| Siddoway, Paul MD | SJMG Cardiac Interpretations | |
| Sidhu , Manavjot MD | SVH Montana Heart Institute | (406) 237-5001 |
| Sievers, Chad PA-C | Holy Rosary Healthcare | (406) 233-2600 |
| Sievers, Chad PA-C | Holy Rosary Healthcare Clinic | (406) 233-2500 |
| Silk, David MD | SJMG Emergency Physicians | (406) 723-2585 |
| Silva, Shurron FNP | PURE Infusion Suites of MT LLC - Billings | (406) 702-1327 |
| Silva, Shurron FNP | PURE Infusion Suites of MT LLC - Great Falls | (406) 384-7002 |
| Sims, David MD | SVHC Heart & Vascular Center | (406) 238-6820 |
| Sirek, Roger DC | Billings Chiropractic Injury Clinic | (406) 969-3805 |
| Sironi, Rindo MD | Billings OB\GYN Associates, PC | (406) 248-3607 |
| Skarda, David MD | SVHC Fortin Pediatric Specialty Clinic | (406) 237-5300 |
| Skelly, Sarah PA-C | SVHC Heart & Vascular Center | (406) 238-6820 |
| Slyngstad, Tyler MD | SVH Montana Heart Institute | (406) 237-5001 |
| Slyngstad, Tyler MD | SJMG Heart Center | (406) 723-2420 |
| Smith, Marty LAC, LCPC | Rimrock Foundation | (406) 248-3175 |
| Smith, Wanda LCPC | Wanda M. Smith, PLLC | (406) 690-1616 |
| Smith, Donald DC | Meier Chiropractic - West | (406) 651-5433 |
| Smith, Donald DC | Meier Chiropractic - Downtown | 406) 651-5433 |
| Smith, Angela PA-C | Big Horn Hospital | (406) 665-2310 |
| Sneddon, Scott PT | Red Lodge Physical Therapy | (406) 446-3850 |
| Sneddon, Scott PT | SVHC OCC Health | (406) 237-8855 |
| Snyder, Ronald MD | SVH Hospitalists | (406) 237-3850 |
| Snyder, Ronald MD | SVPN Intensivists | (406) 237-7200 |
| Snyder, Amy PA | SVHC Billings Transitional Care | (406) 237-8282 |
| Sorensen, Neal MD | SVHC Internal Medicine | (406) 238-6900 |
