Emergency Medical Services Radio

VHF Frequencies

150.7750   EMS (simplex)
150.7900   EMS (simplex)
152.0075   EMS (paging)
155.1600   EMS (also a common SAR frequency)
155.1750   EMS
155.2050   EMS
155.2200   EMS
155.2350   EMS
155.2650   EMS
155.2800   EMS
155.2950   EMS
155.3250   EMS 
155.3400   EMS to Hospital (HEAR)
155.3550   EMS
155.3850   EMS
155.4000   EMS
163.2500   EMS (paging)

These frequencies are also often used for other purposes which may or may not be EMS related such as ambulance dispatch and fire department tactical.

UHF Frequencies

The UHF "Med" channels 1-8 (some regions use different names, such as "Mednet") are used by Emergency Medical Technicians to communicate with the hospital. Information transmitted may be as little as the patient's age, sex, and general condition or as extensive as a full diagnostic workup.

In some areas, Paramedics are only able to give certain treatments under authority of an MD or specially-trained RN. This type of traffic is on the decline as well as Paramedics are given more independent treatment authority.

Analog transmission of electrocardiograms was quite common in the early days of modern EMS, but these modulated 1000 Hz tones are heard less and less as more and more EMS medical traffic is handled via cell phone.

Med channels 9 and 10 were added later below the original band of 8 and each has a specific listed purpose. Both are dispatch related, however, as opposed to medical control for channels 1-8. This is not always practiced, though, as sometimes the lower channels may be used for dispatch as well.

The UHF frequencies are assigned in pairs. In semi-duplex mode the higher frequency of the pair is usually used by the mobile while the lower frequency is used by the base (usually a hospital). Some EMS systems have the system configured for full-duplex where both parties can transmit and recieve at the same time. In many areas, they are configured as repeaters on mountaintops with the hospitals transmitting and receiving the same as any mobile. PL tones are selected by the ambulance crew to select which hospital hears the traffic, since many hospitals may be able to hear the same repeater on a particular pair.

Med channels 11-103 are "splinter" frequencies added even later. They are situated between the original existing channels and all would probably have to be narrowband to prevent adjacent channel interference if they were used in close proximity.

Mobile Rx	Mobile Tx	Name
463.00000	468.00000	Med 1
463.02500	468.02500	Med 2
463.05000	468.05000	Med 3
463.07500	468.07500	Med 4
463.10000	468.10000	Med 5
463.12500	468.12500	Med 6
463.15000	468.15000	Med 7
463.17500	468.17500	Med 8

462.95000	467.95000	Med 9
462.97500	467.97500	Med 10

463.00625	468.00625	Med 11
463.01250	468.01250	Med 12
463.01875	468.01875	Med 13
463.03125	468.03125	Med 21
463.03750	468.03750	Med 22
463.04375	468.04375	Med 23
463.05625	468.05625	Med 31
463.06250	468.06250	Med 32
463.06875	468.06875	Med 33
463.08125	468.08125	Med 41
463.08750	468.08750	Med 42
463.09375	468.09375	Med 43
463.10625	468.10625	Med 51
463.11250	468.11250	Med 52
463.11875	468.11875	Med 53
463.13125	468.13125	Med 61
463.13750	468.13750	Med 62
463.14375	468.14375	Med 63
463.15625	468.15625	Med 71
463.16250	468.16250	Med 72
463.16875	468.16875	Med 73
463.18125	468.18125	Med 81
463.18750	468.18750	Med 82
463.19375	468.19375	Med 83
462.95625	467.95625	Med 91
462.96250	467.96250	Med 92
462.96875	467.96875	Med 93
462.98125	467.98125	Med 101
462.98750	467.98750	Med 102
462.99375	467.99375	Med 103

Early on, there were four other frequencies, another 5 MHz below Meds 2, 4, 6, and 8 (458.02500, 458.0750, 458.1250, 458.1750). These were used by Paramedics to relay medical and telemetry traffic from the patient's location to the ambulance or rescue vehicle and then again to the hospital or other medical control. Like the Med channels themselves, they are now all in the public safety frequency pool.