Alyssa Grossen MD
About this NPIWhat this record shows.
NPI 1912498411 is registered to Alyssa Grossen MD, a Gastroenterology practising at 20 York St in New Haven, Connecticut. Gastroenterology is a recognised medical specialty under the National Uniform Claim Committee (NUCC) taxonomy. Alyssa Grossen MD has been enumerated in the National Provider Identifier (NPI) registry since 2018.
Beyond the registryWhat this record adds.
This record carries 1 secondary identifier beyond the base NPI: Medicaid and other payer cross-references used by billers and credentialers, which the standard CMS NPPES lookup does not surface. It is enrolled in Medicare, linking to 2 PECOS enrollment records (each with a public Medicare Enrollment ID) sourced from CMS, which the NPPES registry does not list. Within the directory it is one of 382 Gastroenterology providers on file in Connecticut.
Source: CMS NPPES and PECOS public files. snapshot, refreshed monthly.
Your brand here.
Secondary identifiers
Additional identifiers this provider has registered with NPPES. Used by medical billers, credentialers, and insurance verifiers to cross-reference claims and enrollments.
Medicaid
Source: NPPES public registry.
Medicare enrollment
This provider holds 2 Medicare enrollments on file with the Provider Enrollment, Chain and Ownership System (PECOS). Each enrollment carries a public Medicare Enrollment ID (ENRLMT_ID) used by billers and intermediaries.
Practitioner
- I20210825000164Internal MedicineOK
- I20250522003331GastroenterologyCT
Source: CMS PECOS public enrollment file.
Insurance & acceptsHow to confirm coverage.
The National Plan and Provider Enumeration System (NPPES) registry does not include commercial insurance network data, so we cannot show which plans Alyssa Grossen MD accepts. To confirm in-network status with your specific health plan, contact Alyssa Grossen MD directly at (203) 688-4242.
Frequently asked
Yes. NPI 1912498411 is registered as Active in the CMS NPPES public registry and passes the Luhn check-digit validation that all 10-digit NPIs use.
Gastroenterology is a recognised medical specialty under the National Uniform Claim Committee (NUCC) taxonomy.
The CMS NPPES Public Registry at npiregistry.cms.hhs.gov is the authoritative source. FindMyNPI mirrors this dataset and refreshes monthly. For real-time verification, you can also call the provider's office at (203) 688-4242.
An individual healthcare provider has a single Type-1 NPI for life. Organisations can hold separate Type-2 NPIs per location, specialty, or sub-entity. Alyssa Grossen MD is a Type-1 individual NPI.
As of the latest monthly CMS NPPES snapshot, 382 Gastroenterology providers are registered in Connecticut, and Alyssa Grossen MD is one of them. The figure refreshes each month from the federal source.