HOWARD GUAN M.D.
NPI 1134427636
Ophthalmology - Glaucoma Specialist in San Marcos, CA

Q: What is Howard Guan's NPI number?

The NPI number for Howard Guan is 1134427636. It was assigned to this individual provider in the NPPES registry on March 7, 2011.

Q: What is Howard Guan's specialty?

The primary specialty registered for this NPI is Ophthalmology, specializing in Glaucoma Specialist, with taxonomy code 207WX0009X.

Q: When was this NPI record last updated?

The NPPES record for Howard Guan was last updated on October 21, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 12 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 March 07, 2011PECOS EnrolledAccepts Medicare Assignment

95.02/100

CMS Quality Rating

340 RANCHEROS DRIVE, SUITES 164/166, SAN MARCOS, CA 92069(760) 598-0400(760) 290-7044 Get Directions Write a Review

NPPES record last updated: October 21, 2025. Verified against the NPPES registry weekly; last sync: November 01, 2026.

Record update history: Mar 6, 2018, Jan 27, 2016 (2 updates tracked since 2016).

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About Howard Guan M.d. NPPES

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

HOWARD GUAN M.D. (NPI 1134427636) is an individual glaucoma specialist in San Marcos, California, licensed in California (A119766) and active in the NPI registry since March 2011. He is enrolled in Medicare PECOS and is a graduate of Loma Linda University School Of Medicine (2010).

NPPES Registry Identity

NPI1134427636

Entity TypeIndividualMale

Primary Taxonomy207WX0009X

Provider Legal NameHOWARD GUANCredential: M.D.

Location Address340 RANCHEROS DRIVE, SUITES 164/166San Marcos, CA 92069

Mailing Address340 Rancheros Drive, Suites 164/166San Marcos, CA 92069 · (760) 598-0400 · Fax (760) 290-7044

Phone(760) 598-0400

Fax(760) 290-7044

Sole ProprietorNo

Medical School CMSLoma Linda University School Of MedicineGraduated 2010

Enumeration DateMarch 7, 2011

Last NPPES UpdateOctober 21, 20252 updates tracked since enumeration

NPPES CertifiedOctober 21, 2025

✔ NPI 1134427636 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyOphthalmology · Glaucoma SpecialistAllopathic & Osteopathic Physicians

Taxonomy Code207WX0009X

License✔ Licensed in CA · A119766

Definition

An ophthalmologist who specializes in the treatment of glaucoma and other disorders related to increased intraocular pressure and optic nerve damage. This specialty involves the medical and surgical treatment of these conditions.

Also ListedOphthalmologyTaxonomy 207W00000X · License A119766 (CA)

340 RANCHEROS DRIVE, San Marcos, CA 92069

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Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Anthem Blue Cross and Blue Shield, Providence Health Plan.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

Howard Guan M.d. 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 ID4385868256

PECOS Enrollment IDI20150724011344

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 Howard Guan reassigns Medicare billing to 4 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Rsf Ophthalmology, PC

Same address

Ophthalmology

340 RANCHEROS DRIVE, SUITES 164/166
San Marcos, CA 92069

Reassigned Medicare billing, California enrollment
4 clinicians in this Medicare group

NPI 1497466767 (760) 598-0400

Tory Prestera MD Inc.

Same address

Ophthalmology

340 RANCHEROS DRIVE, SUITES 164/166
San Marcos, CA 92069

Reassigned Medicare billing, California enrollment
5 clinicians in this Medicare group

NPI 1073970687 (760) 598-0400

Emergency And Acute Care Medical Corporation

23 mi

Emergency Medicine

7901 FROST ST
San Diego, CA 92123

Reassigned Medicare billing, California enrollment
1,437 clinicians in this Medicare group

NPI 1437103942 (858) 939-3400

Faculty Physicians And Surgeons Of Llusm

24 mi

Vascular Surgery

44274 GEORGE CUSHMAN CT STE 208
Temecula, CA 92592

Reassigned Medicare billing, California enrollment
2,584 clinicians in this Medicare group

NPI 1891960415 (909) 558-2822

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 16

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.

Injection, faricimab-svoa, 0.1 mg J2777

Faricimab-svoa is a medication given through an injection into the eye to treat certain eye conditions. The 0.1 mg dosage helps control disease progression, improving vision and eye health. The procedure is done by a healthcare professional.

3,900 services18 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.

370 services247 patients

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.

273 services124 patients

Photography of the retina 92250

Photography of the retina, also known as retinal imaging, is a non-invasive procedure that captures images of the back of your eye. This helps doctors identify and monitor conditions like glaucoma, macular degeneration, or diabetic retinopathy. It's painless and quick, often part of a routine eye exam.

241 services230 patients

Imaging of retina 92134

Imaging of the retina is a non-invasive procedure that captures detailed images of your eye's interior. This helps detect conditions like macular degeneration or retinal detachment. It's painless and takes only a few minutes.

225 services138 patients

Imaging of optic nerve 92133

Imaging of the optic nerve is a non-invasive procedure that captures detailed pictures of your optic nerve. It helps doctors assess eye health, particularly for conditions like glaucoma. It's painless, quick, and uses safe technology like MRI or OCT (Optical Coherence Tomography).

165 services149 patients

Exam of visual field with extended testing 92083

An extended visual field exam is a detailed test to evaluate your peripheral (side) vision. It helps to detect any potential blind spots which may not be noticeable in daily life. These could be caused by eye diseases like glaucoma, or neurological conditions.

159 services134 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.

139 services139 patients

Closure of tear duct opening using plug 68761

Closure of the tear duct opening using a plug is a procedure to address excessive tear production. A small device is inserted into the tear duct to block it, reducing tear flow and relieving symptoms. This is a safe, reversible process, often performed in-office.

106 services58 patients

Exam of the internal drainage system of eye 92020

This is a procedure where your doctor examines the eye's internal drainage system, essential for maintaining eye pressure. They use specialized tools to check for blockages or damage that might lead to conditions like glaucoma. It's non-invasive and painless.

103 services91 patients

Ultrasound scan of cornea to determine thickness 76514

An ultrasound scan of the cornea is a non-invasive procedure that uses sound waves to measure the thickness of your cornea. This helps in diagnosing certain eye conditions and planning treatments. No discomfort or pain is typically experienced.

95 services95 patients

Injection of drug into eye 67028

An injection into the eye is a procedure where a medication is delivered directly into your eye to treat various conditions. A local anesthetic is applied to numb the eye, ensuring minimal discomfort. The drug helps manage diseases like macular degeneration or diabetic retinopathy.

84 services26 patients

Measurement of corneal curvature and depth of eye 92136

This procedure measures the shape and depth of your eye, specifically the cornea, the clear front surface. It helps in diagnosing conditions, planning for surgeries, or fitting contact lenses. It's non-invasive and painless.

51 services40 patients

Removal of cataract with insertion of prosthetic lens 66984

This is a procedure where a cloudy lens in your eye, known as a cataract, is removed. After removal, a clear artificial lens is inserted. This helps to restore your vision, enabling you to see clearly again.

38 services30 patients

Laser repair to improve eye fluid flow 65855

Laser repair to improve eye fluid flow is a procedure aimed at treating glaucoma. A laser is used to create a small hole in the eye's drainage system, allowing fluid to flow out more easily. This helps to lower the pressure inside the eye, reducing the risk of vision loss.

26 services16 patients

Ct scan of cornea 92025

A CT scan of the cornea is a non-invasive imaging test that uses X-rays to capture detailed pictures of your eye's cornea. It helps in diagnosing diseases or damage, planning for surgery, or evaluating the results of a treatment. It's a safe and painless procedure.

11 services11 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 92069 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

$140.22 typical visit price

range $62.10 – $184.71

Typical copayment $35.05 (range $15.52 – $46.17)

Most-billed visit code 99204

Established Patient

$76.87 typical visit price

range $20.62 – $151.42

Typical copayment $19.21 (range $5.15 – $37.85)

Most-billed visit code 99213

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.

95.02/100

MIPS Final ScoreMerit-based Incentive Payment System · CMS Quality Payment Program

Scored as part of a group practice

Quality

100

Improvement Activities

Cost

54.87

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.

TORY PRESTERA MD INC.

Ophthalmology

340 RANCHEROS DRIVE, SUITES 164/166
SAN MARCOS, CA 92069

San Diego County (760) 598-0400

TORY PRESTERA MD.PHD

Ophthalmology

340 RANCHEROS DRIVE, SUITES 164/166
SAN MARCOS, CA 92069

San Diego County (760) 598-0400

RSF OPHTHALMOLOGY, PC

Ophthalmology

340 RANCHEROS DRIVE, SUITES 164/166
SAN MARCOS, CA 92069

San Diego County (760) 598-0400

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 Howard Guan's NPI number?

The NPI number for Howard Guan is 1134427636. It was assigned to this individual provider in the NPPES registry on March 7, 2011.

Where is Howard Guan located?

Howard Guan practices at 340 Rancheros Drive Suites 164/166, San Marcos, CA 92069. The listed phone number is (760) 598-0400.

What is Howard Guan's specialty?

The primary specialty registered for this NPI is Ophthalmology, specializing in Glaucoma Specialist, with taxonomy code 207WX0009X.

Is Howard Guan enrolled in Medicare?

Yes. Howard Guan 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 Howard Guan's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Howard Guan reassigns Medicare benefits to 4 organizations: Rsf Ophthalmology, PC (San Marcos, CA), Tory Prestera MD Inc. (San Marcos, CA), Emergency And Acute Care Medical Corporation (San Diego, CA) and Faculty Physicians And Surgeons Of Llusm (Temecula, 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 Howard Guan's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Howard Guan accept?

Health plans from Anthem Blue Cross and Blue Shield and Providence Health Plan list Howard Guan 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 Howard Guan was last updated on October 21, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 12 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.