One of the new concepts ICD-10-CM introduces is the seventh character. As coders have prepared for ICD-10-CM, they have raised questions about how to select the correct seventh character. Coders can find some of the answers in the ICD-10-CM Official Guidelines for Coding and Reporting and the American Hospital Associations's (AHA) Coding Clinic for ICD-10, First Quarter 2015.
In general, only codes in the following three chapters require seventh characters:
- 15, Pregnancy, Childbirth, and the Puerperium
- 19, Injury, Poisoning, and Certain Other Consequences of External Causes
- 20, External Causes of Morbidity
Pregnancy seventh characters
For codes in Chapter 15, the seventh character denotes the specific fetus affected by certain conditions, says Nelly Leon-Chisen, RHIA, director of coding and classification for AHA. Those conditions are found in the following subcategories:
- O31, complications specific to multiple gestation
- O32, maternal care for malpresentation of fetus
- O33, maternal care for disproportion (but only for codes 033.3-O33.6)
- O35, maternal care for known or suspected fetal abnormality and damage
- O36, maternal care for rhesus isoimmunization
- O40, polyhydramnios
- O41, other disorders of amniotic fluid and membranes
- O60.1, preterm labor with preterm delivery
- O60.2, term delivery with preterm labor
- O64, obstructed labor due to malposition and malpresentation of fetus
- O69, labor and delivery complicated by umbilical cord complications
Note that the codes begin with a capital letter O, but additional characters within the code use the number zero.
Coders can choose from the following seventh characters:
0, not applicable or unspecified
1, fetus 1
2, fetus 2
3, fetus 3
4, fetus 4
5, fetus 5
9, other fetus
If the patient is only carrying one child, coders will always use seventh character 0, says Leon-Chisen. Coders will also use 0 when the physician doesn’t specify which fetus is affected for multiple gestations and coders are unable to get additional clarification. In some cases, the physician will not be able to specify which fetus is affected. In those cases, report seventh character 0.
For example, if a patient is seen for maternal care for breech presentation of fetus 1, report ICD-10-CM code O32.1XX1. If a patient is seen for maternal care for fetal hydrocephalus affecting fetus 2, report code O35.0XX2.
Both of these codes also require coders to assign an additional code from category O30 (multiple gestation), so coders need to pay careful attention to the notes, says Leon-Chisen.
Injury seventh characters
For injuries (except fractures) and poisonings, coders have three seventh character choices to represent the episode of care:
- A, initial encounter
- D, subsequent encounter
- S, sequela
Coders will choose the seventh character based on what type of treatment the patient is receiving, Leon-Chisen says. It does not matter whether the patient is seeing a particular provider for the first time.
Think of seventh character A as active treatment, says Jennifer E. Avery, CCS, CPC-H, CPC, CPC-I, AHIMA-approved ICD-10-CM/PCS trainer, senior regulatory specialist and Boot Camp instructor for HCPro, a division of BLR, in Danvers, Massachusetts.
Consider this scenario: A high school lacrosse player suffers a closed nondisplaced oblique fracture of the right tibia following a collision with another player during an away game. The player is treated at the local ED and instructed to follow up with his personal physician.
For the ED visit, the coder assigned these codes:
- S82.234A, nondisplaced oblique fracture of right tibia, initial encounter
- W03.XXXA, fall on same level in collision with another person, initial encounter
- Y92.328, other athletic field as the place of occurrence of the external cause
- Y93.65, activity, lacrosse
- Y99.8, other external cause status (student activity)
The player follows up with his primary care physician (PCP) three days later and the PCP refers the patient to an orthopedist for surgery.
For the visit with the PCP, coders would report:
- S82.234A, nondisplaced oblique fracture of right tibia, initial encounter
- W03.XXXA, fall on same level in collision with another person, initial encounter
Because the lacrosse player’s fracture was not yet in the healing stage, the seventh character remains A, Avery says. When the patient is seen by the orthopedic surgeon, coders will report the same codes again.
In the past, the ICD-10-CM Official Guidelines for Coding and Reporting listed evaluation and management by a new physician as an example of an initial encounter. The Cooperating Parties revised the guideline examples for active treatment to:
- Surgical treatment
- ED encounter
- Evaluation and continuing treatment by the same or a different physician
Seventh character D is used for encounters after the patient has received active treatment of the condition and is receiving routine care for the condition during the healing or recovery phase. Examples of subsequent care are:
- Cast change or removal
- An x-ray to check healing status of fracture
- Removal of external or internal fixation device
- Medication adjustment
- Other aftercare and follow up visits following treatment of the injury or condition
ICD-10-CM does include aftercare Z codes, but coders should not assign those codes for conditions such as injuries or poisonings, Leon-Chisen says. Instead, coders should use the seventh character for the injury or poisoning code to identify subsequent care.
For example, when the lacrosse player with a broken leg is seen for a cast change, coders would report S82.234D.
Coders need to remember they cannot look back at past documentation when assigning a code, Avery says. If the physician does not specify that the lacrosse player is being seen for a nondisplaced oblique fracture of right tibia, coders may need to report S82.201D (unspecified fracture of shaft of right tibia).
External cause seventh characters
Many of the codes in Chapter 20 require a seventh character and coders again have three choices: A, D, S.
Remember that assignment of the seventh character for the external cause should match the seventh character of the code assigned for the associated injury or condition for the encounter, Leon-Chisen says.
Generally, a place of occurrence code (category Y92) is assigned only once, at the initial encounter for treatment. However, in the rare instance that a new injury occurs during hospitalization, an additional place of occurrence code may be assigned. No seventh characters are used for Y92.
Email your questions to Senior Managing Editor Michelle A. Leppert, CPC, at mleppert@hcpro.com