, May 29, 2019 (3 updates tracked since 2019).

About Michelle Sit Md NPPES

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

MICHELLE SIT MD (NPI 1740269513) is an individual rheumatology provider in Vacaville, California, licensed in Virginia (0101238150) and active in the NPI registry since January 2006. She is enrolled in Medicare PECOS and is a graduate of Other (2003).

NPPES Registry Identity

NPI1740269513
Entity TypeIndividualFemale
Primary Taxonomy207RR0500X
Provider Legal NameMICHELLE SITCredential: MD
Location Address1010 NUT TREE RD STE 100AVacaville, CA 95687-4172
Mailing Address1010 Nut Tree Rd Ste 100aVacaville, CA 95687-4172 · (707) 624-8530 · Fax (707) 624-8501
Phone(707) 624-8532
Fax(707) 624-8501
Sole ProprietorNo
Medical School CMSOtherGraduated 2003
Enumeration DateJanuary 11, 2006
Last NPPES UpdateJanuary 7, 20263 updates tracked since enumeration
NPPES CertifiedJanuary 7, 2026
✔ NPI 1740269513 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyInternal Medicine · RheumatologyAllopathic & Osteopathic Physicians
Taxonomy Code207RR0500X
Licenses✔ Licensed in VA · 0101238150✔ Licensed in CA · C-188321
Definition
An internist who treats diseases of joints, muscle, bones and tendons. This specialist diagnoses and treats arthritis, back pain, muscle strains, common athletic injuries and collagen diseases.
Also ListedInternal MedicineTaxonomy 207R00000X · License 0101238150 (VA)
1010 NUT TREE RD STE 100A, Vacaville, CA 95687
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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

Michelle Sit 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 ID9537316443
PECOS Enrollment IDI20240521003564
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 Reassignments

2

Medicare enrollment records show Michelle Sit reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Northbay Healthcare Group
Same address
Multi-Specialty
1020 NUT TREE RD # 390
Vacaville, CA 95687
  • Reassigned Medicare billing, California enrollment
  • Medicare enrollment name: Northbay Physicians Surgery Center, LLC
  • 516 clinicians in this Medicare group
NPI 1760534713 (707) 624-8000
Northbay Health Medical Foundation
13 mi
Internal Medicine
4500 BUSINESS CENTER DR
Fairfield, CA 94534
  • Reassigned Medicare billing, California enrollment
  • 225 clinicians in this Medicare group
NPI 1760283527 (707) 646-3110

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 5

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.

New patient office or other outpatient visit with a high level of medical decision making, if using time, 60 minutes or more 99205
This is a first-time patient visit where a healthcare professional spends 60-74 minutes with you. It involves a comprehensive evaluation, including your medical history and current health condition. They'll also advise on preventive health measures and formulate a treatment plan if needed.
42 services42 patients
Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more 99215
This service involves a follow-up appointment for existing patients, lasting between 40 to 54 minutes. During this time, your healthcare provider will assess your current health status, discuss any changes or concerns, review your treatment plan, and answer any questions you may have.
38 services30 patients
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.
33 services24 patients
New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more 99204
This is a first-time office or outpatient visit lasting between 45-59 minutes. The healthcare provider evaluates your health, discusses your medical history, and may suggest further tests or treatments. It's an opportunity to ask questions and understand your health better.
20 services20 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.
12 services12 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 95687 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
$145.83 typical visit price
range $65.02 – $191.95
Typical copayment $36.45 (range $16.25 – $47.98)
Most-billed visit code 99204
Established Patient
$113.05 typical visit price
range $21.86 – $157.69
Typical copayment $28.26 (range $5.46 – $39.42)
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.

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 Michelle Sit's NPI number?

The NPI number for Michelle Sit is 1740269513. It was assigned to this individual provider in the NPPES registry on January 11, 2006.

Where is Michelle Sit located?

Michelle Sit practices at 1010 Nut Tree Rd Ste 100A, Vacaville, CA 95687. The listed phone number is (707) 624-8532.

What is Michelle Sit's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Rheumatology, with taxonomy code 207RR0500X.

Is Michelle Sit enrolled in Medicare?

Yes. Michelle Sit 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 organizations bill Medicare for Michelle Sit's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Michelle Sit reassigns Medicare benefits to 2 organizations: Northbay Healthcare Group (Vacaville, CA) and Northbay Health Medical Foundation (Fairfield, CA). Each 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 Michelle Sit's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

When was this NPI record last updated?

The NPPES record for Michelle Sit was last updated on January 7, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 9 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.