MARK DAY DO
NPI 1164436994
Family Medicine in Las Vegas, NV

Q: What is Mark Day's NPI number?

The NPI number for Mark Day is 1164436994. It was assigned to this individual provider in the NPPES registry on July 28, 2006.

Q: What is Mark Day's specialty?

The primary specialty registered for this NPI is Family Medicine with taxonomy code 207Q00000X.

Q: When was this NPI record last updated?

The NPPES record for Mark Day was last updated on November 6, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 11 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.

Active since July 28, 2006PECOS EnrolledAccepts Medicare Assignment

1655 E CACTUS AVE STE 400, LAS VEGAS, NV 89183(702) 724-8777(702) 724-8749 Get Directions Write a Review

NPPES record last updated: November 6, 2025. Verified against the NPPES registry weekly; last sync: October 18, 2026.

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About Mark Day Do NPPES

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

MARK DAY DO (NPI 1164436994) is an individual family medicine provider in Las Vegas, Nevada, licensed in Nevada (656) and active in the NPI registry since July 2006. He is enrolled in Medicare PECOS, is affiliated with Summerlin Hospital Medical Center, and maintains a secondary practice location in Henderson.

NPPES Registry Identity

NPI1164436994

Entity TypeIndividualMale

Primary Taxonomy207Q00000X

Provider Legal NameMARK DAYCredential: DO

Location Address1655 E CACTUS AVE STE 400Las Vegas, NV 89183-7723

Mailing AddressPo Box 50698Henderson, NV 89074-0698 · (702) 456-9100 · Fax (702) 434-7354

Phone(702) 724-8777

Fax(702) 724-8749

Sole ProprietorNo

Medical School CMSDes Moines University Of Osteopathic Medicine And Health SciencesGraduated 1990

Enumeration DateJuly 28, 2006

Last NPPES UpdateNovember 6, 2025

NPPES CertifiedNovember 6, 2025

✔ NPI 1164436994 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyFamily MedicineAllopathic & Osteopathic Physicians

Taxonomy Code207Q00000X

License✔ Licensed in NV · 656

Definition

Family Medicine is the medical specialty which is concerned with the total health care of the individual and the family. It is the specialty in breadth which integrates the biological, clinical, and behavioral sciences. The scope of family medicine is not limited by age, sex, organ system, or disease entity.

1655 E CACTUS AVE STE 400, Las Vegas, NV 89183

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Secondary Practice Location 1

Location 156 N Pecos Rd, Ste AHenderson, NV 89074-0698 · Phone (702) 456-9100 · Fax (702) 434-7354

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

Mark Day Do 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 ID547386807

PECOS Enrollment IDI20100924000328

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

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

Southwest Medical Associates, Inc

11 mi

Internal Medicine

888 S RANCHO DR
Las Vegas, NV 89106

Reassigned Medicare billing, Nevada enrollment
406 clinicians in this Medicare group

NPI 1659346005 (702) 877-8600

Optum Medical Group II Rhodes P C

16 mi

Internal Medicine

2704 N TENAYA WAY
Las Vegas, NV 89128

Reassigned Medicare billing, Nevada enrollment
608 clinicians in this Medicare group

NPI 1790329407 (702) 877-5199

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.

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.

619 services322 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.

20 services19 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.

19 services18 patients

Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report 93000

An electrocardiogram (ECG) is a non-invasive test that records your heart's electrical activity. Using 12 leads attached to your body, it captures data to help identify heart conditions. A doctor interprets the results and provides a report.

17 services17 patients

Removal of deep lymph nodes of neck 38542

This procedure involves removing lymph nodes in the neck to treat or prevent disease spread. It's often related to cancer care. The surgeon makes an incision, removes the nodes, and then closes the incision. Afterwards, some discomfort and swelling may occur.

15 services15 patients

Removal or exploration of parathyroid glands 60500

The procedure for removal or exploration of parathyroid glands involves a surgeon making a small incision in the neck to locate and remove one or more of the tiny parathyroid glands. These glands control calcium levels in the body. This procedure helps treat conditions like hyperparathyroidism.

14 services14 patients

Hospital Affiliations CMS Care Compare

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

Summerlin Hospital Medical Center

Acute Care Hospitals · Las Vegas, NV

2/5 CMS rating

OwnershipProprietary

CMS Certification Number290041

Location657 Town Center DriveLas Vegas, NV 89144 · Clark County

Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 89183 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

$88.51 typical visit price

range $57.07 – $173.24

Typical copayment $22.12 (range $14.26 – $43.31)

Most-billed visit code 99203

Established Patient

$100.60 typical visit price

range $18.27 – $140.96

Typical copayment $25.15 (range $4.56 – $35.24)

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 4

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

Nasal interface (mask or cannula type) used with positive airway pressure device, with or without head strap A7034

DME-Other DME · category DE001N

4 suppliers15 claims15 services$46.42 avg. paid by Medicare

Tubing used with positive airway pressure device A7037

DME-Other DME · category DE001N

4 suppliers11 claims11 services$10.13 avg. paid by Medicare

Filter, disposable, used with positive airway pressure device A7038

DME-Other DME · category DE001N

5 suppliers12 claims72 services$1.80 avg. paid by Medicare

Standard wheelchair K0001

DME-Wheelchairs · category DD000N

1 supplier12 claims12 services$13.05 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 3

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

PAIGE CEJKA

Physician Assistant

1655 E CACTUS AVE STE 400
LAS VEGAS, NV 89183

Clark County (702) 724-8777

ERUM KARAFA PA-C

Physician Assistant

1655 E CACTUS AVE STE 400
LAS VEGAS, NV 89183

Clark County (702) 724-8777

JOOBIN PARK M.D.

Internal Medicine

1655 E CACTUS AVE STE 400
LAS VEGAS, NV 89183

Clark County (702) 724-8777

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 Mark Day's NPI number?

The NPI number for Mark Day is 1164436994. It was assigned to this individual provider in the NPPES registry on July 28, 2006.

Where is Mark Day located?

Mark Day practices at 1655 E Cactus Ave Ste 400, Las Vegas, NV 89183. The listed phone number is (702) 724-8777.

What is Mark Day's specialty?

The primary specialty registered for this NPI is Family Medicine with taxonomy code 207Q00000X.

Is Mark Day enrolled in Medicare?

Yes. Mark Day 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 Mark Day's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Mark Day reassigns Medicare benefits to 2 organizations: Southwest Medical Associates, Inc (Las Vegas, NV) and Optum Medical Group II Rhodes P C (Las Vegas, NV). 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 Mark Day's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

Is Mark Day affiliated with any hospitals?

According to CMS data, Mark Day is affiliated with Summerlin Hospital Medical Center.

When was this NPI record last updated?

The NPPES record for Mark Day was last updated on November 6, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 11 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.