S21.301A: Unspecified open wound of right front wall of thorax with penetration into thoracic cavity, initial encounter

S21.301A, unspecified open wound of right front wall of thorax with penetration into thoracic cavity, initial encounter, is listed as a covered diagnosis in 3 Medicare billing and coding articles that apply to 18 HCPCS Level II codes, including G0238 (Therapeutic procedures to improve respiratory function…), G0237 (Therapeutic procedures to increase strength or endurance…), G0239 (Therapeutic procedures to improve respiratory function or…). The articles come from 1 Medicare contractor. 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 S21.301A as a covered diagnosis

CodeDescriptionMedicare coverageDMEPOS fee 2026 (state range)Articles listing it
G0238Therapeutic procedures to improve respiratory function, other than described by g0237, one on one, face to face, per 15 minutes (includes monitoring)Carrier judgment—1
G0237Therapeutic procedures to increase strength or endurance of respiratory muscles, face to face, one on one, each 15 minutes (includes monitoring)Carrier judgment—1
G0239Therapeutic procedures to improve respiratory function or increase strength or endurance of respiratory muscles, two or more individuals (includes monitoring)Carrier judgment—1
J0461Injection, atropine sulfate, 0.01 mgSpecial coverage instructions apply—1
J0153Injection, adenosine, 1 mg (not to be used to report any adenosine phosphate compounds)Special coverage instructions apply—1
J1250Injection, dobutamine hydrochloride, per 250 mgSpecial coverage instructions apply—1
J0280Injection, aminophyllin, up to 250 mgSpecial coverage instructions apply—1
J1245Injection, dipyridamole, per 10 mgSpecial coverage instructions apply—1
A9700Supply of injectable contrast material for use in echocardiography, per studySpecial coverage instructions apply—1
G0008Administration of influenza virus vaccineCarrier judgment—1
G0009Administration of pneumococcal vaccineCarrier judgment—1
G0010Administration of hepatitis b vaccineCarrier judgment—1
Q2038Influenza virus vaccine, split virus, when administered to individuals 3 years of age and older, for intramuscular use (fluzone)Special coverage instructions apply—1
Q2035Influenza virus vaccine, split virus, when administered to individuals 3 years of age and older, for intramuscular use (afluria)Special coverage instructions apply—1
Q2037Influenza virus vaccine, split virus, when administered to individuals 3 years of age and older, for intramuscular use (fluvirin)Special coverage instructions apply—1
Q2034Influenza virus vaccine, split virus, for intramuscular use (agriflu)Special coverage instructions apply—1
Q2036Influenza virus vaccine, split virus, when administered to individuals 3 years of age and older, for intramuscular use (flulaval)Special coverage instructions apply—1
Q2039Influenza virus vaccine, not otherwise specifiedSpecial coverage instructions apply—1

Medicare policy articles listing S21.301A

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 S21 diagnoses (Open wound of thorax)

Frequently asked questions

Does Medicare cover S21.301A (Unspecified open wound of right front wall of thorax with…)?

Medicare covers items and services, not diagnoses. 3 Medicare billing and coding articles list S21.301A as a covered diagnosis for 18 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 S21.301A?

The Level II codes from the policies most specific to this diagnosis are G0238 (Therapeutic procedures to improve respiratory function…, 1 article); G0237 (Therapeutic procedures to increase strength or endurance…, 1 article); G0239 (Therapeutic procedures to improve respiratory function or…, 1 article); J0461 (Injection, atropine sulfate, 0.01 mg, 1 article); J0153 (Injection, adenosine, 1 mg (not to be used to report any…, 1 article). Code choice depends on the item supplied; check each code's descriptor.

Which Medicare policy articles list S21.301A?

A56717 (Billing and Coding: Respiratory Therapy (Respiratory Care)); A56625 (Billing and Coding: Echocardiography); A54767 (Billing and Coding: Medicare Preventive Coverage for Certain Vaccines).

What is ICD-10-CM code S21.301A?

S21.301A is the ICD-10-CM code for unspecified open wound of right front wall of thorax with penetration into thoracic cavity, initial encounter, in category S21 (Open wound of thorax), chapter 19: Injury, poisoning and other consequences of external causes.

Next steps

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 19: Injury, poisoning and other consequences of external causes · All diagnoses · HCPCS lookup