CHRISTYN SIEVE PSYD PSYCHOLOGICAL SERVICES PLLC
NPI 1326636903
Clinic/Center - Adult Mental Health in Portsmouth, NH
About Christyn Sieve Psyd Psychological Services Pllc NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
CHRISTYN SIEVE PSYD PSYCHOLOGICAL SERVICES PLLC (NPI 1326636903) is a healthcare organization registered as an adult mental health in Portsmouth, New Hampshire and active in the NPI registry since January 2021. The organization lists Christyn B Sieve, Clinical Psychologist, as its authorized official.
NPPES Registry Identity
Specialties & Licenses
Medicare Participation & PECOS CMS
Medicare enrollment and the clinicians who bill Medicare through this organization, from CMS.
Medicare Enrollment Status
Enrolled in Medicare (PECOS)
Christyn Sieve Psyd Psychological Services Pllc is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).
Clinicians Billing Medicare Through This Organization
Medicare enrollment records show 1 clinician reassigns Medicare billing to Christyn Sieve Psyd Psychological Services PLLC, which bills Medicare for the services this clinician delivers.
Clinician (1)
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Frequently Asked Questions NPPES & CMS
Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.
What is Christyn Sieve Psyd Psychological Services PLLC's NPI number?
The NPI number for Christyn Sieve Psyd Psychological Services PLLC is 1326636903. It was assigned to this organization in the NPPES registry on January 8, 2021.
Where is Christyn Sieve Psyd Psychological Services PLLC located?
Christyn Sieve Psyd Psychological Services PLLC is located at 439 Middle St, Portsmouth, NH 03801. The listed phone number is (603) 498-1575.
What is Christyn Sieve Psyd Psychological Services PLLC's specialty?
The primary specialty registered for this NPI is Clinic/Center, specializing in Adult Mental Health, with taxonomy code 261QM0850X.
Is Christyn Sieve Psyd Psychological Services PLLC enrolled in Medicare?
Yes. Christyn Sieve Psyd Psychological Services PLLC is registered in the Medicare PECOS enrollment system.
How many clinicians bill Medicare through Christyn Sieve Psyd Psychological Services PLLC?
According to the CMS Revalidation Reassignment List (October 2026 release), 1 clinician (Clinical Psychologist) reassigns their Medicare billing to Christyn Sieve Psyd Psychological Services PLLC. A reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for the clinician's services. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
When was this NPI record last updated?
The NPPES record for Christyn Sieve Psyd Psychological Services PLLC was last updated on January 8, 2021. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 5 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.
# Christyn Sieve Psyd Psychological Services Pllc · NPI 1326636903
Adult Mental Health organization in Portsmouth, New Hampshire. Organization record, active in the CMS NPPES registry since January 8, 2021.
## Identity
- **NPI:** 1326636903 (Entity type: Organization)
- **Enumerated:** January 8, 2021
- **Primary specialty:** Clinic/Center - Adult Mental Health · taxonomy 261QM0850X
- **Organization subpart:** No
- **Authorized official:** Christyn Sieve, CLINICAL PSYCHOLOGIST
## Practice location
- **Address:** 439 MIDDLE ST, Portsmouth, NH 03801-5080
- **Phone:** (603) 498-1575
## Medicare
- **Medicare:** Enrolled in Medicare (PECOS)
- **Clinicians billing through this organization:** 1 clinician (Clinical Psychologist) reassigns Medicare billing to this organization (form CMS-855R) · CMS Revalidation Reassignment List, October 2026 release
## Record status
- **NPPES last updated:** January 8, 2021
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Source: [NPI Profile](https://npiprofile.com/npi/1326636903) · Data from the CMS NPPES public registry.