There are several different ICD-10-CM code sections that can be used when coding for auto accident injuries. Injury diagnosis codes in ICD-10-CM are found with leading alpha characters S and T. S codes are injuries related to a single body region. T codes are injuries to multiple or unspecified body regions, poisoning, and certain other consequences of external causes. V codes are used for transport accidents and generally have 4 characters.

ICD-10-CM may have from three to seven characters, Generally, the three-character codes are actually headings of sections, although some are complete codes.

One example of a three-character code is I10, Essential (primary) hypertension.

S Code Structure

S-Codes are used for injuries related to a single body region. They are listed in order of affected body region and then the type of injury. Notice below how the codes are structured according to body region first, starting at the head and ending at the foot in the "S" section.

• Head S00-S09
• Neck S10-S19
• Thorax S20-S29
• Abdomen, lower back, lumbar spine, pelvis, and external genitals S30-S39
• Shoulder and upper arm S40-S49
• Elbow and forearm S50-S59
• Wrist and hand S60-S69
• Hip and thigh S70-S79
• Knee and lower leg S80-S89
• Ankle and foot S90-S99

The 2nd Character indicates the part of the body 0 through 9:

S0 = Injury>Head

The 3rd character is decided according to the nature of the injury:

• 0 Superficial injuries
• 1 Open wounds
• 2 Fractures
• 3 Dislocations and sprains
• 4 Injuries of nerves
• 5 Blood vessels
• 6 Muscle and tendon
• 7 Crushing injury
• 8 Traumatic amputation
• 9 Other and unspecified injuries

Examples of a dissected injury 'S' code

S02.5  > S single body region > 0 injury to head > 2 fracture > .5 tooth

S21.1 > S single body region> 2 injury to thorax > 1 open wound > .1 front wall of thorax

T Code Structure

• Multiple body regions T07
• Unspecified body region T14
• Effects of foreign body entering through natural orifice T15-T19
• Burns and corrosions T20-T32
• Frostbite T33-T34
• Poisoning by adverse effects of and underdosing of drugs, medicaments, and biological substances T36-T50 
• Toxic effects of chiefly nonmedicinal substances T51-T65
• Other & unspecified effects of external causes T66-T78
• Certain early complications of trauma T79
• Complications of surgical and medical care, NEC T80-T88 

V Code Structure

• Transport accidents V01-V99 

The 2nd character is used to identify the mode of transportation.

• Pedestrian V01-V09
• Pedal cycle rider V10-V19
• Motorcycle rider V20-V29
• Occupant of three-wheeled motor vehicle V30-V39
• Car occupant V40-V49
• Occupant of pick-up truck or van V50-V59
• Occupant in heavy transport vehicle V60-V69
• Bus occupant V70-V79
• Other land transport V80-V89
• Water transport V90-V94
• Air and space transport V95-V97
• Other and unspecified transport V98-V99

The 3rd character identifies the circumstance of the accident.

• 0 In collision with pedestrian or animal
• 1 In collision with pedal cycle
• 2 In collision with 2 or 3 wheeled mv
• 3 In collision with car, pick-up, or van
• 4 In collision with heavy transport vehicle or bus
• 5 In collision with railway train
• 6 In collision with other nonmotor vehicle
• 7 In collision with fixed or stationary object
• 8 In noncollision transport accident
• 9 In other and unspecified transport accidents

The 4th character identifies whether the victim is the driver or passenger, and whether the incident occurred in traffic or a non-traffic situation.

• 0 Driver injured in nontraffic accident
• 1 Passenger injured in nontraffic accident
• 2 Person on outside of vehicle injured in nontraffic accident
• 3 Unspecified bus occupant injured in nontraffic accident
• 4 Person injured while boarding or alighting
• 5 Driver injured in traffic accident
• 6 Passenger injured in traffic accident
• 7 Person on outside of vehicle injured in traffic accident
• 8 Occupant [any] in other specified transport accident
• 9 Unspecified bus occupant injured in traffic accident

Other External Causes of Morbidity Codes

There are a few other code ranges that can be used when coding auto accident injuries (Note that these are not complete codes and will need to be reported with additional characters). 

• Intentional self-harm by crashing of motor vehicle X82
• Assault by pushing or placing victim in front of moving object Y02
• Assault by crashing of motor vehicle Y03 

For a complete list of 2019 ICD-10-CM Guidelines, click here.