M1399 HCPCS Level II code: Patients who leave the practice during the follow-up period
M1399 is the HCPCS code for “Patients who leave the practice during the follow-up period” in CMS’s October 2026 release, in effect from Oct 1, 2026.
Official description
M1399Patients who leave the practice during the follow-up period
Short description: Pt lve prac
HCPCS · United States
Medicare details
The indicators CMS publishes with M1399 in its October 2026 file. They describe Medicare’s handling, not another payer’s.
- Medicare coverage
- Carrier judgment
- Medicare pricing
- Service not separately priced by Part B (e.g., services not covered, bundled, used by Part A only, etc.)
- Type of service
- Medical care
- BETOS category
- Undefined codes
- Added
- Jan 1, 2025
Where M1399 sits
- 1M codesMedical services and quality measures
- 2Active code M1399Patients who leave the practice during the follow-up period
Source and release
- Data release
- HCPCS Level II · October 2026
- Effective date
- Oct 1, 2026
- Publisher
- CMS
This page is built from the HCPCS Level II catalog that Vero Codes reads when it suggests codes: Centers for Medicare & Medicaid Services’s October 2026 release, imported from the publisher’s file and checked against it. The description, notes and structured data come from the same record.
Frequently asked questions
What does HCPCS code M1399 mean?
M1399 is the HCPCS code for “Patients who leave the practice during the follow-up period” in CMS’s HCPCS Level II October 2026 release.
Does Medicare cover M1399?
CMS lists M1399’s Medicare coverage as “Carrier judgment” and its pricing as “Service not separately priced by Part B (e.g., services not covered, bundled, used by Part A only, etc.)”. Coverage and payment still depend on the patient, the setting, the documentation and the payer.
Which HCPCS Level II release does this page use?
It uses CMS’s October 2026 release, in effect from Oct 1, 2026 to Dec 31, 2026. It is a reference: confirm the code against the current list and the payer’s rules before you submit it.
Codes beside M1399
All M codesM1393Patients who were not diagnosed with recurrent melanoma during the current performance periodM1394Stages i-iii breast cancerM1395Patients receiving an initial chemotherapy regimen with a defined duration with the eligible clinician or groupM1396Patients on a therapeutic clinical trialM1397Patients with recurrence/disease progressionM1398Patients with baseline and follow-up promis surveys documented in the medical recordM1400Patients who died during the follow-up periodM1401Stages i-iii breast cancerM1402Patients receiving an initial chemotherapy regimen with a defined duration with the eligible clinician or groupM1403Patients with baseline and follow-up promis surveys documented in the medical recordM1404Patients on a therapeutic clinical trialM1405Patients with recurrence/disease progression