| PSIGEN Software, Inc. | Alabama |
| Psilera | |
| PsiQuantum | California |
| PSISM, LLC | Maryland |
| PsiThera | |
| PSNResearch | |
| Psomagen | Maryland |
| Psoria-Shield, Inc. | New York |
| PSS Consulting | |
| PSSC Labs | California |
| PSSI Global Services, LLC | |
| PSST Seamless Data Solutions | Kentucky |
| PSTuners | Arizona |
| Psy Therapeutics, Inc. | |
| PsychBiller, LLC | Virginia |
| Psyche Systems Corporation | Massachusetts |
| Psycheceutical Bioscience, Inc. | |
| Psychiz Networks | California |
| PsychoGenics, Inc. | New Jersey |
| Psychology Software Tools, Inc. | Pennsylvania |
| PsychoTech, LLC | |
| Psyonix, Inc. | California |
| Psyquel | Texas |
| PsyTech VR, Inc. | |
| PT Consulting Partners, Inc. | Texas |
| Pt Pal | |
| PT Wired | North Carolina |
| PTC | Massachusetts |
| PTC Therapeutics, Inc. | |
| PTD Technology | |
| Ptera | Washington |
| PtEverywhere | North Carolina |
| PTG International | Maryland |
| PTI Security Systems | Arizona |
| PTIGlobal | |
| PTM Biolabs, Inc. | Illinois |
| PTM Therapeutics | |
| Ptolemay | |
| Ptolemy Consulting Group | Indiana |
| PTS Diagnostics | Indiana |
| PTS Solutions, Inc. | Louisiana |
| PTSinnovations, Inc. | Illinois |
| PTV Healthcare Capital | Texas |
| Pubgenius, Inc. | |
| Public Access Networks Corporation | New York |
| Public Advertising Agency | |
| Public Alliance, LLC | |
| Public Domain Aeronautical Software | California |
| Public Good, Inc. | |
| Public Health Management Corporation | |