E66.2: Morbid (severe) obesity with alveolar hypoventilation
E66.2, morbid (severe) obesity with alveolar hypoventilation, is listed as a covered diagnosis in 4 Medicare billing and coding articles that apply to 9 HCPCS Level II codes, including G0399 (Home sleep test (hst) with type iii portable monitor…), G0400 (Home sleep test (hst) with type iv portable monitor…), G0398 (Home sleep study test (hst) with type ii portable monitor…). The articles come from 4 Medicare contractors. A listed diagnosis supports medical necessity only; coverage still depends on the LCD's criteria and on documentation in the medical record.
HCPCS Level II codes with E66.2 as a covered diagnosis
| Code | Description | Medicare coverage | DMEPOS fee 2026 (state range) | Articles listing it |
|---|---|---|---|---|
| G0399 | Home sleep test (hst) with type iii portable monitor, unattended; minimum of 4 channels: 2 respiratory movement/airflow, 1 ecg/heart rate and 1 oxygen saturation | Carrier judgment | — | 1 |
| G0400 | Home sleep test (hst) with type iv portable monitor, unattended; minimum of 3 channels | Carrier judgment | — | 1 |
| G0398 | Home sleep study test (hst) with type ii portable monitor, unattended; minimum of 7 channels: eeg, eog, emg, ecg/heart rate, airflow, respiratory effort and oxygen saturation | Carrier judgment | — | 1 |
| G0238 | Therapeutic procedures to improve respiratory function, other than described by g0237, one on one, face to face, per 15 minutes (includes monitoring) | Carrier judgment | — | 2 |
| G0237 | Therapeutic procedures to increase strength or endurance of respiratory muscles, face to face, one on one, each 15 minutes (includes monitoring) | Carrier judgment | — | 2 |
| G0239 | Therapeutic procedures to improve respiratory function or increase strength or endurance of respiratory muscles, two or more individuals (includes monitoring) | Carrier judgment | — | 2 |
| C8925 | Transesophageal echocardiography (tee) with contrast, or without contrast followed by with contrast, real time with image documentation (2d) (with or without m-mode recording); including probe placement, image acquisition, interpretation and report | Special coverage instructions apply | — | 1 |
| C8926 | Transesophageal echocardiography (tee) with contrast, or without contrast followed by with contrast, for congenital cardiac anomalies; including probe placement, image acquisition, interpretation and report | Special coverage instructions apply | — | 1 |
| C8927 | Transesophageal echocardiography (tee) with contrast, or without contrast followed by with contrast, for monitoring purposes, including probe placement, real time 2-dimensional image acquisition and interpretation leading to ongoing (continuous) assessment of (dynamically changing) cardiac pumping function and to therapeutic measures on an immediate time basis | Special coverage instructions apply | — | 1 |
Medicare policy articles listing E66.2
- A56923: Billing and Coding: Outpatient Sleep Studies (Novitas Solutions, Inc. (MAC - Part A, MAC - Part B); 3 Level II codes). LCD with the same title: L35050
- A57179: Billing and Coding: Transesophageal Echocardiogram (First Coast Service Options, Inc. (MAC - Part A, MAC - Part B); 3 Level II codes). LCD with the same title: L33756
- A56717: Billing and Coding: Respiratory Therapy (Respiratory Care) (Palmetto GBA (MAC - Part A); 3 Level II codes). LCD with the same title: L34430
- A57224: Billing and Coding: Respiratory Care (Noridian Healthcare Solutions, LLC (MAC - Part A, MAC - Part B); 3 Level II codes). LCD with the same title: L34149
A diagnosis listed as covered in a billing and coding article supports medical necessity for the article's codes; it does not guarantee payment. Coverage depends on the LCD's criteria, the contractor's jurisdiction and documentation in the medical record.
Other E66 diagnoses (Overweight and obesity)
- E66.01 — Morbid (severe) obesity due to excess calories
Frequently asked questions
Does Medicare cover E66.2 (Morbid (severe) obesity with alveolar hypoventilation)?
Medicare covers items and services, not diagnoses. 4 Medicare billing and coding articles list E66.2 as a covered diagnosis for 9 HCPCS Level II codes: the diagnosis can support medical necessity for those codes, but payment still depends on the LCD's coverage criteria and the medical record.
Which HCPCS codes can be billed with ICD-10 E66.2?
The Level II codes from the policies most specific to this diagnosis are G0399 (Home sleep test (hst) with type iii portable monitor…, 1 article); G0400 (Home sleep test (hst) with type iv portable monitor…, 1 article); G0398 (Home sleep study test (hst) with type ii portable monitor…, 1 article); G0238 (Therapeutic procedures to improve respiratory function…, 2 articles); G0237 (Therapeutic procedures to increase strength or endurance…, 2 articles). Code choice depends on the item supplied; check each code's descriptor.
Which Medicare policy articles list E66.2?
A56923 (Billing and Coding: Outpatient Sleep Studies); A57179 (Billing and Coding: Transesophageal Echocardiogram); A56717 (Billing and Coding: Respiratory Therapy (Respiratory Care)), and 1 more article.
What is ICD-10-CM code E66.2?
E66.2 is the ICD-10-CM code for morbid (severe) obesity with alveolar hypoventilation, in category E66 (Overweight and obesity), chapter 4: Endocrine, nutritional and metabolic diseases.
Next steps
- Run a reimbursement report for a device billed under G0399
- Watch G0399 for fee, coverage and descriptor changes
- Build a full Medicare revenue model for G0399
Sources: CMS Medicare Coverage Database billing and coding articles (covered ICD-10 code lists and HCPCS links); ICD-10-CM FY2026; CMS HCPCS Level II release October 2026; CMS DMEPOS fee schedule 2026 (non-rural state fees). Not billing or legal advice.
Chapter 4: Endocrine, nutritional and metabolic diseases · All diagnoses · HCPCS lookup