DR. SIDDHARTH TAMBAR MD
NPI 1477655488
Internal Medicine - Rheumatology in Chicago, IL

NPI Status: Active since September 01, 2006

Contact Information

618 W FULTON ST
CHICAGO, IL
ZIP 60661
Phone: (773) 348-7171
Fax: (737) 348-7414

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  • Individual
  • Male
  • Years of Experience 25
  • Internal Medicine
  • Rheumatology
  • Accepts Medicare Approved Payment
  • PECOS Enrolled
  • Medicare Quality Reporting
  • CLIA Number: 14D2183012
  • CLIA Cert. Type: Physician Office
  • CLIA Exp. Date: 04-27-2028

About SIDDHARTH TAMBAR

This page provides the complete NPI Profile along with additional information for Siddharth Tambar, an internist established in Chicago, Illinois with a medical specialization in Internal Medicine, focusing in rheumatology and more than 25 years of experience. The healthcare provider is registered in the NPI registry with number 1477655488 assigned on September 2006. The practitioner's primary taxonomy code is 207RR0500X with license number 036-111655 (IL). The provider is registered as an individual and his NPI record was last updated February 2026.

NPI
1477655488
Provider Name
DR. SIDDHARTH TAMBAR MD
Gender
Male
Entity Type
Individual
Location Address
618 W FULTON ST CHICAGO, IL 60661
Location Phone
(773) 348-7171
Location Fax
(737) 348-7414
Mailing Address
618 W FULTON ST CHICAGO, IL 60661
Mailing Phone
(773) 348-7171
Mailing Fax
(737) 348-7414
Medical School Name
OTHER
Graduation Year
2001
Is Sole Proprietor?
Yes
Enumeration Date
09-01-2006
Last Update Date
02-25-2026
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An internist like Siddharth Tambar is a physician who has completed an internal medicine residency and is board-certified or board-eligible in an internist specialty. Internists are trained to care for adults of all ages for many different medical conditions. An internist typically monitors chronic physical conditions, identifies acute diseases, provides family planning, provides counseling about wellness and disease prevention, etc.

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Specialty - Primary Taxonomy

The NPI enumerator requires providers to submit at least one taxonomy code. A taxonomy code is a unique 10-character code that describes the healthcare provider type, classification, and the area of specialization. There could be only one primary taxonomy code per NPI record. For individual NPIs the license data is associated to the taxonomy code.

Classification

Internal Medicine Rheumatology

Taxonomy Code
207RR0500X
Type
Allopathic & Osteopathic Physicians
License No.
036-111655
License State
IL
Taxonomy Description
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.

Secondary Taxonomies

The provider has reported to the NPI enumerator additional taxonomy codes. Multiple taxonomy codes may represent subspecialties or other areas of specialization the provider maybe licensed to practice.

No. Taxonomy Code Type Classification /
Specialization
License No. (State)
1207R00000XAllopathic & Osteopathic Physicians

Internal Medicine

036-111655 (IL)

Medicare Participation & PECOS Enrollment Status

Siddharth Tambar is registered with Medicare and accepts claims assignment, this means the provider accepts the approved amount for the cost of rendered services as full payment. Participating providers may not charge beneficiaries more than the approved amount for their services. Please keep in mind that beneficiaries still have to pay a coinsurance or copayment amount for a visit or service.

Siddharth Tambar is enrolled in PECOS and is eligible to order or refer health care services for Medicare patients. The provider is eligible to order or refer: Part B Clinical Laboratory and Imaging, Durable Medical Equipment (DME), a Home Health Agency (HHA) and Power Mobility Devices.

What is PECOS?
PECOS is the online Medicare enrollment management system or Provider, Enrollment, Chain and Ownership System. The PECOS system is a database of providers who have registered with CMS as providers or suppliers. PECOS is the primary source of information about verified Medicare professionals. Providers that want to participate in this program need to enroll in PECOS with their NPI number to avoid denied claims.

  • Is the provider registered in PECOS? Yes

  • PECOS PAC ID: 8325093958

    What is the PECOS Associate Control ID?
    A PAC ID is a unique 10-digit number assigned to an individual or organization healthcare provider in PECOS. The PAC ID is used to link together all the provider information, like tax identification numbers and organizational names. A PAC ID can be connected to multiple Enrollment IDs if an individual or organization has enrolled in PECOS more than once.

  • PECOS Enrollment ID: I20050316001031

    What is the Provider Enrollment ID?
    The Enrollment ID is a unique alphanumeric 15-digit code assigned to each new provider's PECOS enrollment application. The Enrollment ID is used to link together all the provider enrollment information like enrollment type, state, provider specialty, and reassignment of benefits.

  • Accepts Medicare Assignment? Yes

    What does it mean "accepts medicare assignment"?
    When a provider accepts Medicare assignment, the provider agrees to be paid directly by Medicare and to accept the payment amount approved by Medicare. Additionally, the provider agrees to not bill patients for more than the Medicare deductible and coinsurance amounts.
    A provider who doesn't accept assignment may charge you up to 15% over the Medicare-approved amount. This is known as the limiting charge. You may have to pay this amount, or it may be covered by another insurer.

  • Eligible to Order or Refer Part B Clinical Laboratory and Imaging: Yes

  • Eligible to Order or Refer Durable Medical Equipment (DMEPOS): Yes

  • Eligible to Order or Refer a Home Health Agency (HHA): Yes

  • Eligible to Order or Refer Power Mobility Devices: Yes

Areas of Expertise

The following services and procedures, recently provided to Medicare patients, illustrate the range of care this provider offers. This list reflects the variety of services available to all patients visiting the practice and is based on 2022 Medicare dataset. In general, the more frequently a provider treats specific conditions or performs particular procedures, the more experienced they become in addressing similar patient needs. The provider has delivered many of the services listed below to Medicare patients. Please note that this list does not include services provided to patients who are not covered by Medicare.

Administration of chemotherapy into vein, 1 hour or less

Chemotherapy is a treatment that uses drugs to destroy cancer cells. When administered into a vein, it's often through an IV. This procedure usually lasts 1 hour or less. You may feel a slight pinch as the needle is inserted, but it's generally painless.

This service was performed 86 times for 15 patients

Complete ultrasound scan of joint

A complete ultrasound scan of a joint is a non-invasive procedure using sound waves to create images of your joint. It helps identify problems like inflammation, injury, or disease. It's painless, safe, and doesn't involve radiation.

This service was performed 107 times for 61 patients

Established patient office or other outpatient visit, 20-29 minutes

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.

This service was performed 152 times for 69 patients

Established patient office or other outpatient visit, 30-39 minutes

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.

This service was performed 150 times for 67 patients

Injection, golimumab, 1 mg, for intravenous use

Golimumab is a medication given through an IV (a small tube in your vein). It helps to reduce inflammation and pain by blocking a protein in your body that causes inflammation. It's often used to treat conditions like rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis.

This service was performed 11,600 times for 11 patients

Injection, methylprednisolone acetate, 40 mg

Methylprednisolone acetate is a medication given through an injection. It's a type of corticosteroid, which reduces inflammation and immune responses. It can be used to treat various conditions like arthritis, allergies, and skin diseases. This dose is 40 mg.

This service was performed 13 times for 12 patients

New patient office or other outpatient visit, 45-59 minutes

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.

This service was performed 33 times for 33 patients

New patient office or other outpatient visit, 60-74 minutes

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.

This service was performed 15 times for 15 patients

Telephone medical discussion with physician, 11-20 minutes

This is a service where you have a phone conversation with your doctor for 11-20 minutes. It's used for discussing health concerns, reviewing test results, or managing ongoing conditions. It's a convenient way to receive medical advice without an in-person visit.

This service was performed 18 times for 13 patients

Physician Visit Costs



The typical physician office visit costs for Medicare beneficiaries in this area are: $34.71 for a new patient copayment and $26.42 for an established patient copayment.

The pricing information below displays the copayment minimum, maximum and average amount that patients under Medicare are charged when visiting this provider as a new or established patient. Please keep in mind that these prices are just for reference purposes, and the actual prices charged by the provider might be different.

For patients covered under private health plans the prices below are also useful as healthcare pricing for private insurance is usually established as a function of Medicare prices. Private insurance covered patients should check their individual plans to determine the exact pricing.

The prices below reflect the costs for new and established patients in the 60661 ZIP code area.

New Patients Visit Costs *

The most utilized procedure code for new patients office visits is 99204

  • Average New Patient Price $138.86
  • Minimum New Patient Price $60.08
  • Maximum New Patient Price $183.39
  • Average New Patient Copayment $34.71
  • Minimum New Patient Copayment $15.02
  • Maximum New Patient Copayment $45.84

Established Patients Visit Costs *

The most utilized procedure code for established patients office visits is 99214

  • Average Established Patient Price $105.7
  • Minimum Established Patient Price $18.97
  • Maximum Established Patient Price $148.12
  • Average Established Patient Copayment $26.42
  • Minimum Established Patient Copayment $4.74
  • Maximum Established Patient Copayment $37.03

* The physician office visit costs information is generated by statistical analysis of similar providers in the same geographical area. The pricing information above IS NOT the amount charged by this provider.

Quality Reporting

The provider participated in CMS Quality Payment Program. The Quality Payment Program aims to improve population health, reduce costs and improve the care received by Medicare beneficiaries. The following quality measures meet Medicare's statistical reporting standards. Not all providers report the same information, because not all providers give the same services to patients. The quality information is just a snapshot of some the care providers give to their patients. Reporting more or less information is not a reflection of quality.

Quality Measure Performance Number of Patients
Documentation of Current Medications in the Medical Record 100% 809
Percentage of visits for patients aged 18 years and older for which the eligible professional or eligible clinician attests to documenting a list of current medications using all immediate resources available on the date of the encounter. This list must include ALL known prescriptions, over-the-counters, herbals, and vitamin/mineral/dietary (nutritional) supplements AND must contain the medications' name, dosage, frequency and route of administration
Implementation of medication management practice improvementsYesN/A
Manage medications to maximize efficiency, effectiveness and safety that could include one or more of the following: Reconcile and coordinate medications and provide medication management across transitions of care settings and eligible clinicians or groups; Integrate a pharmacist into the care team; and/or Conduct periodic, structured medication reviews.
Medication Reconciliation 95% 752
The MIPS eligible clinician performs medication reconciliation for at least one transition of care in which the patient is transitioned into the care of the MIPS eligible clinician.
Patient-Specific Education 83% 752
The MIPS eligible clinician must use clinically relevant information from CEHRT to identify patient-specific educational resources and provide access to those materials to at least one unique patient seen by the MIPS eligible clinician.
Preventive Care and Screening: Body Mass Index (BMI) Screening and Follow-Up Plan 100% 500
Percentage of patients aged 18 years and older with a BMI documented during the current encounter or during the previous twelve months AND with a BMI outside of normal parameters, a follow-up plan is documented during the encounter or during the previous twelve months of the current encounter Normal Parameters: Age 18 years and older BMI >= 18.5 and < 25 kg/m2
Rheumatoid Arthritis (RA): Assessment and Classification of Disease Prognosis 100% 169
Percentage of patients aged 18 years and older with a diagnosis of rheumatoid arthritis (RA) who have an assessment and classification of disease prognosis at least once within 12 months
Rheumatoid Arthritis (RA): Functional Status Assessment 100% 169
Percentage of patients aged 18 years and older with a diagnosis of rheumatoid arthritis (RA) for whom a functional status assessment was performed at least once within 12 months
Rheumatoid Arthritis (RA): Periodic Assessment of Disease Activity 100% 169
Percentage of patients aged 18 years and older with a diagnosis of rheumatoid arthritis (RA) who have an assessment and classification of disease activity within 12 months
Security Risk AnalysisYesN/A
Conduct or review a security risk analysis in accordance with the requirements in 45 CFR 164.308(a)(1), including addressing the security (to include encryption) of ePHI data created or maintained by certified EHR technology in accordance with requirements in 45 CFR164.312(a)(2)(iv) and 45 CFR 164.306(d)(3), and implement security updates as necessary and correct identified security deficiencies as part of the MIPS eligible clinician's risk management process.
Tobacco useYesN/A
Tobacco use: Regular engagement of MIPS eligible clinicians or groups in integrated prevention and treatment interventions, including tobacco use screening and cessation interventions (refer to NQF #0028) for patients with co-occurring conditions of behavioral or mental health and at risk factors for tobacco dependence.

Find Provider Hospital Affiliations - Privileges

Doctors and physicians must apply for hospital privileges to treat patients at hospitals. Find out if your doctor has privileges to practice at your preferred hospital by using the hospital affiliation information below based on recent medical claims.

Hospital affiliation is identified through self-reporting data, inpatient, outpatient, physician and ancillary service claims linked by the medical claims NPI number and place of service code. Additionally, to further determine provider hospital affiliation the clinician must have provided services to at least three patients on three different dates in the last 12 months. Siddharth Tambar is affiliated with the following medical facilities:

Hospital Name Address Phone Hospital Type Overall Rating
PRESENCE SAINT JOSEPH HOSPITAL - CHICAGO2900 NORTH LAKE SHORE DRIVE
CHICAGO, IL 60657
(773) 665-3000Acute Care Hospitals
NORTHWESTERN MEDICINE CENTRAL DUPAGE HOSPITAL25 NORTH WINFIELD ROAD
WINFIELD, IL 60190
(630) 682-1600Acute Care Hospitals
NORTHWESTERN MEMORIAL HOSPITAL251 E HURON ST
CHICAGO, IL 60611
(312) 926-2000Acute Care Hospitals

CLIA Information

The Clinical Laboratory Improvement Amendments (CLIA) of 1988 applies to facilities or sites that test human specimens for health assessment or to diagnose, prevent, or treat disease. The CLIA Program sets standards for clinical laboratory testing and issues certificates. The NPI / CLIA crosswalk information for this NPI number is:

CLIA Number
14D2183012
Facility Type
Physician Office
Certificate Effective Date
April 28, 2026
Certificate Expiration Date
April 27, 2028
Laboratory Director
SIDDHARTH TAMBAR M D
Certificate Type
Certificate of Waiver
Certificate Type Description
This CLIA certificate is issued to Siddharth Tambar to perform only waived tests. CLIA defines waived tests as simple tests with a low risk for an incorrect result. Waived tests include certain tests listed in CLIA regulations, tests cleared by the FDA for home use and tests approved by the FDA for waived status and that meet CLIA waiver criteria.

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NPI NPI Number Validation

How NPI Validation Works

The NPI validation process uses the ISO-standard Luhn algorithm, a mathematical "handshake", to ensure that a provider's 10-digit ID is authentic and free of common typing errors.

To verify the NPI 1477655488, we treat the final digit (8) as the Check Digit—the target answer we need to reach. The process begins by taking the first nine digits and adding a constant value of 24, which accounts for the "80840" prefix required for all U.S. health identifiers. We then double every other digit starting from the right and sum the individual digits of those results together. For this specific NPI, that total comes to 62. The final step is to find the difference between that total and the next multiple of ten (70 - 62 = 8).

Digit-by-digit view

Use the first nine digits for the calculation. Starting from the right, double every other digit. The last digit is the check digit and is not part of the calculation.

Pos 1
1
Doubled → 2
Pos 2
4
Unchanged
Pos 3
7
Doubled → 14 → 1 + 4
Pos 4
7
Unchanged
Pos 5
6
Doubled → 12 → 1 + 2
Pos 6
5
Unchanged
Pos 7
5
Doubled → 10 → 1 + 0
Pos 8
4
Unchanged
Pos 9
8
Doubled → 16 → 1 + 6
Check
8
Target digit
Regular digit Doubled digit Check digit

Step 1: Double every other digit from the right

Starting with the rightmost digit of the first nine digits, double every other value. If doubling creates a two-digit number, add those digits together.

1 → 2 7 → 14 → 5 6 → 12 → 3 5 → 10 → 1 8 → 16 → 7

Step 2: Add all digits plus the NPI constant

Add the transformed values, the unchanged digits, and the constant 24.

2 + 4 + 1 + 4 + 7 + 1 + 2 + 5 + 1 + 0 + 4 + 1 + 6 + 24 = 62

Step 3: Find the amount needed to reach the next multiple of 10

The next multiple of ten after 62 is 70. The difference is the calculated check digit.

70 - 62 = 8
This NPI is valid
The calculated check digit is 8, which matches the last digit of 1477655488.

Other Providers at the Same Location


The following 7 providers are registered at the same or a nearby location.

Dermatology
618 W FULTON ST
CHICAGO, IL 60661
Orthopaedic Surgery
618 W FULTON ST
CHICAGO, IL 60661
Physician Assistant
618 W FULTON ST
CHICAGO, IL 60661
Non-Pharmacy Dispensing Site
618 W FULTON ST
CHICAGO, IL 60661
Orthopaedic Surgery
618 W FULTON ST
CHICAGO, IL 60661
Internal Medicine (Rheumatology)
618 W FULTON ST
CHICAGO, IL 60661
Dermatology
618 W FULTON ST
CHICAGO, IL 60661

Frequently Asked Questions

The NPI number assigned to this healthcare provider is 1477655488, enumerated as an "individual" on September 01, 2006.

The provider is located at 618 W FULTON ST CHICAGO, IL 60661 and the phone number is (773) 348-7171.

Internal Medicine with taxonomy code 207RR0500X and a focus in Rheumatology.

Siddharth Tambar is affiliated with: PRESENCE SAINT JOSEPH HOSPITAL - CHICAGO, NORTHWESTERN MEDICINE CENTRAL DUPAGE HOSPITAL and NORTHWESTERN MEMORIAL HOSPITAL.