Registry data as of Aug 27, 2026

Find an organization's NPI

52 active organization NPIs are registered under names beginning "Keystone Service Systems". Each location can bill under its own NPI, so add the city to find the one you need.

1 to 25 of 52, exact name first

  1. Keystone Service Systems, INC

    Case Management Agency · Westminster, MD · issued Apr 11, 2007

    1992928600
  2. Keystone Service Systems, INC

    Community/Behavioral Health Agency · Westminster, MD · issued Apr 18, 2007

    1952527749
  3. Keystone Service Systems

    Community/Behavioral Health Agency · Westminster, MD · issued Apr 18, 2007

    1861618654
  4. Keystone Service Systems, INC

    Community/Behavioral Health Agency · Bellefonte, PA · issued Mar 23, 2007

    1306963426
  5. Keystone Service Systems

    Community/Behavioral Health Agency · Chambersburg, PA · issued Mar 13, 2012

    1912272717
  6. Keystone Service Systems, INC

    Community/Behavioral Health Agency · Chambersburg, PA · issued Jan 19, 2016

    1063879211
  7. Keystone Service Systems, INC

    Counselor · Conshohocken, PA · issued Apr 21, 2010

    1902123680
  8. Keystone Service Systems INC

    Community/Behavioral Health Agency · Folsom, PA · issued Jan 21, 2016

    1750748794
  9. Keystone Service Systems, INC

    Community/Behavioral Health Agency · Gardners, PA · issued Jan 19, 2016

    1194182329
  10. Keystone Service Systems INC

    Community/Behavioral Health Agency · Hanover, PA · issued Aug 2, 2019

    1548815038
  11. Keystone Service Systems, INC

    Intellectual & Developmental Disabilities Psychologist · Harrisburg, PA · issued Dec 19, 2006

    1568525640
  12. Keystone Service Systems, INC

    Community/Behavioral Health Agency · Harrisburg, PA · issued Mar 23, 2007

    1154448280
  13. Keystone Service Systems, INC

    Community/Behavioral Health Agency · Harrisburg, PA · issued Mar 26, 2007

    1497872170
  14. Keystone Service Systems, INC

    Community/Behavioral Health Agency · Harrisburg, PA · issued Mar 26, 2007

    1770600454
  15. Keystone Service Systems, INC

    Community/Behavioral Health Agency · Harrisburg, PA · issued Apr 6, 2007

    1689797631
  16. Keystone Service Systems

    Community/Behavioral Health Agency · Harrisburg, PA · issued Apr 6, 2007

    1437272473
  17. Keystone Service Systems, INC

    Physical Therapist · Harrisburg, PA · issued Apr 6, 2007

    1346363389
  18. Keystone Service Systems, INC

    Community/Behavioral Health Agency · Harrisburg, PA · issued Feb 19, 2008

    1639347057
  19. Keystone Service Systems

    Community/Behavioral Health Agency · Harrisburg, PA · issued Apr 1, 2009

    1619119989
  20. Keystone Service Systems

    Community/Behavioral Health Agency · Harrisburg, PA · issued Apr 1, 2009

    1518109883
  21. Keystone Service Systems, INC

    Community/Behavioral Health Agency · Harrisburg, PA · issued Apr 7, 2009

    1205079241
  22. Keystone Service Systems, INC

    Community/Behavioral Health Agency · Harrisburg, PA · issued Jan 13, 2016

    1730545203
  23. Keystone Service Systems, INC

    Community/Behavioral Health Agency · Harrisburg, PA · issued Feb 5, 2016

    1497113393
  24. Keystone Service Systems, INC

    Community/Behavioral Health Agency · Harrisburg, PA · issued Mar 11, 2016

    1710348255
  25. Keystone Service Systems INC

    Community/Behavioral Health Agency · Harrisburg, PA · issued Mar 26, 2024

    1366292989

Source: CMS NPPES monthly file of Aug 9, 2026, organization (Type 2) records.