Dr. Marilyn Tan, MD is a board-registered Endocrinology specialist in Stanford, CA (NPI #1770899395) with 29+ years of clinical experience caring for 429 Medicare beneficiaries per year (2,277 annual clinical procedures) and holding a 4.5 ★ GreatDoc™ Rating.
dotMD.com is an independent physician transparency platform engineered by the dotMD Clinical Systems Architecture Team (`audit@dotmd.com`). Physicians cannot pay to alter their GreatDoc™ Score, hide negative patient reviews, or boost placement:
The Proprietary DotMD™ J3 Model awards Dr. Marilyn Tan, MD a 4.5 ★ GreatDoc™ Rating (88/100) based on a 4.7 ★ patient review profile (23 reviews), 44th-percentile CA CMS clinical volume (429 Medicare beneficiaries/yr), and 4.7/5.0 bedside communication.
Click your carrier below to check Original Medicare Part B, Commercial PPOs, HMO/IPA referral rules, and CPT 99204 superbill verification—with zero sign-up wall:
Seeded with our independent DotMD Clinical & CMS Volume Audit (4.5 ★) and updated live by real patients in Stanford, CA.
The Proprietary DotMD™ J3 Model awards Dr. Marilyn Tan, MD a 4.5 ★ GreatDoc™ Rating (88/100) based on a 4.7 ★ patient review profile (23 reviews), 44th-percentile CA CMS clinical volume (429 Medicare beneficiaries/yr), and 4.7/5.0 bedside communication.
Check your carrier and plan type below—we separate Original Medicare Part B, Commercial Employer PPOs, and HMO/IPA Referral Plans so you never get surprised at check-in.
Participating Provider—accepts Medicare-approved assignment + Medigap (Plan G / N / F).
Anthem Blue Cross, Blue Shield, Aetna, Cigna & UnitedHealthcare PPOs (no PCP referral required).
Advantage PPOs work directly; HMO plans require prior authorization from your contracted Medical Group (IPA).
Ask the billing desk for their direct prompt-pay rate and request an itemized CPT 99204 superbill for out-of-network PPO reimbursement.
Federal CMS Part B records verify NPI #1770899395 treats 429 Medicare beneficiaries/yr and accepts Medicare-approved allowable fees (80% Medicare + 20% Medigap after annual Part B deductible).
Employer and individual PPO plans are widely accepted. Avoid confusing Anthem PPO with Anthem Pathway EPO or Medi-Cal Managed Care HMO, which restrict out-of-group specialists.
If you have Blue Shield Trio HMO or Access+ HMO, you must first obtain an authorized specialist referral from your assigned Primary Care Medical Group (IPA).
Confirm your specific employer group network ID on the back of your Aetna card when scheduling.
UHC Medicare Advantage HMO (AARP) plans require your primary care medical group to match the specialist’s contracted IPA; UHC PPO plans allow direct self-referral.
No primary care referral is required for Cigna Open Access Plus (OAP) or PPO plans.
Unlike Original Medicare Part B (where you can see any participating specialist nationwide), Medicare Advantage HMOs lock you to a specific Medical Group (IPA). Ask the front desk if they are contracted with your specific IPA before booking.
Closed-panel HMOs (like Kaiser Permanente) and narrow-network EPO/Medi-Cal plans generally do not cover independent Beverly Hills private-practice specialists unless you pay cash or obtain a formal gap-exception authorization.
“Hi, I’m scheduling a new consultation with Dr. Marilyn Tan (NPI #1770899395). Can you confirm that your practice tax ID is in-network with my specific [Carrier Name & Plan Tier] for CPT 99204 (New-Patient Specialist Consult) and CPT 99214 (Established Follow-Up Visit), and let me know if any annual administrative fee applies?”
Clinicians interrupt patients after a median of 11 seconds (J Gen Intern Med, PMID 29972200). Select your appointment reason below to generate your 1-page script:
"I have two specific goals for our 15 minutes today: first, my morning TSH is [X] mIU/L with persistent fatigue and cold intolerance, so I would like to evaluate Free T4, Free T3, TPO Antibodies, and Ferritin together; second, if we palpate any thyroid asymmetry, can we perform an in-office neck ultrasound (CPT 76536)?"
Confirms the endocrinologist images thyroid nodules themselves rather than sending you to a hospital radiology department.
Identifies structural thyroid specialists vs. general diabetes-only clinics.
Hold all Biotin (Vitamin B7) supplements for 72 hours before your blood draw so streptavidin assay interference does not create a false TSH/Free T4 reading.
"My recent HbA1c came back at [X]%. Today I want to check my Fasting Insulin to calculate HOMA-IR, discuss starting Extended-Release Metformin ER ($5.40/mo cash) or a 14-day Continuous Glucose Monitor trial (CPT 95251), and establish a 90-day re-test target below 5.4%."
Verifies the clinic actively prescribes and interprets Dexcom/Libre CGM sensor data.
Standard outpatient evaluation code; ask for transparent self-pay rates ($120–$180) if uninsured.
Bring a 3-day log of post-dinner fingerstick or CGM readings and confirm whether your pharmacy filled Metformin ER (Extended-Release) rather than immediate-release.
"My 7-day rested home blood pressure averages [X/Y] mmHg and my LDL-C is [Z] mg/dL. Today I would like to review my home cuff log against office white-coat readings, order direct Apolipoprotein B (ApoB) and one-time genetic Lipoprotein(a), and decide if a CAC score or low-dose statin/ARB is warranted."
Assesses left ventricular wall thickness and valve function directly in the cardiology suite.
Baseline rhythm and conduction screen prior to antihypertensive titration.
Bring your physical home upper-arm BP cuff to the clinic to validate calibration, along with a 7-day written morning/evening seated average.
"Even though my hemoglobin is normal, my Serum Ferritin is [X] ng/mL and I am experiencing persistent fatigue and hair shedding. Can we check a fasting Iron Panel with Transferrin Saturation (TSAT), rule out celiac/GI malabsorption, and target a Ferritin above 50–75 ng/mL?"
Confirms the hematology clinic can administer IV iron when oral iron fails or causes GI distress.
Tracks mean corpuscular volume (MCV) and early reticulocyte hemoglobin response.
Stop oral iron supplements for 24 hours before drawing a fasting morning Serum Iron and TSAT panel so circulating pill iron does not skew saturation.
"I have had [reflux / bloating / unexplained low ferritin] for [X] months. Today I want to distinguish upper GI mucosal issues from functional motility, review a step-down plan so I am not stuck on a PPI indefinitely, and verify whether you perform diagnostic EGD (CPT 43239) or colonoscopy (CPT 45385) at an ambulatory center."
High annual CPT 45385 volume (>300/yr) correlates with higher adenoma detection rates and safer polypectomy.
Rules out Barrett esophagus, H. pylori gastritis, and duodenal celiac villous atrophy.
Always request an Ambulatory Surgery Center (ASC) facility quote rather than a hospital outpatient department (HOPD) for endoscopy/colonoscopy to save $1,200–$2,400 in facility fees.
Instead of relying on self-reported marketing checklists, dotMD audits the actual CPT and HCPCS procedure codes billed by Dr. Tan to the Centers for Medicare & Medicaid Services (CMS)—translating each billing code into what happens in the exam room:
NPI #1770899395 • CBSA Regional • Endocrinology
| HCPCS | Clinical Procedure Description | Annual Volume | Local Pct |
|---|---|---|---|
| 99214 | Complex Endocrine, Thyroid & Metabolic Biomarker Management | 1,002 | 50th |
| 95251 | Ambulatory Continuous Glucose Monitoring (CGM) Data Analysis | 501 | 45th |
| 76536 | High-Resolution Thyroid & Parathyroid Neck Ultrasound | 364 | 54th |
| 99204 | Comprehensive New Patient Endocrine & Hormone Workup | 273 | 55th |
| 99215 | High-Complexity Multi-Hormone & Insulin Pump Titration | 137 | 54th |
Among 5 tracked CMS fee-schedule codes for Dr. Tan (averaging 5.3 services per beneficiary), 99214 (Complex Endocrine, Thyroid & Metabolic Biomarker Management) represents 44% of tracked volume (1002 encounters), paired with 95251 (501x).
Anchored in Stanford, CA 94305, Dr. Marilyn Tan, MD (NPI 1770899395, alumnus of Baylor College of Medicine (CMS DAC Verified)) logged 2,277 annual procedures (mid-cohort balanced caseload (50th Stanford percentile), 44.15th CA percentile, -0.47σ) with sub-specialty concentration in 14 Active CMS HCPCS Codes.
Compared against Stanford, CA Endocrinology peers
2,277 annual services across 429 beneficiaries
Standard deviations from CA Endocrinology mean utilization
Paste this lightweight SVG snippet onto your clinic bio page in Stanford, CA:
<a href="https://dotmd.com/doctors/marilyn-tan-md-stanford-ca-1770899395" title="Dr. Marilyn Tan, MD - Verified CMS Utilization on DotMD"><img src="https://dotmd.com/badges/npi/1770899395.svg" alt="Dr. Marilyn Tan Endocrinology Badge" width="280" height="72" /></a>
| Metric | Verified Benchmark | Source |
|---|---|---|
| Dr. Tan National Provider Identifier | NPI #1770899395 (MD) | CMS NPPES Registry (94305) |
| Dr. Tan Stanford CMS Volume Rank | 50.00th Pct (2,277 CMS svcs; Z -0.467σ) | CMS Medicare Part B (CA Endocrinology) |
| Annual Medicare Patients Treated | 429 unique Medicare beneficiaries/yr | CMS Medicare Physician & Other Practitioners (CA) |
| Statewide Specialty Volume Percentile | 44.15th Percentile in CA | CMS CA Endocrinology Peer Distribution |
Plain-English diagnostic cutoffs, 3-zone lab translators, and evidence-graded treatment roadmaps for conditions commonly evaluated in Endocrinology.
Compare real pharmacy acquisition invoices (CMS NADAC) against retail cash prices, meal-timing rules, and organ safety thresholds.
Audit clinical trial Absolute Risk Reduction (ARR & NNT) and TrueDose™ elemental supplement label math before your visit.
NPI #1770899395 • Active Medicare Part B & Commercial PPO Specialist • Confirm your plan tier and any annual administrative fee when booking.
Sequenced by what you need most before booking: (1) Conditions & In-Office Procedures, (2) Medicare, Insurance & Upfront Billing Rules, (3) Day-1 Lab Checklist, Parking & Wait Times, and (4) Credentials, Hospital Affiliations & Local Peer Benchmarks.
Federal CMS Medicare Part B records show Dr. Tan treats 429 unique Medicare beneficiaries and performs 2,277 clinical services per year—ranking in the 44th percentile across CA [1][2].
Annual CMS Part B utilization data tracks every office consultation (CPT 99204/99214), diagnostic evaluation, and therapeutic procedure billed for Medicare beneficiaries at 300 Pasteur DR, Stanford, CA 94305. Maintaining a 44th-percentile statewide volume means Dr. Tan's clinic manages high-complexity Endocrinology cases every week rather than occasional referrals [1][2].
Call the clinic front desk ahead of your visit to confirm whether specific diagnostic procedures are performed in-office or referred to an affiliated hospital center.
Dr. Tan is registered in the federal CMS NPPES & PECOS system under NPI #1770899395 in Stanford, CA, actively treating 429 Medicare Part B beneficiaries per year [1][2].
Original Medicare Part B covers 80% of the Medicare-approved amount for participating Endocrinology specialist visits (CPT 99204/99214) after your annual Part B deductible is met, with Medigap supplemental policies typically covering the remaining 20% coinsurance [2].
Before your appointment at 300 Pasteur DR, confirm that your specific commercial PPO/HMO plan tier or Medicare Advantage network is active with the practice billing tax ID, or ask the billing desk for their direct prompt-pay rate and an itemized CPT 99204 superbill [1][2].
Give the reception desk Dr. Tan's 10-digit NPI (#1770899395) when calling your insurer's Member Services line to verify in-network tier status in 60 seconds.
The Proprietary DotMD™ J3 Model awards Dr. Marilyn Tan, MD a 4.5 ★ GreatDoc™ Rating (88/100) based on a 4.7 ★ patient review profile (23 reviews), 44th-percentile CA CMS clinical volume (429 Medicare beneficiaries/yr), and 4.7/5.0 bedside communication.
The Proprietary DotMD™ J3 Model evaluates practicing U.S. specialists across three independent, non-sponsored pillars: 45% public Google review sentiment (4.7 ★ across 23 reviews), 35% federal CMS Medicare Part B procedure volume (44th percentile in CA), and 20% bedside communication and credential longevity [1][2][3].
Unlike commercial physician directories where doctors can pay for "Featured" placement, every GreatDoc™ Score on dotMD is calculated directly from federal CMS utilization records (NPI #1770899395) and verified patient feedback.
Always check both a specialist's patient review sentiment and their annual CMS procedure volume so you know they actively manage your condition every week.
Bring your last 12 months of sequential blood work (not just a single summary page), prior diagnostic imaging or procedure reports on PDF, and a list of your exact current medications and supplements with doses [3][4].
Because a new-patient Endocrinology consultation (CPT 99204/99205) focuses on longitudinal trends rather than isolated snapshots, having 2–3 prior lab panels side-by-side prevents duplicate blood draws and allows Dr. Tan to establish a treatment plan on Day 1.
Write down your top 3 symptom priorities in chronological order (when the symptom started, what makes it better or worse, and which medications you have already tried) and hand that sheet to the nurse during rooming so your 15-minute window stays focused.
Take clear smartphone photos of the front and back Supplement Facts panels of every vitamin you take—hidden ingredients like high-dose biotin can skew immunoassay lab tests.
Before leaving the exam room at 300 Pasteur DR, ask Dr. Tan whether a generic first-line option exists and check its federal CMS NADAC wholesale acquisition cost on dotMD [4].
Retail chain pharmacies routinely mark up 3-cent generic maintenance tablets (such as blood pressure, cholesterol, or acid-reflux medications) to $40–$60 cash per month. Asking Dr. Tan to send 90-day generic maintenance prescriptions to transparent cost-plus pharmacies or checking your insurer's Tier 1 preferred list prevents pharmacy counter sticker shock [4].
If a brand-name therapy requires Prior Authorization (PA), ask the clinic's medical assistant which step-therapy labs or prior generic trials must be documented in the chart note before you leave.
Dr. Tan practices at 300 Pasteur DR, Stanford, CA 94305. Arrive 15 minutes early for new-patient intake and insurance verification [1].
Before leaving the checkout desk, confirm two logistics: (1) whether follow-up lab orders should be drawn fasting in the morning, and (2) whether Dr. Tan reviews incoming lab results via the patient portal or requires a scheduled follow-up visit (CPT 99213/99214).
Save the clinic phone number in your phone contacts and confirm the exact suite number and parking instructions when the office calls to confirm your appointment.
Verifies active Type 1 Individual NPI #1770899395, primary taxonomy (Endocrinology), and practice location at 300 Pasteur DR, Stanford, CA 94305.
Primary federal claims ledger recording 429 annual Medicare beneficiaries and 2,277 billed HCPCS/CPT services (44.15th CA percentile).
Confirms federal Medicare Part B participation status and E&M consultation billing standards (CPT 99204/99214).
Federal wholesale pharmacy acquisition benchmark used to audit generic vs. brand prescription costs ordered during specialist consultations.
dotMD builds baseline profiles from public federal CMS Medicare and NPPES records plus public patient reviews. Claim your profile at zero cost to add your headshot, personal philosophy of care, accepted insurance plans, telehealth availability, online booking link, and official responses to patient questions.
Share your real-world consultation experience, lobby wait time, bedside manner rating, or insurance/billing tips with other patients in Stanford, CA.
Filter Dr. Marilyn Tan community Q&As, structured “What Worked For Me” reports, and dosage logs by age, sex, and duration.
