ICD-10: Understanding initial, subsequent and sequelae
October 21, 2015
Now that ICD-10-CM is finally here, you will need to familiarize yourself with new concepts such as initial, subsequent, and sequelae classifications for diagnosis codes. Most coders and auditors are familiar with the concepts of initial and subsequent from using E/M codes to describe hospital visits. The initial visit typically describes the first visit by the admitting physician (or the consultant when the payer doesn't recognize consultation codes).
As providers follow the patients during a hospital stay, those services are billed with subsequent encounter codes. When the patient is discharged, then admitted again to the hospital at a later date, the process of starting with an initial code, then switching to subsequent codes is repeated.
The ICD-10 coding system brings the concept of initial and subsequent to diagnosis coding of injuries and poisoning, although it's important to know that the terms are applied slightly differently. ICD-10-CM introduces a third concept, sequelae, which applies to conditions that occur after subsequent treatment and after the acute phase of a disease or injury..
The ICD-10-CM Official Guidelines define the initial encounter diagnosis coding as the one to use "while the patient is receiving active treatment for the condition." It goes on to say that this could be for surgical treatment, an emergency department encounter, or evaluation and treatment by a new physician.
An initial encounter is denoted in ICD-10-CM by the seventh character of A.
A subsequent encounter is defined as "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 cited include a cast change, removal of a fixation device, or medication adjustment. In these encounters, the seventh digit of the ICD-10-CM code is D.
Sequelae is used for the complications or conditions that arise as the direct result of a condition that is essentially considered to be otherwise resolved. For example, the guidelines cite the scar formation that occurs after a burn. In these cases, the first ICD-10-CM code used during the encounter is the reason for the visit.
In the example noted above, a patient being seen for the scar would have the scar listed as the first diagnosis code. The second code would be the sequelae code for the underlying cause, which is the burn itself. In this case, the code would end with the letter S.
Let's see how the ICD-10-CM coding would work with an actual burn example. The patient is being treated for burns to the left lower leg caused by scalding hot water that was being heated on the stove.
When the patient is treated in the emergency room, the doctor would code T24.032A
for the burn of unspecified degree of the left lower leg, T31.0 because the
burns occupied less than 10 percent of the body surface, and X12.XXXA for contact
with other hot fluids.
Here is where it gets confusing. If the patient is treated in the emergency room for comfort care, then follows up with another physician as an outpatient for active treatment, that second physician will continue to use the A for active encounter. The code selections would be the same.
If the patient receives treatment in the hospital, then follows up with the same physician as an outpatient, the physician would then use T24.032D for the burn and X12.XXXD for the contact with other hot fluids.
If the patient needed to have a surgical intervention to treat the burns, the A would continue to be used as the seventh character for the surgery because the burn would be considered to be under active treatment.
These codes would continue to be used for all visits during the routine follow-up treatment phase of the burn, regardless of the number of encounters.
Now, let's say the burns have healed and the patient now has a scar on the left leg and is being treated for the scar.
In this case, the primary diagnosis would be L90.5, for the scar condition of the skin. The burn code would now be considered a sequelae, so the second code would be T24.0032S to explain the reason for the scar.
It may take time, but you'll soon be comfortable enough with initial, subsequent, and sequelae to apply them routinely.
Early days: ICD-10 claims are a mixed bag so far It's still too early to draw any conclusions about the revenue cycle impact of ICD-10 implementation, but signs are mixed so far. Most practices are reporting that ICD-10 claims have been accepted without incident, while others are seeing claims rejected for a variety of reasons.
As this issue of The Business of Medicine went to press, only a handful of practices submitted ICD-10 claims quickly enough to have seen them paid. One orthopedic practice in Louisiana saw two claims with ICD-10 get paid, and the staff is already celebrating this minor success. More broadly, most of the impact so far has fallen on the providers and coders. Online, some of the most heavily broadcast "tweets" on the #ICD10 hashtag have come from providers and coders who have had to adjust their daily workflow to select correct diagnosis codes from the much larger list of available ICD-10 codes.
Scott Kraft, CPC, CPMA (firstname.lastname@example.org). The author is an Auditor and Consultant at DoctorsManagement.