L5: Service group

Classify CPT codes into service groups with group-specific documentation requirements, modifier rules, and global periods

Layer 5 classifies a CPT code into its service group — E/M, surgical, radiology, pathology, anesthesia, or DME. Each group has fundamentally different billing rules, documentation requirements, and modifier behavior.

How classification works

The resolver uses the CPT code prefix to determine the service group:

CPT prefix	Service group	Example codes
992xx-994xx	Evaluation & Management	99213, 99284, 99232
10000-69999	Surgical Procedures	27447, 43239, 29881
70000-79999	Radiology & Imaging	71046, 74177, 77067
80000-89999	Pathology & Laboratory	80053, 85025, 88305
90000-99199	Medicine	90471, 96372, 93000
00100-01999	Anesthesia	00142, 01402, 01967
A-L codes	Durable Medical Equipment	E0601, L3000, A4253

Request

curl "https://api-dev.rcintell.com/v1/knowledge/layers/170001/l5?cpt=99213" \
  -H "X-API-Key: $RCI_API_KEY"

L5 requires a cpt parameter. Without it, the layer cannot determine the service group and returns a note indicating it was skipped.

Response

{
  "layer": "l5_service_group",
  "data": {
    "service_group_key": "em",
    "name": "Evaluation & Management",
    "cpt_range": "99202-99499",
    "documentation": "Medical decision-making (MDM) or total time",
    "key_modifiers": [
      "25 (significant, separately identifiable E/M)",
      "57 (decision for surgery)"
    ],
    "split_shared_rules": true,
    "teaching_physician_rules": true
  }
}

Service group rules

Each group has unique billing characteristics that affect reimbursement:

E/M (99202-99499)

Documented by medical decision-making complexity or total time. Split/shared visit rules and teaching physician rules apply. Key modifier: 25.

Surgical (10000-69999)

Requires operative report. Global periods of 0, 10, or 90 days include follow-up visits. Multiple procedure reduction (MPPR) at 50% on secondary procedures.

Radiology (70000-79999)

Component billing: modifier 26 (professional) and TC (technical). Requires order with clinical indication.

Anesthesia (00100-01999)

Payment = (Base units + Time units + Modifying units) × Conversion factor. Requires anesthesia record with start/stop times.

Key modifiers by group

Group	Modifier	Description
E/M	25	Significant, separately identifiable E/M on same day as procedure
E/M	57	Decision for surgery — E/M that leads to major surgery
Surgical	50	Bilateral procedure
Surgical	51	Multiple procedures (triggers MPPR)
Surgical	59	Distinct procedural service
Surgical	78	Unplanned return to OR during global period
Surgical	79	Unrelated procedure during postoperative period
Radiology	26	Professional component only
Radiology	TC	Technical component only
Anesthesia	AA	Anesthesiologist personally performed
Anesthesia	QK	CRNA under medical direction
Anesthesia	QZ	CRNA without medical direction

Global periods

Surgical procedures include a post-operative global period during which follow-up visits are bundled into the surgical payment:

Global period	Meaning	Example
0 days	Only the procedure day is included	Minor procedures, endoscopies
10 days	10-day post-op follow-up included	Minor surgical (skin lesion removal)
90 days	1-day pre-op + 90-day post-op included	Major surgery (27447 total knee)
XXX	Global concept does not apply	E/M visits, lab, radiology

Billing an E/M visit during a surgical global period without modifier 24 (unrelated E/M during postop) or 79 (unrelated procedure) will result in denial. Check the global period from L5/L6 before billing post-operative visits.

Documentation requirements

Group	Required documentation
E/M	Medical decision-making (MDM) level or total time documentation
Surgical	Operative report with procedure details
Radiology	Order with clinical indication; interpretation report
Pathology	Order with medical necessity; CLIA certification
Anesthesia	Anesthesia record with start/stop times, medications, monitoring
DME	Certificate of Medical Necessity (CMN) for qualifying items