S21.309A: Unspecified open wound of unspecified front wall of thorax with penetration into thoracic cavity, initial encounter

S21.309A, unspecified open wound of unspecified 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 25 HCPCS Level II codes, including C8925 (Transesophageal echocardiography (tee) with contrast, or…), C8926 (Transesophageal echocardiography (tee) with contrast, or…), C8927 (Transesophageal echocardiography (tee) with contrast, or…). The articles come from 3 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 S21.309A as a covered diagnosis

CodeDescriptionMedicare coverageDMEPOS fee 2026 (state range)Articles listing it
C8925Transesophageal 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 reportSpecial coverage instructions apply—1
C8926Transesophageal echocardiography (tee) with contrast, or without contrast followed by with contrast, for congenital cardiac anomalies; including probe placement, image acquisition, interpretation and reportSpecial coverage instructions apply—1
C8927Transesophageal 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 basisSpecial coverage instructions apply—1
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
J2785Injection, regadenoson, 0.1 mgCarrier judgment—1
J0461Injection, atropine sulfate, 0.01 mgSpecial coverage instructions apply—1
J3490Unclassified drugsSpecial coverage instructions apply—1
J0153Injection, adenosine, 1 mg (not to be used to report any adenosine phosphate compounds)Special coverage instructions apply—1
Q9957Injection, perflutren lipid microspheres, per mlCarrier judgment—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
Q9956Injection, octafluoropropane microspheres, per mlCarrier judgment—1
C9399Unclassified drugs or biologicalsSpecial coverage instructions apply—1
A9700Supply of injectable contrast material for use in echocardiography, per studySpecial coverage instructions apply—1
C8921Transthoracic echocardiography with contrast, or without contrast followed by with contrast, for congenital cardiac anomalies; completeSpecial coverage instructions apply—1
C8922Transthoracic echocardiography with contrast, or without contrast followed by with contrast, for congenital cardiac anomalies; follow-up or limited studySpecial coverage instructions apply—1
C8923Transthoracic echocardiography with contrast, or without contrast followed by with contrast, real-time with image documentation (2d), includes m-mode recording, when performed, complete, without spectral or color doppler echocardiographySpecial coverage instructions apply—1
C8924Transthoracic echocardiography with contrast, or without contrast followed by with contrast, real-time with image documentation (2d), includes m-mode recording, when performed, follow-up or limited studySpecial coverage instructions apply—1
C8928Transthoracic echocardiography with contrast, or without contrast followed by with contrast, real-time with image documentation (2d), includes m-mode recording, when performed, during rest and cardiovascular stress test using treadmill, bicycle exercise and/or pharmacologically induced stress, with interpretation and reportSpecial coverage instructions apply—1
C8929Transthoracic echocardiography with contrast, or without contrast followed by with contrast, real-time with image documentation (2d), includes m-mode recording, when performed, complete, with spectral doppler echocardiography, and with color flow doppler echocardiographySpecial coverage instructions apply—1
C8930Transthoracic echocardiography, with contrast, or without contrast followed by with contrast, real-time with image documentation (2d), includes m-mode recording, when performed, during rest and cardiovascular stress test using treadmill, bicycle exercise and/or pharmacologically induced stress, with interpretation and report; including performance of continuous electrocardiographic monitoring, with physician supervisionSpecial coverage instructions apply—1
Q9955Injection, perflexane lipid microspheres, per mlCarrier judgment—1

Medicare policy articles listing S21.309A

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 S21.309A (Unspecified open wound of unspecified front wall of thorax…)?

Medicare covers items and services, not diagnoses. 3 Medicare billing and coding articles list S21.309A as a covered diagnosis for 25 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 S21.309A?

The Level II codes from the policies most specific to this diagnosis are C8925 (Transesophageal echocardiography (tee) with contrast, or…, 1 article); C8926 (Transesophageal echocardiography (tee) with contrast, or…, 1 article); C8927 (Transesophageal echocardiography (tee) with contrast, or…, 1 article); G0238 (Therapeutic procedures to improve respiratory function…, 1 article); G0237 (Therapeutic procedures to increase strength or endurance…, 1 article). Code choice depends on the item supplied; check each code's descriptor.

Which Medicare policy articles list S21.309A?

A57179 (Billing and Coding: Transesophageal Echocardiogram); A56717 (Billing and Coding: Respiratory Therapy (Respiratory Care)); A57306 (Billing and Coding: Transthoracic Echocardiography (TTE)).

What is ICD-10-CM code S21.309A?

S21.309A is the ICD-10-CM code for unspecified open wound of unspecified 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