Providers Loreen O'Brien, MA, MED, MDIV, CRC to Michael O'Brien, DPT
300 individual NPIs in the federal registry, part 16,007 of 24,427 of the A to Z by surname. Each row is the registry's record: the name and credential, the NPI, the primary specialty, the practice city and the year the NPI was issued. 99 link to a page of their own with Medicare and CMS data the registry does not carry.
| Provider | NPI | Specialty | Practice city | NPI issued |
|---|---|---|---|---|
| Loreen O'Brien, MA, MED, MDIV, CRC | 1407213424 | Mental Health Counselor | Wesley Chapel, FL | 2016 |
| Loretta O'Brien | 1316542020 | Peer Specialist | Kennett, MO | 2020 |
| Loretta O'Brien, D.C. | 1801828488 | Chiropractor | Pacifica, CA | 2006 |
| Loretta O'Brien | 1962049692 | Occupational Therapist | Brooklyn, NY | 2019 |
| Lori O'Brien, M.A.CCC-SLP | 1346404910 | Speech-Language Pathologist | Plymouth Meeting, PA | 2008 |
| Lori O'Brien | 1588392971 | Mental Health Counselor | Toms River, NJ | 2022 |
| Lori O'Brien, M.ED/BCBA | 1770095457 | Behavior Analyst | Fort Lauderdale, FL | 2017 |
| Lori O'Brien, OTR/L | 1962915249 | Occupational Therapist | New City, NY | 2017 |
| Lorna O'Brien, RN | 1013123843 | Home Health Registered Nurse | Rochester, NY | 2007 |
| Lorrie O'Brien, MSW, LCSW, LICSW | 1659686780 | Clinical Social Worker | Enfield, CT | 2010 |
| Lucy O'Brien, D.O. | 1487911814 | Family Medicine Physician | Broadview Heights, OH | 2012 |
| Luke O'Brien | 1366062861 | Social Worker | Willimantic, CT | 2020 |
| Luke O'Brien, PT | 1508145293 | Physical Therapist | Vail, CO | 2011 |
| Lynae O'Brien | 1740698059 | Behavior Analyst | Boynton Beach, FL | 2014 |
| Lynette O'Brien, OTRL | 1245436062 | Occupational Therapist | Nashville, TN | 2007 |
| Lynn O'Brien, EDD,LPCC-S,NCC,RPT | 1205694825 | Mental Health Counselor | Le Sueur, MN | 2024 |
| Lynn O'Brien, MSW | 1225127608 | Marriage & Family Therapist | Brookfield, WI | 2006 |
| Lynn O'Brien, MT-BC | 1467743393 | Music Therapist | Minneapolis, MN | 2011 |
| Lynn O'Brien, ACSW, LCSW | 1770547226 | Clinical Social Worker | Forest Hills, NY | 2006 |
| Lynn O'Brien | 1861185969 | Speech-Language Pathologist | Salt Lake City, UT | 2023 |
| Lynne O'Brien, M.ED., BCBA | 1184001406 | Behavior Analyst | Mercer Island, WA | 2015 |
| Lynne O'Brien | 1720107279 | Marriage & Family Therapist | Long Beach, CA | 2007 |
| Lynne O'Brien, CRNA | 1821004920 | Certified Registered Nurse Anesthetist | Cincinnati, OH | 2006 |
| M. O'Brien, MD | 1992750863 | Anatomic Pathology & Clinical Pathology Physician | Mobile, AL | 2006 |
| M. Anne O'Brien, M.ED, LPC, LMFT, NCC | 1336361906 | Marriage & Family Therapist | Luling, LA | 2007 |
| M. Keith O'Brien | 1659772630 | Student in an Organized Health Care Education/Training Program | New Bedford, MA | 2014 |
| Macie O'Brien | 1932033438 | Behavior Technician | Knoxville, TN | 2026 |
| Macklin O'Brien, PHARMD | 1205364510 | Pharmacotherapy Pharmacist | Iowa City, IA | 2017 |
| Madeleine O'Brien | 1639647480 | Behavior Technician | Sacramento, CA | 2018 |
| Madeleine O'Brien | 1669674255 | Psychiatry Physician | Marcy, NY | 2007 |
| Madeline O'Brien | 1962032771 | Behavior Technician | San Diego, CA | 2020 |
| Madelyn O'Brien | 1871348243 | Counselor | Lawrence, MA | 2024 |
| Madison O'Brien, MD | 1124762505 | Obstetrics & Gynecology Physician | Little Rock, AR | 2022 |
| Madison O'Brien, SLP | 1265002943 | Speech-Language Pathologist | Portland, OR | 2021 |
| Madison O'Brien, RBT | 1437079969 | Behavior Technician | Clinton, MO | 2026 |
| Madison O'Brien | 1851973267 | Physician Assistant | Canton, GA | 2021 |
| Madison O'Brien, RMHCI | 1992668487 | Mental Health Counselor | Lake Mary, FL | 2025 |
| Maegan O'Brien, MS CCC-SLP | 1780217083 | Speech-Language Pathologist | Poplar Grove, IL | 2020 |
| Maeve O'Brien | 1326927435 | Registered Nurse | Nashville, TN | 2025 |
| Mai O'Brien | 1134958291 | Licensed Practical Nurse | Brooklyn, NY | 2024 |
| Maia O'Brien, PT | 1972717932 | Physical Therapist | Olympia, WA | 2007 |
| Malia O'Brien | 1366905671 | Counselor | Grass Valley, CA | 2019 |
| Mallorie O'Brien | 1851998090 | Physical Therapist | Wheat Ridge, CO | 2020 |
| Mallory O'Brien | 1033719596 | Registered Nurse | Clinton, TN | 2020 |
| Mallory O'Brien | 1487261186 | Mental Health Counselor | Bellingham, WA | 2020 |
| Mallory O'Brien, FNP-C | 1639311178 | Family Nurse Practitioner | Douglas, GA | 2009 |
| Mallory O'Brien, PA-C | 1700647948 | Physician Assistant | Lansing, MI | 2024 |
| Marcela O'Brien, MA | 1821278359 | Student in an Organized Health Care Education/Training Program | Portland, OR | 2007 |
| Marcia O'Brien, MSN, APRN, NP-C | 1053853176 | Family Nurse Practitioner | Austin, TX | 2016 |
| Marcus O'Brien, M.D. | 1215944772 | Pediatrics Physician | Little Rock, AR | 2006 |
| Marcy O'Brien, M.A. CCC-A, F-AAA | 1659551315 | Audiologist | Lakeland, FL | 2007 |
| Margaret O'Brien, MD | 1023048964 | Anesthesiology Physician | Bryn Mawr, PA | 2006 |
| Margaret O'Brien | 1023987377 | Behavior Technician | Winchester, VA | 2025 |
| Margaret O'Brien, LC | 1033320635 | Mental Health Counselor | Lanham, MD | 2007 |
| Margaret O'Brien, RN | 1134267339 | Child & Adolescent Psychiatric/Mental Health Registered Nurse | San Francisco, CA | 2007 |
| Margaret O'Brien | 1134700495 | Psychiatry Physician | Chicago, IL | 2021 |
| Margaret O'Brien, MA, JD | 1205972387 | Mental Health Counselor | Tewksbury, MA | 2007 |
| Margaret O'Brien, PT | 1285703314 | Physical Therapist | Hilton Head, SC | 2006 |
| Margaret O'Brien, GNP | 1437128642 | Gerontology Nurse Practitioner | Edina, MN | 2006 |
| Margaret O'Brien, LCAT, LMHC, BC-DMT | 1548817281 | Mental Health Counselor | New York, NY | 2019 |
| Margaret O'Brien, MD | 1639871080 | Dermatology Physician | Philadelphia, PA | 2023 |
| Margaret O'Brien, R.D. | 1659331536 | Registered Dietitian | Phoenix, AZ | 2006 |
| Margaret O'Brien, PT | 1669589354 | Physical Therapist | Plymouth, MN | 2006 |
| Margaret O'Brien | 1811542608 | Specialist | Victor, NY | 2019 |
| Margaret O'Brien | 1821309741 | Mental Health Counselor | Dorchester, MA | 2010 |
| Margaret O'Brien, LMHC | 1891246518 | Mental Health Counselor | Arlington, MA | 2016 |
| Margaret O'Brien | 1912505033 | Speech-Language Pathologist | Manteno, IL | 2020 |
| Margaret O'Brien | 1942275532 | Orthopedic Physical Therapist | Nas Whidbey, WA | 2006 |
| Margaret O'Brien, MPT LPT | 1942428891 | Physical Therapist | Woody Creek, CO | 2007 |
| Mari O'Brien, RN | 1154156297 | Registered Nurse | Boerne, TX | 2024 |
| Maria O'Brien, OTD, OTR/L | 1114809878 | Occupational Therapist | Chicago, IL | 2025 |
| Maria O'Brien, M.S. | 1124170667 | Professional Counselor | Waukesha, WI | 2007 |
| Maria O'Brien, M.D. | 1366429011 | Family Medicine Physician | Leonardtown, MD | 2005 |
| Maria O'Brien, PTA | 1487026464 | Physical Therapy Assistant | Reading, PA | 2015 |
| Maria O'Brien | 1952053639 | Registered Nurse | Warren, OH | 2022 |
| Maria O'Brien, LPC | 1982749602 | Professional Counselor | Shreveport, LA | 2007 |
| Maria O'Brien, MD | 1992718068 | Family Medicine Physician | Bristol, CT | 2006 |
| Mariah O'Brien, MSW, LCSW | 1730602095 | Clinical Social Worker | Brookline, MA | 2017 |
| Marian 'Micki' O'Brien, M.ED.,, L.P.C. | 1770664252 | Professional Counselor | Austin, TX | 2006 |
| Marianne O'Brien, MA SLP | 1083071633 | Speech-Language Pathologist | Torrance, CA | 2016 |
| Marie O'Brien, ANP | 1073860607 | Adult Health Nurse Practitioner | Port Jefferson, NY | 2012 |
| Marie O'Brien, D.O. | 1083836464 | Rheumatology Physician | Allentown, PA | 2007 |
| Marie O'Brien, MA, LPCC | 1760780415 | Professional Counselor | Minneapolis, MN | 2011 |
| Mariellen O'Brien | 1578697637 | Social Worker | Auburn, CA | 2007 |
| Marilyn O'Brien, RN | 1679657597 | Registered Nurse | Decatur, GA | 2006 |
| Marina O'Brien, PA-C | 1932923489 | Physician Assistant | Milwaukee, WI | 2024 |
| Marine O'Brien, LPN | 1336345016 | Licensed Practical Nurse | Burlington, NJ | 2007 |
| Marionne Joy O'Brien | 1417831744 | Addiction (Substance Use Disorder) Counselor | Anchorage, AK | 2025 |
| Marisa O'Brien, OD | 1124332234 | Optometrist | Saint Louis, MO | 2010 |
| Marisa O'Brien, RN | 1457739724 | Registered Nurse | Salem, NH | 2015 |
| Mark O'Brien, MD | 1124129267 | Family Medicine Physician | Carmel, IN | 2006 |
| Mark O'Brien | 1124796545 | Certified Registered Nurse Anesthetist | Plymouth, MN | 2021 |
| Mark O'Brien | 1174243976 | Certified Registered Nurse Anesthetist | Lewiston, ME | 2022 |
| Mark O'Brien, D.O. | 1255322509 | Family Medicine Physician | Saint Clair, MI | 2005 |
| Mark O'Brien, D.O. | 1265532212 | Pediatrics Physician | Fort Wayne, IN | 2006 |
| Mark O'Brien | 1295421758 | Student in an Organized Health Care Education/Training Program | New York, NY | 2023 |
| Mark O'Brien, D.O. | 1497744247 | Internal Medicine Physician | Vista, CA | 2005 |
| Mark O'Brien, LCSW-R | 1598072357 | Clinical Social Worker | Albion, NY | 2010 |
| Mark O'Brien, DC | 1770180895 | Chiropractor | El Dorado Hills, CA | 2020 |
| Mark O'Brien, MS, LCPC | 1932427986 | Professional Counselor | Chicago, IL | 2010 |
| Mark O'Brien, M.D. , M.P.H. | 1972726495 | Developmental - Behavioral Pediatrics Physician | Cranston, RI | 2007 |
| Marlene O'Brien, MD, PHD | 1467750422 | Family Medicine Physician | Turnersville, NJ | 2011 |
| Martha O'Brien, CRNA | 1356437081 | Certified Registered Nurse Anesthetist | Boston, MA | 2006 |
| Martha O'Brien, MS SLP/CCC | 1669465456 | Speech-Language Pathologist | Farmville, VA | 2005 |
| Martha O'Brien, APRN | 1770566689 | Adult Health Nurse Practitioner | Wethersfield, CT | 2005 |
| Mary O'Brien, MD | 1013902162 | Family Medicine Physician | Fort Wayne, IN | 2005 |
| Mary O'Brien, DPT | 1053230201 | Physical Therapist | Kansas City, MO | 2026 |
| Mary O'Brien, OTR | 1053435354 | Occupational Therapist | Kennett Square, PA | 2007 |
| Mary O'Brien, MD | 1083118863 | Obstetrics & Gynecology Physician | Louisville, KY | 2018 |
| Mary O'Brien, CNM | 1124177332 | Advanced Practice Midwife | Hermosa Beach, CA | 2007 |
| Mary O'Brien | 1134700750 | Behavior Analyst | Haddon Heights, NJ | 2021 |
| Mary O'Brien | 1174372130 | Mental Health Counselor | Pittsburgh, PA | 2024 |
| Mary O'Brien, LMSW | 1184199010 | School Social Worker | Cambria Heights, NY | 2018 |
| Mary O'Brien, L.P.C. | 1194874909 | Professional Counselor | Saint Louis, MO | 2007 |
| Mary O'Brien | 1275839433 | Mental Health Counselor | Lexington, MA | 2011 |
| Mary O'Brien, NMD, FNP | 1285750240 | Family Nurse Practitioner | Tempe, AZ | 2007 |
| Mary O'Brien, PT | 1285794230 | Physical Therapist | Colchester, VT | 2006 |
| Mary O'Brien, RN | 1295004125 | Registered Nurse | Schenectady, NY | 2011 |
| Mary O'Brien, PHD | 1306850490 | Psychologist | Los Angeles, CA | 2006 |
| Mary O'Brien, RN-C, FNP, MS | 1336276864 | Family Nurse Practitioner | Allendale, MI | 2007 |
| Mary O'Brien, SLP-A | 1346410586 | Developmental Therapist | Valrico, FL | 2008 |
| Mary O'Brien | 1386906154 | Physical Therapist | Amesbury, MA | 2012 |
| Mary O'Brien, LMHC | 1417358938 | Mental Health Counselor | Yakima, WA | 2014 |
| Mary O'Brien, PHARMD | 1417739970 | Pharmacist | Nottingham, MD | 2023 |
| Mary O'Brien | 1477938900 | Certified Registered Nurse Anesthetist | Cincinnati, OH | 2015 |
| Mary O'Brien | 1568316065 | Behavior Technician | Las Vegas, NV | 2026 |
| Mary O'Brien | 1578262606 | Behavior Technician | Montclair, CA | 2023 |
| Mary O'Brien, CRNP | 1578554887 | Primary Care Nurse Practitioner | Laurel, MD | 2005 |
| Mary O'Brien, LCPC | 1588834493 | Professional Counselor | Edgewater, MD | 2008 |
| Mary O'Brien, LCSW | 1598544371 | Clinical Social Worker | Peekskill, NY | 2023 |
| Mary O'Brien, RRT, NPS, AE-C | 1629393905 | Neonatal/Pediatric Registered Respiratory Therapist | Piscataway, NJ | 2010 |
| Mary O'Brien, PSYD | 1649133711 | Clinical Neuropsychologist | Lake Grove, NY | 2025 |
| Mary O'Brien, M.D. | 1659513570 | Pediatrics Physician | Houston, TX | 2009 |
| Mary O'Brien, RN | 1679826069 | School Registered Nurse | Nashville, TN | 2012 |
| Mary O'Brien, RN | 1720826936 | Addiction (Substance Use Disorder) Registered Nurse | Oak Harbor, WA | 2024 |
| Mary O'Brien, OTR/L | 1750680401 | Occupational Therapist | Tinley Park, IL | 2011 |
| Mary O'Brien, FNP | 1821176264 | Nurse Practitioner | Vestal, NY | 2006 |
| Mary O'Brien, MD | 1891635819 | Student in an Organized Health Care Education/Training Program | Tampa, FL | 2026 |
| Mary O'Brien, M.D. | 1912980434 | Internal Medicine Physician | Shrewsbury, MA | 2005 |
| Mary O'Brien, MD | 1952317927 | Family Medicine Physician | Tacoma, WA | 2006 |
| Mary O'Brien, LCSW, CASAC | 1962848820 | Clinical Social Worker | New York, NY | 2013 |
| Mary Clare O'Brien, MSP | 1689075913 | Mental Health Counselor | Fall River, MA | 2014 |
| Mary Ellen O'Brien, M.D. | 1144425000 | Internal Medicine Physician | Providence, RI | 2007 |
| Mary Jane O'Brien, RNP | 1831138320 | Pediatric Nurse Practitioner | East Boston, MA | 2006 |
| Mary Lou O'Brien, FNP | 1427500909 | Family Nurse Practitioner | Springboro, OH | 2016 |
| Mary Lynn O'Brien, M.D. | 1124115936 | Developmental - Behavioral Pediatrics Physician | Portland, OR | 2006 |
| Maryanne O'Brien, NP | 1851185789 | Women's Health Nurse Practitioner | Indianapolis, IN | 2025 |
| Maryellen O'Brien, LMHC | 1902284458 | Mental Health Counselor | Worcester, MA | 2015 |
| Marykate O'Brien, PA-C | 1396300430 | Physician Assistant | Greensboro, NC | 2019 |
| Masumi O'Brien, PTA | 1295857548 | Physical Therapy Assistant | Plymouth Meeting, PA | 2007 |
| Matthew O'Brien | 1083156525 | Athletic Trainer | Camp Hill, PA | 2016 |
| Matthew O'Brien, MD | 1376002600 | Psychiatry Physician | Atascadero, CA | 2019 |
| Matthew O'Brien | 1376160135 | Personal Care Attendant | Washington, DC | 2020 |
| Matthew O'Brien | 1376160267 | Technician | Sun Valley, CA | 2020 |
| Matthew O'Brien, M.D. | 1417210998 | Diagnostic Radiology Physician | Portland, OR | 2012 |
| Matthew O'Brien, DO | 1417577024 | Surgery Physician | Janesville, WI | 2020 |
| Matthew O'Brien, M.D. | 1417996935 | Family Medicine Physician | Wilmington, DE | 2006 |
| Matthew O'Brien, PA-C | 1518725779 | Physician Assistant | Palo Alto, CA | 2024 |
| Matthew O'Brien | 1538023007 | Behavior Technician | Concord, CA | 2025 |
| Matthew O'Brien, PT, DPT | 1588278949 | Physical Therapist | Westbrook, ME | 2020 |
| Matthew O'Brien, MD | 1790304137 | Pediatric Cardiology Physician | New Haven, CT | 2020 |
| Matthew O'Brien, PT, DPT | 1831039247 | Physical Therapist | Tucson, AZ | 2026 |
| Matthew O'Brien | 1871345256 | Student in an Organized Health Care Education/Training Program | Charlotte, NC | 2024 |
| Matthew O'Brien, PH.D. | 1871805838 | Psychologist | Iowa City, IA | 2010 |
| Matthew O'Brien, DC | 1932718160 | Independent Medical Examiner Chiropractor | Morgan Hill, CA | 2020 |
| Matthew O'Brien, PHD, ATC, LAT | 1942295316 | Athletic Trainer | Stillwater, OK | 2005 |
| Matthew O'Brien, PA-C | 1972847168 | Surgical Physician Assistant | Pittsburgh, PA | 2012 |
| Maura O'Brien, PHARM. D | 1043781826 | Pharmacist | Reno, NV | 2018 |
| Maura O'Brien | 1306450283 | Occupational Therapy Assistant | Findlay, OH | 2020 |
| Maura O'Brien, DNP, FNP-C | 1831960335 | Family Nurse Practitioner | Washington, DC | 2024 |
| Maureen O'Brien | 1013327626 | Occupational Therapist | Jacksonville, FL | 2014 |
| Maureen O'Brien, LCSW | 1124442645 | Clinical Social Worker | Waynesville, NC | 2014 |
| Maureen O'Brien, MS, CCC-SLP | 1205006970 | Speech-Language Pathologist | Pittsburgh, PA | 2008 |
| Maureen O'Brien | 1316585235 | Occupational Therapist | Indianapolis, IN | 2019 |
| Maureen O'Brien, MSW, LCSW, ACSW | 1326097817 | Clinical Social Worker | Albany, NY | 2006 |
| Maureen O'Brien, LCPC | 1366009086 | Professional Counselor | Baltimore, MD | 2019 |
| Maureen O'Brien, PHARMD | 1366291528 | Pharmacist | Ventura, CA | 2024 |
| Maureen O'Brien, M.D. | 1386891778 | Family Medicine Physician | Jacksonville, FL | 2008 |
| Maureen O'Brien, RN | 1467490573 | Home Health Registered Nurse | Racine, WI | 2006 |
| Maureen O'Brien, P.T. | 1528074127 | Physical Therapist | Bolivia, NC | 2006 |
| Maureen O'Brien, RD | 1558539817 | Registered Dietitian | Newark, DE | 2008 |
| Maureen O'Brien, OTR/L | 1639144827 | Neurorehabilitation Occupational Therapist | Fort Knox, KY | 2006 |
| Maureen O'Brien, PA | 1669663274 | Physician Assistant | Ithaca, NY | 2007 |
| Maureen O'Brien, MS, APRN, CNP | 1699911461 | Family Nurse Practitioner | Lincolnshire, IL | 2008 |
| Maureen O'Brien, M.D. | 1710194881 | Pediatric Hematology & Oncology Physician | Aurora, CO | 2007 |
| Maureen O'Brien, PA | 1740275148 | Surgical Physician Assistant | Annapolis, MD | 2005 |
| Maureen O'Brien, PHARMD | 1932433687 | Pharmacist | Bronx, NY | 2009 |
| Maureen O'Brien | 1952378390 | Physical Therapist | Wynantskill, NY | 2006 |
| Maureen O'Brien, M.D. | 1982716270 | Internal Medicine Physician | Burlington, MA | 2006 |
| Maurice O'Brien | 1275905382 | Case Manager/Care Coordinator | Lake Charles, LA | 2015 |
| McKenzie O'Brien | 1174384069 | Personal Care Attendant | South Charleston, WV | 2024 |
| McKenzie O'Brien | 1710749726 | Behavior Technician | Parker, CO | 2024 |
| Meagan O'Brien, PA | 1114379732 | Physician Assistant | Atlanta, GA | 2016 |
| Meaghan O'Brien, CTRS, QMHP | 1396581328 | Case Manager/Care Coordinator | Lafayette, CO | 2024 |
| Meaghan O'Brien, PA-C | 1659620839 | Physician Assistant | Grand Rapids, MI | 2012 |
| Meg O'Brien | 1578914099 | Pediatric Occupational Therapist | Colorado Springs, CO | 2016 |
| Megan O'Brien, FNP | 1033421110 | Community Health Nurse Practitioner | Burlington, VT | 2010 |
| Megan O'Brien, PA | 1073171591 | Physician Assistant | Hampton, IA | 2019 |
| Megan O'Brien | 1124557517 | Developmental Therapist | Milford, MA | 2017 |
| Megan O'Brien | 1134609076 | Electroneurodiagnostic Specialist/Technologist | Fairfield, NJ | 2018 |
| Megan O'Brien | 1205612082 | Occupational Therapist | Chubbuck, ID | 2023 |
| Megan O'Brien, CCC-SLP | 1205622263 | Speech-Language Pathologist | Indianapolis, IN | 2025 |
| Megan O'Brien | 1285023820 | Psychiatric/Mental Health Registered Nurse | Culver City, CA | 2015 |
| Megan O'Brien, OTR | 1346055449 | Occupational Therapist | Fredericksburg, VA | 2025 |
| Megan O'Brien | 1356748271 | Case Manager/Care Coordinator | New York, NY | 2014 |
| Megan O'Brien, LICSW | 1376363747 | Clinical Social Worker | Bellevue, WA | 2024 |
| Megan O'Brien, PHARMD | 1386858355 | Pharmacist | Lebanon, NH | 2007 |
| Megan O'Brien, LCPC | 1437424769 | Professional Counselor | Emporia, KS | 2012 |
| Megan O'Brien, PA-C | 1447739255 | Physician Assistant | Chicago, IL | 2018 |
| Megan O'Brien | 1467025122 | Behavior Technician | Irwin, PA | 2021 |
| Megan O'Brien | 1497607568 | Behavior Technician | Monrovia, CA | 2026 |
| Megan O'Brien, PT, DPT, NCS | 1508689456 | Neurology Physical Therapist | Loveland, CO | 2024 |
| Megan O'Brien | 1578600888 | Clinical Social Worker | Natick, MA | 2007 |
| Megan O'Brien, MSW, LCSW | 1598125445 | Clinical Social Worker | Pinedale, WY | 2016 |
| Megan O'Brien, MSPT | 1598790578 | Physical Therapist | Wellsville, NY | 2006 |
| Megan O'Brien, APRN | 1609020916 | Acute Care Nurse Practitioner | Lebanon, NH | 2008 |
| Megan O'Brien, RBT | 1730754961 | Behavior Technician | Edinburg, TX | 2021 |
| Megan O'Brien, PMHNP | 1750784559 | Psychiatric/Mental Health Nurse Practitioner | Berkeley, CA | 2014 |
| Megan O'Brien | 1760038509 | Family Nurse Practitioner | Marion, IA | 2019 |
| Megan O'Brien, LCSW | 1821617911 | Clinical Social Worker | Grayslake, IL | 2020 |
| Megan O'Brien, MFTI | 1831347541 | Mental Health Counselor | Novato, CA | 2008 |
| Megan O'Brien, MD | 1861029183 | Psychiatry Physician | San Francisco, CA | 2020 |
| Megan O'Brien | 1871137588 | Marriage & Family Therapist | Denver, CO | 2019 |
| Megan O'Brien | 1932853777 | Mental Health Counselor | Kenilworth, IL | 2022 |
| Megan O'Brien, M.A. CF-SLP | 1962926154 | Speech-Language Pathologist | Cary, NC | 2017 |
| Megan O'Brien, LCSW | 1992490221 | Clinical Social Worker | Gainesville, GA | 2023 |
| Meghan O'Brien | 1134803117 | Student in an Organized Health Care Education/Training Program | Nashua, NH | 2023 |
| Meghan O'Brien, APN | 1164774584 | Adult Health Nurse Practitioner | Orlando, FL | 2012 |
| Meghan O'Brien | 1184432312 | Adult Companion | Grand Island, NE | 2024 |
| Meghan O'Brien, FNP-C | 1215813548 | Family Nurse Practitioner | Norridge, IL | 2025 |
| Meghan O'Brien | 1225780406 | Pharmacist | Laramie, WY | 2022 |
| Meghan O'Brien, MD, MBE | 1245641539 | Internal Medicine Physician | San Francisco, CA | 2014 |
| Meghan O'Brien | 1326973108 | Professional Counselor | Omaha, NE | 2026 |
| Meghan O'Brien, LCSW | 1518174952 | Clinical Social Worker | Stratford, CT | 2007 |
| Meghan O'Brien, MD | 1740926328 | Family Medicine Physician | Salem, OR | 2022 |
| Meghan O'Brien, PMHNP-BC | 1821891052 | Psychiatric/Mental Health Nurse Practitioner | Fairfax, VA | 2025 |
| Meghan O'Brien, LMT | 1902037757 | Specialist | Sarasota, FL | 2009 |
| Meghan O'Brien, CCC-SLP | 1922284868 | Speech-Language Pathologist | Los Angeles, CA | 2008 |
| Melanie O'Brien | 1083409221 | Mental Health Counselor | San Antonio, TX | 2025 |
| Melanie O'Brien | 1932258555 | Developmental Therapist | Jacksonville, FL | 2007 |
| Melinda O'Brien | 1629873724 | Student in an Organized Health Care Education/Training Program | Tulsa, OK | 2025 |
| Melinda O'Brien, RPH | 1871103622 | Pharmacist | Johnstown, CO | 2020 |
| Melissa O'Brien, COTA/L | 1003144726 | Occupational Therapy Assistant | Voorhees, NJ | 2009 |
| Melissa O'Brien, MS CCC-SLP | 1023267432 | Speech-Language Pathologist | Niskayuna, NY | 2008 |
| Melissa O'Brien | 1104498005 | Behavior Analyst | Broomall, PA | 2021 |
| Melissa O'Brien, MS, RD, CSP, LDN | 1164042107 | Registered Dietitian | Memphis, TN | 2020 |
| Melissa O'Brien, PHARMD, BCACP | 1457663981 | Pharmacist | New Hyde Park, NY | 2010 |
| Melissa O'Brien, NP | 1629485578 | Psychiatric/Mental Health Nurse Practitioner | New York, NY | 2014 |
| Melissa O'Brien, RDH | 1770722746 | Dental Hygienist | Columbus, OH | 2009 |
| Melissa O'Brien, A.T.C. | 1932174059 | Athletic Trainer | Coudersport, PA | 2006 |
| Melvern O'Brien, RN | 1043855588 | Addiction (Substance Use Disorder) Registered Nurse | Chehalis, WA | 2019 |
| Melville O'Brien | 1801590641 | Internal Medicine Physician | Jacksonville, FL | 2023 |
| Meredith O'Brien, LCSW | 1558663641 | Clinical Social Worker | Freehold, NJ | 2010 |
| Meredith O'Brien, APRN, CRNA | 1780048702 | Certified Registered Nurse Anesthetist | Rochester, MN | 2016 |
| Merl O'Brien, M.D. | 1386687317 | Emergency Medicine Physician | Carmichael, CA | 2006 |
| Merrilee O'Brien, LMFT | 1538209218 | Mental Health Counselor | Torrance, CA | 2007 |
| Micah O'Brien, PTA | 1568830511 | Physical Therapy Assistant | Milwaukie, OR | 2015 |
| Miceal O'Brien | 1780833574 | Mental Health Counselor | Cherry Hill, NJ | 2008 |
| Michael O'Brien, RN | 1003408881 | Registered Nurse | Milford, MA | 2021 |
| Michael O'Brien, DO | 1043343056 | Internal Medicine Physician | North Conway, NH | 2007 |
| Michael O'Brien | 1043686462 | Pulmonary Disease Physician | Pittsburgh, PA | 2015 |
| Michael O'Brien, MSPT | 1063582468 | Physical Therapist | Tumwater, WA | 2006 |
| Michael O'Brien, MD | 1093394082 | Orthopaedic Surgery Physician | Birmingham, AL | 2021 |
| Michael O'Brien, PA-C | 1104887884 | Physician Assistant | Halfmoon, NY | 2006 |
| Michael O'Brien, MD | 1104960657 | Sports Medicine (Orthopaedic Surgery) Physician | New Orleans, LA | 2007 |
| Michael O'Brien, D.O. | 1124361720 | Anesthesiology Physician | Canton, OH | 2013 |
| Michael O'Brien, CMII | 1134583883 | Case Manager/Care Coordinator | Norman, OK | 2016 |
| Michael O'Brien, MD | 1144203241 | Internal Medicine Physician | La Crosse, WI | 2005 |
| Michael O'Brien, DDS | 1164448635 | Dentist | Northampton, MA | 2006 |
| Michael O'Brien | 1194539924 | Mental Health Counselor | Portland, OR | 2025 |
| Michael O'Brien, M.D. | 1194777888 | Diagnostic Radiology Physician | Waukesha, WI | 2006 |
| Michael O'Brien, M.D. | 1215257100 | Internal Medicine Physician | King Of Prussia, PA | 2010 |
| Michael O'Brien | 1215337134 | Pharmacist | Mt Pleasant, SC | 2014 |
| Michael O'Brien, DO | 1245081454 | Internal Medicine Physician | Park Ridge, IL | 2024 |
| Michael O'Brien, PTA | 1285092882 | Physical Therapy Assistant | Louisville, KY | 2016 |
| Michael O'Brien, CRNP | 1295082725 | Family Nurse Practitioner | Beaver, PA | 2012 |
| Michael O'Brien, CADC II, NCAC I | 1295173854 | Addiction (Substance Use Disorder) Counselor | Sonoma, CA | 2013 |
| Michael O'Brien, MD | 1306842661 | Orthopaedic Surgery Physician | Edgewood, KY | 2005 |
| Michael O'Brien, PHD | 1326011669 | Clinical Social Worker | Indianapolis, IN | 2006 |
| Michael O'Brien, M.D. | 1386175701 | Neurological Surgery Physician | Waterbury, CT | 2017 |
| Michael O'Brien, M.D. | 1386628170 | Family Medicine Physician | Poland, OH | 2005 |
| Michael O'Brien, DDS, JD | 1407065162 | Oral and Maxillofacial Surgery (Dentist) | Baton Rouge, LA | 2007 |
| Michael O'Brien | 1417672114 | Behavior Technician | Fresno, CA | 2022 |
| Michael O'Brien, MD | 1437738168 | Pediatrics Physician | Washington, DC | 2021 |
| Michael O'Brien, CASE MANAGER | 1447639612 | Case Manager/Care Coordinator | Denver, CO | 2015 |
| Michael O'Brien | 1508611658 | Student in an Organized Health Care Education/Training Program | Nashville, TN | 2024 |
| Michael O'Brien, ADC-T | 1518687243 | Addiction (Substance Use Disorder) Counselor | Saint Paul, MN | 2022 |
| Michael O'Brien, M.D. | 1528037710 | Orthopaedic Surgery Physician | La Follette, TN | 2006 |
| Michael O'Brien, M.EQ. | 1548395114 | Psychologist | Saint Paul, MN | 2007 |
| Michael O'Brien, MD | 1598907453 | Family Medicine Physician | Reno, NV | 2009 |
| Michael O'Brien, RN | 1629081310 | Administrator Registered Nurse | Leeds, MA | 2006 |
| Michael O'Brien, DMD | 1629451067 | Dentist | Okmulgee, OK | 2015 |
| Michael O'Brien, DDS | 1629480363 | General Practice Dentistry | Raleigh, NC | 2014 |
| Michael O'Brien, M.D. | 1649502675 | Specialist | West Lake Hills, TX | 2010 |
| Michael O'Brien, BCBA | 1699291393 | Behavior Analyst | Jeffersonville, IN | 2017 |
| Michael O'Brien, MD | 1700858438 | Anatomic Pathology Physician | Boston, MA | 2006 |
| Michael O'Brien | 1710875927 | Social Worker | West Des Moines, IA | 2025 |
| Michael O'Brien, MD | 1720168172 | Vascular & Interventional Radiology Physician | Lakewood, CO | 2006 |
| Michael O'Brien, MD, FAAEM | 1720357353 | Emergency Medicine Physician | Buffalo, NY | 2011 |
| Michael O'Brien, DPT | 1720455892 | Physical Therapist | White Oak, PA | 2015 |
Source: CMS National Plan and Provider Enumeration System (NPPES) (download.cms.gov). A listing is not a recommendation: check a license with the state board (license lookups).