Internal Medicine Billing & Coding Guide
High-acuity adult ambulatory care, level 4 and 5 E/M, MDM-driven coding under the 2021 office visit revision.
Common Internal Medicine CPT Codes
Ranked by claim frequency, with current MPFS work RVUs and global periods.
| Code | Description | Work RVU | Total RVU | Global |
|---|---|---|---|---|
| 99214 | Office o/p est mod 30 min | 1.92 | 4.06 | XXX |
| 99215 | Office o/p est hi 40 min | 2.80 | 5.76 | XXX |
| 99213 | Office o/p est low 20 min | 1.30 | 2.85 | XXX |
| 99490 | Chrnc care mgmt staff 1st 20 | 1.00 | 1.98 | XXX |
| 99491 | Chrnc care mgmt phys 1st 30 | 1.50 | 2.67 | XXX |
| 99439 | Chrnc care mgmt staf ea addl | 0.70 | 1.51 | ZZZ |
| 99457 | Rpm tx mgmt 1st 20 min | 0.61 | 1.55 | XXX |
| 99458 | Rpm tx mgmt ea addl 20 min | 0.61 | 1.24 | ZZZ |
| 99495 | Transj care mgmt mod f2f 14d | 2.78 | 6.59 | XXX |
| 99496 | Transj care mgmt high f2f 7d | 3.79 | 8.94 | XXX |
| 99497 | Advncd care plan 30 min | 1.50 | 2.60 | XXX |
| 99498 | Advncd care plan addl 30 min | 1.40 | 2.34 | ZZZ |
| 99406 | Behav chng smoking 3-10 min | 0.24 | 0.46 | XXX |
| 99407 | Behav chng smoking > 10 min | 0.50 | 0.87 | XXX |
| 96127 | Brief emotional/behav assmt | 0.00 | 0.15 | XXX |
| 36415 | Coll venous bld venipuncture | 0.00 | 0.00 | XXX |
| 99211 | Off/op est may x req phy/qhp | 0.18 | 0.73 | XXX |
What Internal Medicine practices are leaving on the table
High-value services that consistently get under-billed across the specialty. Each one is rooted in current 2026 fee schedule and policy updates.
Chronic Care Management (99490/99491) — $42-74/patient/month. Average internal medicine practice with 500 Medicare patients leaves $250K+/year on the table. Requires: patient consent, 20+ min/month of care coordination time.
Remote Patient Monitoring (99457/99458) — $50-100/patient/month for chronic conditions. Works alongside CCM. Requires: FDA-cleared device, 16+ days of data per 30-day period, 20+ min review time.
Annual Wellness Visits (G0438/G0439) — $175-250 per visit, zero patient cost-share. Only 50% of eligible Medicare patients get one. Proactive scheduling can add $100K+/year.
Transitional Care Management (99495/99496) — $168-238 per discharge follow-up. Must contact patient within 2 business days of discharge. Most practices miss this because they don't track hospital discharges.
Advance Care Planning (99497/99498) — $80-115 per session. Can be billed with AWV. No prior auth needed. Medicare covers this annually.
E/M level optimization — 30-40% of internal medicine practices undercode. Moving just 10% of 99213s to properly documented 99214s = $39/visit increase = $78K/year for 2,000 visits.
Code pairs that auto-bundle to CO-97
From the National Correct Coding Initiative for Internal Medicine. The rationale tells you when a modifier legitimately bypasses the edit and when it cannot.
Never bill two E/M levels on the same date for the same provider — pick the highest supported level
CCM codes are mutually exclusive in the same month — 99490 is staff-led (20 min), 99491 is physician-led (30 min)
99458 is add-on to 99457 — cannot bill 99458 without 99457 base code
G0438 is initial AWV (Welcome to Medicare), G0439 is subsequent — never bill both
TCM codes are mutually exclusive — 99495 is 14-day follow-up, 99496 is 7-day follow-up
Modifier Guidance for Internal Medicine
When each modifier legitimately applies in this specialty, with denial-pattern context and audit-defense documentation.
Required on E/M when billing with same-day procedure (36415, 96372, etc). Documentation MUST show a separately identifiable problem beyond the procedure.
Synchronous telemedicine — real-time audio/video. Place of Service 02 or 10. Must have established patient relationship for most payers.
Legacy telemedicine modifier — most payers now accept POS 02/10 without GT, but some Medicaid plans still require it.
Catastrophe/disaster — used during PHE declarations. Check if still active.
Documentation requirements
What needs to live in the encounter note for these codes to survive a payer audit.
- E/M (99213-99215): Document medical decision-making (MDM) level — number of problems, data reviewed, risk. Time-based coding requires TOTAL time on date of encounter documented.
- CCM (99490): Document 20+ minutes of clinical staff time, care plan, patient consent, and what was done (medication reconciliation, care coordination calls, etc).
- AWV (G0438/G0439): Requires Health Risk Assessment (HRA), cognitive screening, functional assessment, fall risk, depression screening (PHQ-2/9), and personalized prevention plan.
- TCM (99495/99496): Document discharge communication within 2 business days AND face-to-face visit within 7 or 14 days. Must be billed within 30 days of discharge.
OIG and audit triggers in Internal Medicine
Patterns that show up in OIG Work Plans, RAC audits, and CERT improper payment reviews. Build internal compliance checks around these.
Undercoding E/M: Billing 99213 when chart supports 99214. The 2021 MDM guidelines made 99214 easier to reach — moderate complexity only requires 2 of 3 MDM elements.
Missing modifier 25: Every E/M + same-day procedure needs it. Without it, the E/M gets denied or bundled. OIG audits show 42% of modifier 25 claims fail.
CCM time not tracked: Staff must log actual time spent on care coordination. 'I worked on the patient's chart' is not enough — document specific activities.
AWV billed as problem-oriented: If the patient brings up a new complaint during AWV, you CAN bill both G0439 + 99214 with modifier 25 — but the E/M documentation must be separate.
TCM missed window: Must contact patient within 2 business days of discharge. If you miss this, you cannot bill TCM. Set up automated discharge notifications from local hospitals.
Tobacco cessation not billed: 99406 (3-10 min) and 99407 (>10 min) are separately billable with E/M. Medicare covers 8 sessions/year with no cost-share.
Payer-specific billing notes
Where the major payers diverge from generic Medicare rules in Internal Medicine.
ME Medicare +
AWV (G0438/G0439) is fully covered with no patient cost-share. CCM requires patient consent documented in chart. TCM requires discharge communication within 2 business days.
UN UnitedHealthcare +
Strict on E/M frequency — may deny >4 visits/month without peer-to-peer. CCM requires UHC-specific consent form in some states.
AE Aetna +
Requires modifier 25 documentation to explicitly state 'separately identifiable' — vague notes get denied. CCM generally follows Medicare rules.
BC BCBS +
Varies by state plan. BCBS FL is strict on AWV coding. BCBS TX requires referral for some specialists. BCBS IL covers CCM but requires enrollment notification.
CI Cigna +
Prior auth required for high-frequency E/M (>2x/week). Accepts RPM codes but reimbursement is 60-70% of Medicare.
Standard Internal Medicine coding workflow
1. Check patient's active problem list → determines MDM complexity. 2. Count data reviewed (labs, imaging, records from other providers). 3. Assess risk level (prescription drug management = moderate). 4. Select E/M level based on 2 of 3 MDM elements. 5. If same-day procedure, add modifier 25 and document separate E/M. 6. Check if CCM/RPM/TCM applies. 7. Verify ICD-10 codes support the E/M level — lead with highest-complexity diagnosis.
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on May 31, 2026.
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