Aegis BMD or Aegis Ashore is a mid-course interceptor (extra-atmospheric), so the SM-3 can get that high. Guam has a THAAD battery or two, which can also get up to the top of the atmosphere (at Mach 9.5+). Ideally, the systems would operate together, with Aegis launching first and THAAD doing the mop-up if anything got through.
I’m still pitching for them to refurbish those Wake Island launch sites. For... reasons.