DR. OLIVIA ANNA JEAN BEGASSE DE DHAEM M.D.
NPI 1639557408
Psychiatry & Neurology - Neurology in Stamford, CT
NPI Status: Active since May 13, 2015
Contact Information
90 MOGAN STREET
SUITE 305-306
STAMFORD, CT
ZIP 06902
Phone: (203) 306-2949
Fax: (203) 884-8939
- Individual
- Female
- Psychiatry & Neurology
- Neurology
- PECOS Enrolled
- Opted-Out Medicare
About OLIVIA BEGASSE DE DHAEM
This page provides the complete NPI Profile along with additional information for Olivia Begasse De Dhaem, a provider established in Stamford, Connecticut with a medical specialization in Psychiatry & Neurology, focusing in neurology . The healthcare provider is registered in the NPI registry with number 1639557408 assigned on May 2015. The practitioner's primary taxonomy code is 2084N0400X with license number 64919 (CT). The provider is registered as an individual and her NPI record was last updated February 2026.
- NPI
- 1639557408
- Provider Name
- DR. OLIVIA ANNA JEAN BEGASSE DE DHAEM M.D.
- Gender
- Female
- Entity Type
- Individual
- Location Address
- 90 MOGAN STREET SUITE 305-306 STAMFORD, CT 06902
- Location Phone
- (203) 306-2949
- Location Fax
- (203) 884-8939
- Mailing Address
- 90 MOGAN STREET SUITE 305-306 STAMFORD, CT 06902
- Mailing Phone
- (203) 306-2949
- Mailing Fax
- (203) 884-8939
- Is Sole Proprietor?
- Yes
- Enumeration Date
- 05-13-2015
- Last Update Date
- 02-02-2026
- Code Navigator
The provider doesn't accept Medicare and has signed an affidavit to be excluded from the Medicare program. If you are a Medicare beneficiary this means a provider can charge whatever they want for services rendered but must follow certain rules to do so. Olivia Begasse De Dhaem opted out of Medicare effective on 04-01-2025 until 04-01-2027. Opt out periods last for two years and cannot be terminated unless the provider is opting out for the very first time and the affidavit is terminated no later than 90 days after the opt out effective date. Opt-out affidavits might renew automatically renew every two years. The provider opted out of Medicare but is permitted to order and refer services to other healthcare providers.
Location Map
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
Psychiatry & Neurology Neurology
- Taxonomy Code
- 2084N0400X
- Type
- Allopathic & Osteopathic Physicians
- License No.
- 64919
- License State
- CT
- Taxonomy Description
- A Neurologist specializes in the diagnosis and treatment of diseases or impaired function of the brain, spinal cord, peripheral nerves, muscles, autonomic nervous system, and blood vessels that relate to these structures.
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) |
|---|---|---|---|---|
| 1 | 2084N0400X | Allopathic & Osteopathic Physicians | Psychiatry & Neurology | 277815 (MA) |
Medicare Participation & PECOS Enrollment Status
Olivia Begasse De Dhaem 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
Opted-Out of Medicare? Yes
Opt-Out Effective Date: 04-01-2025
Opt-Out End Date: 04-01-2027
Eligible to Order and Refer? Yes
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
Physician Visit Costs
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 06902 ZIP code area.
New Patients Visit Costs *
The most utilized procedure code for new patients office visits is 99204
- Average New Patient Price $138.84
- Minimum New Patient Price $60.82
- Maximum New Patient Price $183.1
- Average New Patient Copayment $34.71
- Minimum New Patient Copayment $15.2
- Maximum New Patient Copayment $45.77
Established Patients Visit Costs *
The most utilized procedure code for established patients office visits is 99214
- Average Established Patient Price $106.68
- Minimum Established Patient Price $19.76
- Maximum Established Patient Price $149.26
- Average Established Patient Copayment $26.67
- Minimum Established Patient Copayment $4.94
- Maximum Established Patient Copayment $37.31
* 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.
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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 1639557408, 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.
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.
Step 2: Add all digits plus the NPI constant
Add the transformed values, the unchanged digits, and the constant 24.
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.
Frequently Asked Questions
The NPI number assigned to this healthcare provider is 1639557408, enumerated as an "individual" on May 13, 2015.
The provider is located at 90 MOGAN STREET SUITE 305-306 STAMFORD, CT 06902 and the phone number is (203) 306-2949.
Psychiatry & Neurology with taxonomy code 2084N0400X and a focus in Neurology.
