MS. MELISSA NASTACIO PA-C
NPI 1982113007
Physician Assistant - Medical in San Francisco, CA

NPI Status: Active since September 20, 2017

Contact Information

2 EMBARCADERO CTR LBBY LEVEL
SAN FRANCISCO, CA
ZIP 94111
Phone: (888) 663-6331
Fax: (415) 252-7176

NPI Profile Information
Primary Taxonomy
Secondary Locations
Medicare Participation & PECOS Status
NPI Validation
Other Providers Same Location
Frequently Asked Questions

Individual
Female
Physician Assistant
Medical
PECOS Enrolled

About MELISSA NASTACIO

This page provides the complete NPI Profile along with additional information for Melissa Nastacio, a primary care provider established in San Francisco, California with a medical specialization in Physician Assistant, focusing in medical . The healthcare provider is registered in the NPI registry with number 1982113007 assigned on September 2017. The practitioner's primary taxonomy code is 363AM0700X with license number 54679 (CA). The provider is registered as an individual and her NPI record was last updated one year ago.

NPI: 1982113007
Provider Name: MS. MELISSA NASTACIO PA-C
Gender: Female
Entity Type: Individual
Location Address: 2 EMBARCADERO CTR LBBY LEVEL SAN FRANCISCO, CA 94111
Location Phone: (888) 663-6331
Location Fax: (415) 252-7176
Mailing Address: 1 EMBARCADERO CTR STE 1900 SAN FRANCISCO, CA 94111
Mailing Phone: (415) 658-6791
Is Sole Proprietor?: No
Enumeration Date: 09-20-2017
Last Update Date: 03-17-2025
Code Navigator

A primary care provider (PCP) like Melissa Nastacio sees people with common medical problems. The primary care provider might be a doctor, physician assistant, nurse practitioner or clinic that are usually involved in your long-term care. A PCP might provide preventive care, treat common medical conditions, identify urgent medical problems and refer you to specialists when necessary. Primary care is usually provided in an outpatient facility but if you are admitted to a hospital your PCP may assist in your care. The most common medical conditions seen by primary care providers are: hypertension, upper respiratory tract infections, depression or anxiety, back pain, arthritis, dermatitis, diabetes, urinary tract infections, etc .

Location Map

Secondary Locations

1680 E Capitol Expy Ste 10
San Jose, CA 95121
(408) 645-7096

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: Physician Assistant Medical
Taxonomy Code: 363AM0700X
Type: Physician Assistants & Advanced Practice Nursing Providers
License No.: 54679
License State: CA

Medicare Participation & PECOS Enrollment Status

Melissa Nastacio 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
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

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 1982113007, we treat the final digit (7) 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 53. The final step is to find the difference between that total and the next multiple of ten (60 - 53 = 7).

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

Doubled → 2

Pos 2

Unchanged

Pos 3

Doubled → 16 → 1 + 6

Pos 4

Unchanged

Pos 5

Doubled → 2

Pos 6

Unchanged

Pos 7

Doubled → 6

Pos 8

Unchanged

Pos 9

Doubled → 0

Check

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 8 → 16 → 7 1 → 2 3 → 6 0 → 0

Step 2: Add all digits plus the NPI constant

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

2 + 9 + 1 + 6 + 2 + 2 + 1 + 6 + 0 + 0 + 24 = 53

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

The next multiple of ten after 53 is 60. The difference is the calculated check digit.

60 - 53 = 7

This NPI is valid

The calculated check digit is 7, which matches the last digit of 1982113007.