Step 1: Select Base Injury or Enter Code

Popular Base Injury Diagnoses:

Or Type Any Base Diagnosis (3 to 6 characters):

Step 2: Choose Clinical Episode of Care (7th Character)

Character A: Initial Encounter (Closed)

Active treatment: surgical repair, emergency evaluation, cast application.

Character B: Initial Encounter (Open Type I/II)

Active treatment for Gustilo-Anderson open fracture grade I or II.

Character C: Initial Encounter (Open Type IIIA/B/C)

Active treatment for severe open fracture with extensive soft tissue damage.

Character D: Subsequent Encounter (Routine Healing)

Encounter during healing or recovery phase: cast change, medication adjustment, follow up.

Character G: Subsequent Encounter (Delayed Healing)

Recovery phase where bone union is progressing slower than medically expected.

Character K: Subsequent Encounter (Nonunion)

Failure of fractured bone ends to unite properly.

Character P: Subsequent Encounter (Malunion)

Fracture healed in an abnormal or deformed anatomical position.

Character S: Sequela (Late Effect)

Late complications, scars, or chronic pain arising after the acute injury has terminated.

Generated 7-Character Code 100% Billable Code

S52.521A

Displaced transverse fracture of shaft of right radius, initial encounter for closed fracture

7-Character Position Breakdown:

Official CMS Rules for Initial (A) vs. Subsequent (D) vs. Sequela (S)

Initial Encounter (Character A)

Used while the patient is receiving active treatment for the condition. Examples include surgical treatment, emergency department encounters, and evaluation and continuing treatment by the same or a different new physician. It is not limited to the first visit ever.

Subsequent Encounter (Character D)

Used for encounters after the patient has completed active treatment and is receiving routine care during the healing or recovery phase. Examples include cast removal or change, removal of external fixation device, medication adjustment, and follow up visits.

Sequela (Character S)

Used for complications or late conditions that arise as a direct consequence of an acute injury that has healed. Two codes are required: the specific manifestation code (e.g. scar or arthritis) is sequenced first, followed by the injury code with 7th character S.

Why the Placeholder 'X' Is Critical for Claim Acceptance

ICD-10-CM codes can contain between 3 and 7 characters. When a code category requires a 7th character for encounter reporting, but the category and subcategory only consist of 4 or 5 characters (such as T79.A0 - Compartment syndrome, unspecified), standard transaction processors will automatically reject any code where the 7th character is placed in position 5 or 6.

To satisfy HIPAA 5010 electronic claim format standards, coders must assign dummy placeholder 'X' characters to fill empty intermediate positions so that the encounter character sits strictly in slot 7: T79.A0XA.