John Whitney Mercer Jr., MD

Primary specialty

Obstetrics & Gynecology PhysicianTaxonomy code 207V00000X

License

3971468 Issued in ID

Practice address

4424 E Flamingo Ave Ste 200
Nampa, ID 83687-9300

Phone

(208) 302-1400

Fax

(208) 302-1455

NPI assigned

Jan 17, 2007

Sex

Male

Sole proprietor

Yes

Registry information is reported by the provider to CMS and is not verified. About this source

Specialties & licenses 3

Addresses

Other identifiers 3

Medicare fee-for-service enrollment

Enrolled in LA, WY, CO, ID4 enrollments

Eligible to order & refer

• Part B services: Yes
• Medical equipment: Yes
• Home health: Yes
• Power mobility devices: Yes
• Hospice: Yes

Green means eligible to order or refer.

Enrollment records 4

Specialty

Obstetrics/Gynecology

Education

Other, 1997

Medicare assignment

Accepts the Medicare-approved amount as payment in full

Group practices

Saint Alphonsus Regional Medical Center IncGroup PAC ID 3476462359, 672 clinicians

Minden Physician Practices LLCGroup PAC ID 4789720004, 48 clinicians

Practice addresses (Care Compare)

Hospital & facility affiliations

• Minden Medical Center Hospital, Minden, LA, CCN 190144

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine

State licenses

Practice roles

Locations

Interoperability endpoints

• Direct secure messaging: jmercer4610543@direct.trinity-health.org
• Direct secure messaging: minjmerce@yourcarecommunity.org
• Direct secure messaging: john.mercer.jr.1@3681.direct.athenahealth.com
• Direct secure messaging: john.mercer.1@3681.direct.athenahealth.com

Organizations this provider is connected to: Medicare benefit reassignments (the organization bills Medicare for this provider’s services), Care Compare group memberships and National Provider Directory roles.

• Saint Alphonsus Regional Medical Center Inc

  • Psychologist
  • Boise, ID
  • NPI 1649357716
  Medicare reassignment Care Compare group NPD
• Minden Physician Practices LLC

  • Multi-Specialty Clinic/Center
  • Minden, LA
  • NPI 1497986764
  Medicare reassignment Care Compare group NPD
• Casper Obstetrical and Gynecological Associates PC

  • Obstetrics & Gynecology Physician
  • Casper, WY
  • NPI 1134272917
  Medicare reassignment NPD
• DHP of Louisiana PC

  • Obstetrics & Gynecology Physician
  • Alexandria, LA
  • NPI 1013303056
  Medicare reassignment NPD
• Intermountain Medical Group Grand Junction, LLC

  • Orthopaedic Surgery Physician
  • Grand Junction, CO
  • NPI 1356765556

  Obstetrics & Gynecology

  Medicare reassignment NPD
• Obhg Colorado, P.C.

  • Obstetrics & Gynecology Physician
  • Colorado Springs, CO
  • NPI 1104116896
  Medicare reassignment NPD
• Obhg Louisiana, LLC

  • Obstetrics & Gynecology Physician
  • Greenville, SC
  • NPI 1639567316

  LA

  Medicare reassignment NPD
• Obhg Wyoming PC

  • Obstetrics & Gynecology Physician
  • Casper, WY
  • NPI 1346055068
  Medicare reassignment NPD
• Women'S Health Associates of Monroe

  • Obstetrics & Gynecology Physician
  • Monroe, LA
  • NPI 1821171497
  NPD (past) Authorized official
• Saint Alphonsus Regional Medical Center Inc

  • Psychiatric Hospital Unit
  • Boise, ID
  • NPI 1770687857
  NPD
• Saint Alphonsus Regional Medical Center Inc

  • Family Medicine Physician
  • Caldwell, ID
  • NPI 1861676298

  Obstetrics & Gynecology

  NPD
• Intermountain Medical Group Grand Junction, LLC

  • Durable Medical Equipment & Medical Supplies
  • Grand Junction, CO
  • NPI 1609737618
  NPD

Hospitals and other facilities this clinician is affiliated with according to Medicare Care Compare.

• CLHG - Minden, LLC

  • Rural Acute Care Hospital
  • Minden, LA
  • NPI 1891873337
  Care Compare affiliation

The complete NPPES record for this NPI in the NPI Registry API format.

{
    "created_epoch": "1168992000000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1756771200000",
    "number": "1205988540",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "715 S 3RD ST",
            "city": "MONTROSE",
            "state": "CO",
            "postal_code": "814014209",
            "telephone_number": "970-249-6737",
            "fax_number": "970-252-0112"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "4424 E FLAMINGO AVE STE 200",
            "city": "NAMPA",
            "state": "ID",
            "postal_code": "836879300",
            "telephone_number": "208-302-1400",
            "fax_number": "208-302-1455"
        }
    ],
    "practiceLocations": [
        {
            "address_1": "715 S 3rd St",
            "address_purpose": "LOCATION",
            "city": "Montrose",
            "state": "CO",
            "postal_code": "814014209",
            "country_code": "US",
            "telephone_number": "970-249-6737",
            "fax_number": "970-252-0112",
            "country_name": "United States",
            "address_type": "DOM"
        },
        {
            "address_1": "900 S 4th St",
            "address_purpose": "LOCATION",
            "city": "Montrose",
            "state": "CO",
            "postal_code": "814014226",
            "country_code": "US",
            "telephone_number": "970-249-6737",
            "fax_number": "970-252-0112",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "basic": {
        "last_name": "MERCER",
        "first_name": "JOHN",
        "middle_name": "WHITNEY",
        "name_prefix": "Dr.",
        "name_suffix": "Jr.",
        "credential": "MD",
        "sole_proprietor": "YES",
        "sex": "M",
        "enumeration_date": "2007-01-17",
        "last_updated": "2025-09-02",
        "certification_date": "2025-09-02",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207V00000X",
            "taxonomy_group": "",
            "desc": "Obstetrics & Gynecology",
            "state": "LA",
            "license": "L023779",
            "primary": false
        },
        {
            "code": "207V00000X",
            "taxonomy_group": "",
            "desc": "Obstetrics & Gynecology",
            "state": "CO",
            "license": "CDR.0000210",
            "primary": false
        },
        {
            "code": "207V00000X",
            "taxonomy_group": "",
            "desc": "Obstetrics & Gynecology",
            "state": "ID",
            "license": "3971468",
            "primary": true
        }
    ],
    "identifiers": [
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "STATE LICENSE",
            "identifier": "L023779",
            "state": "LA"
        },
        {
            "code": "05",
            "desc": "MEDICAID",
            "issuer": null,
            "identifier": "9000166884",
            "state": "CO"
        },
        {
            "code": "05",
            "desc": "MEDICAID",
            "issuer": null,
            "identifier": "1487163",
            "state": "LA"
        }
    ],
    "endpoints": [],
    "other_names": []
}

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• Obstetrics & Gynecology Physician in Nampa, ID
• Providers in Nampa, ID by specialty
• Obstetrics & Gynecology Physician in Idaho

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Sep 2, 2025; self-reported and not verified by CMS. Specialty names from the NUCC taxonomy.
• Medicare enrollment (CMS PECOS): enrollments, PAC IDs and benefit reassignments; Order and Referring.
• Medicare Care Compare (CMS): clinician profile, group practices, facility affiliations, MIPS scores and star ratings.
• National Provider Directory (CMS): practice roles, locations, licenses, networks and endpoints.

Verify at the official NPI Registry.