Today’s military medical system incorporates five echelons, or levels, of care that begin with the wounding, injury or illness and extend through the eventual evacuation and treatment in the continental United States (CONUS). Each succeeding echelon builds upon the abilities of forward levels by adding a new increment of treatment capability. Within a theater of operations, the first four echelons of medical support are characterized not only by increasing levels of medical sophistication but also by distance and access to aeromedical evacuation assets. 

First echelon care begins at the non-medical unit level and incorporates self-aid, buddy-aid, on-site medic or corpsman assistance; physician care is routinely available at within the unit at an aid station. Care focuses upon casualty examination, lifesaving measures (airway, bleeding, shock), and preparation for further evacuation. Treatment examples include surgical airway restoration, intravenous (IV) administration of-fluids, use of antibiotics, and application of bandages and splints. A typical first echelon medical facility would be an Army or Marine Corps battalion aid station (BAS). 

Second echelon care is provided at a medical facility by a team of physicians and supporting technical staff. It always includes the ability to perform resuscitation and stabilization and may include surgery, basic laboratory, pharmacy, radiology, and dental capabilities as well. Often, second echelon units are able to hold patients for up to 72 hours and may be able to administer group O blood transfusions. Care focuses upon emergency procedures to prevent probable death or loss of limb or body functions; however, treatment does not exceed measures dictated by immediate need. Typical second echelon facilities are Army and Marine Corps medical companies and Navy primary casualty receiving and treatment ships (PCRTS). 

Third echelon care facilities are the first places capable of providing in-patient medical care. Third echelon care includes the ability to hold patients for extended periods of time. These facilities provide the first step toward restoration of functional health and always include the ability to perform preoperative diagnostic procedures, intensive surgical preparation, general anesthesia, and postoperative care. A relatively wide range of blood products is available including fresh frozen plasma, platelets, and O, A, and B liquid cells. Typical third echelon facilities are the deployable medical system (DEPMEDS) hospitals used by all services and the Navy’s hospital ships. 

Fourth echelon care is usually provided at a fixed medical treatment facility located outside the JOA, but probably within the theater of operations. Fourth echelon hospitals are staffed and equipped to provide definitive, rehabilitative care to return casualties to duty. These medical treatment facilities are the final in-theater hospitals. 

Fifth echelon care is also provided by fixed medical treatment facilities. Fifth echelon hospitals are located within CONUS and are staffed and equipped to provide convalescent, restorative, and rehabilitative services in addition to definitive and specialized medical care. 

First Echelon Medical Facilities

Navy. Afloat first echelon care is performed within sick bay spaces. Medical care on smaller vessels is usually limited to independent duty corpsmen. 

Air Force. First echelon care provided to operational Air Force units is limited to self- or buddy-aid. Sometimes casualty collection points may be designated to assist in the care of wounded personnel. 

Second Echelon Medical Facilities

Army. The Army provides second echelon medical care at medical companies. Army medical companies are found within main or forward support battalions (FSB/MSB) that support combat divisions, regiments, or separate brigades. They are also found within corps level medical brigades, medical groups, or area support medical battalions that care for rear area combat service support troops. 

FSB medical companies are placed in direct support of brigade size combat forces and are composed of a company headquarters, and evacuation platoon, and a treatment platoon. The evacuation platoon usually contains a mix of tracked and wheeled ambulances that evacuate patients from a BAS. The treatment platoon is designed to set up a clearing station that can receive patients, perform triage, provide dental care, and treat medical patients. Surgery is limited to that which can be performed under local anesthesia, unless the medical company is augmented by a forward surgical team (FST). 

A MSB medical company is assigned to each division to provide direct support to units operating in the division rear area and backup support to the forward medical companies. Compared with an FSB medical company, each MSB medical company has a larger ambulance platoon, larger treatment and dental sections, multiple patient holding sections (each with a forty cot capacity), a preventive medicine section, an optometry section, a mental health section, and a Division Medical Supply Office (DMSO) that manages all medical materiel for the division. Like the forward medical companies, these units can only perform limited surgical procedures. The operation employment of divisional main and forward medical companies is coordinated by the Division Medical Operations Center (DMOC) assigned to the Division Support Command (DISCOM). Comparable MOCs coordinate medical company employment within combat regiments and separate brigades. 

Corps-level medical companies perform similar functions although they take on a variety of configurations and sizes. Often these units have either a pure evacuation or pure treatment mission. For example, a corps level medical holding company consists of five platoons, each with 240 cots for a total holding capacity of 1,200 patients.

The battalion's headquarters and support company includes eight mobile shock-trauma platoons that provide echelon one level medical care.  These platoons can be combined or collocated and readily lend themselves to task organized support for smaller MAGTFs.  They may also be used to augment or relieve battalion aid stations (BASs).  

Medical battalions also have three assigned surgical support companies.  A full-sized surgical support company is designed to provide general support from a relatively stable location; its structure and organiztion does not support rapid displacement and relocation, however it is able to divide into independent elements.  Each company contains three operating rooms and and a 60-cot holding section.  Ancillary services include two laboratories, two pharmacies, and two x-ray sections.  Dental support is provided by augmentation from the Dental Battalion

Medical battalions within the Marine Corps Reserve have maintained their old organization and consisting of collecting and clearing companies and surgical support companies.  Collecting and clearing companies provide services similar to Army forward and main medical companies, however they have a much greater surgical capability. Each contains two operating rooms and a 60-cot holding section. Reserve surgical support companies are much larger than collecting and clearing companies and, in fact, are designed to be divided into two sections, each about the size of a collecting and clearing company, should this be required during task organization. Each reserve surgical support company contains five operating rooms and a holding area for about 150 casualties.

The medical section of an aircraft carrier, though small when compared with Army or Marine Corps medical companies, is sufficient to provide HSS to a carrier battle group (CBG). Carriers have two operatories and can provide holding for about 50 patients. Several physicians and dentists are assigned in addition to about 30 corpsmen and 15 dental technicians. 

In each amphibious task force (ATF) usually at least one amphib (amphibious transport ship) designated as a PCRTS. This vessel provides second echelon care to the ATF and to ground forces during the initial phase of an amphibious assault. Medical capabilities of amphibs vary considerably by class. Larger ships, like general purpose amphibious assault ships (LHA), helicopter amphibious assault ships (LPH), or multipurpose amphibious assault ships (LHD) have up to six operating rooms and can hold between 200 and 600 patients. It should be remembered that PCRTS holding capacity consists mostly of bunks that are be occupied by marines in the assault force. Therefore, PCRTS holding capacity is usually not available until after an assault force has left the ship. 

Should additional medical assistance be required, the Navy can deploy fleet surgical teams (FST) or mobile medical augmentation readiness teams (MMART). There are six types of MMARTs: surgical teams, medical regulating teams, specialist teams, special psychiatric rapid intervention teams (SPRINT), preventive medicine teams, and humanitarian support teams.

Each ATC is designed to support between 300 and 500 personnel and is staffed by a physician and three medical technicians. Although it has no surgical capability, it can hold six patients in cots for up to three days. 

Although designed primarily as a third echelon facility, a 14-bed ATH variant called Coronet Bandage may be deployed to provide second echelon support. It can care for limited acute trauma, perform minor surgery, and provide minimal inpatient care.

Third Echelon Hospitals

Army  

The mobile Army surgical hospital (MASH) is employed relatively far forward—possibly even collocated with a division’s MSB medical company—and is designed to provide early surgical intervention and stabilization. It has four operating tables and 32 hospital beds. Typically, two MASH units are deployed to support a five-division corps. Each MASH requires six acres to completely lay out all facilities.  MASH units are being deactivated and replaced by more rapidly deployable Forward Surgical Teams. 

The combat support hospital (CSH) typically contains 316 hospital beds and is configured with the following bed allocation: 96 intensive care, 160 intermediate care, 20 neuropsychiatric, and 40 minimal care. It has four operating rooms with eight operating tables and can provide more advanced dental care than can a second echelon medical company. It provides stabilization for further patient evacuation. Depending upon the military mission, up to three CSHs may be deployed in support of a division. 

The Field Hospital can be used as either a third or fourth echelon facility. It typically contains 524 hospital beds; 24 intensive care, 160 intermediate care, 20 neuropsychiatric, and 320 minimal care. With one operating room of 2 operating tables, it is designed to provide in-theater treatment for patients not requiring further evacuation (e.g. during Desert Shield/Desert Storm, one field hospital had the primary mission of holding psychiatric patients.). It is well suited to providing care for EPW.

There are two hospital ships (TAH), the USNS COMFORT and USNS MERCY. Each has twelve operating rooms and a capacity of 500 hospital bed (80 intensive care, 20 recovery, 280 intermediate care, 120 light care) and 500 "overflow" or holding spaces. 

The Navy can also deploy 100, 200, or 500 bed Fleet Hospitals as third echelon facilities. the 100-bed hospital has one operating room with two tables, on 12-bed postoperative care ward, and four 20-bed intermediate care wards. The 250-bed hospital has two operating rooms, 36 intensive care beds, and 220 acute care beds. The 500-bed hospital has three operating rooms, 84 intensive care beds, and 420 acute care beds.

Fourth and Fifth Echelon Hospitals

Army. The primary Army fourth echelon deployable hospital is the General Hospital. It has eight operating tables and 476 beds: 96 intensive care, 20 neuropsychiatric, 320 intermediate, and 40 minimal. Like the CSH, it provides stabilization for further patient evacuation and is well suited to serving as a primary conduit into an intertheater evacuation system. The Army’s Field Hospitals can also be employed as fourth echelon facilities. 

Navy. The Navy fourth echelon deployable hospital is a variation of the 500-bed Fleet Hospital. Although it has three operating rooms like the third echelon 500-bed hospital, it has a different bed mix: 40 intensive care, 300 acute care, and 160 minimal care. 

Table 2 summarizes the military system of echeloned care. Remember that, as capability to provide care increases, the mobility of the medical unit usually decreases.

Determining Bed Requirements

As might be expected, a recently assigned JTF Surgeon will often have neither the time, expertise, equipment, nor background information to effectively use these programs. Should a surgeon be required to compute maximum bed requirements without the use of these systems, a relatively easy—though—generic way to do so is described in the Allied Command Europe (ACE) Directive 85-8, ACE Medical Support Principles, Policies, and Planning Parameters. 

Estimating Medically Significant Casualties  

Begin with casualty estimates provided by the JTF personnel officer (J1). These estimates will include multiple categories, such as killed in action (KIA), absent without leave (AWOL), and captured, that have no bearing upon medical holding and hospitalization requirements. Ignore these categories, and concentrate on those that do apply: wounded in action (WIA), battle stress (BS), and DNBI. 

If the J1 has only aggregate casualty estimates, you can determine the medical casualty estimate by using the standard ACE percentage factors in Table 3.

In each casualty category, the sum of the percentage returned to duty plus the percentage admitted to the hospital must equal 100% of the total number of casualties in that category. For example, if the aggregate casualty estimate for one day is 100, 58 of them will be wounded in action. Of those 58, 90% (or 52.2) will require admission to a hospital and 10% (or 5.8) will be returned to duty within 72 hours.

Hospital bed requirements are directly related to the operational evacuation policy. The evacuation policy is primarily determined by the unified command in charge of the operation and limits the number of days casualties may remain in theater hospital beds before being evacuated or returned to duty. Note that the evacuation policy does not require casualties to remain in theater a certain number of days before evacuation, it sets a limit on the maximum time they may remain in theater hospital beds. For example, if the combat zone evacuation policy is set at seven days, patients whose anticipated hospitalization is greater than seven days should be evacuated as soon as possible; patients whose hospitalization is anticipated to be less than seven days should remain in theater and be returned to duty from third echelon facilities. 

While evacuation policies differ between operations, an evacuation policy of seven days is typical for many limited operations that would require the activation of a JTF. 

Table 4 can be used to estimate hospital bed requirements for an operation with a seven-day evacuation policy.

Pre-Hostilities Bed Requirement (PHBR)* = (D x .04 x 5) + (D x .06 x 2) + (NBI x .01 x 4) + (NBI x .59 x 2) 

During Hostilities Bed Requirement** = (PHBR) + (WIA x .01 x 4) + (WIA x .89 x 2) + (BS x .10 x 2)