ICD-10 code I37.1: Nonrheumatic pulmonary valve insufficiency

Key Takeaways

ICD-10 Code I37.1 is a billable, specific diagnosis code for nonrheumatic pulmonary valve insufficiency, effective since October 1, 2015.

The code belongs to parent category I37 (Nonrheumatic pulmonary valve disorders) under ICD-10-CM Chapter IX, block I30-I5A.

Rheumatic origin and congenital pulmonary valve conditions are excluded from I37.1 and require separate codes (I09.89 and Q22.1-Q22.3 respectively).

Pabau’s claims management software helps cardiology and specialist practices submit I37.1 claims accurately and reduce denial rates.

ICD-10 Code I37.1 covers nonrheumatic pulmonary valve insufficiency, a condition in which the pulmonary valve fails to close completely during diastole, allowing blood to flow backward from the pulmonary artery into the right ventricle. It can be assigned as a principal or secondary diagnosis and has been billable since the first year of non-draft ICD-10-CM.

This condition is also referred to as pulmonary regurgitation in clinical documentation. It is distinct from stenosis (narrowing of the valve) and from conditions caused by rheumatic fever or congenital malformation. The nonrheumatic designation is the key qualifier that determines which ICD-10-CM code applies. Coders must confirm the etiology is explicitly documented before assigning I37.1.

Billable status and code hierarchy for I37.1

I37.1 is a fully billable, specific ICD-10-CM code. It can be used as a principal or secondary diagnosis on reimbursement claims with a date of service on or after October 1, 2015. According to the CDC/NCHS ICD-10-CM web tool, the code is listed in the valid billable set for FY2026 with no revisions.

Its parent code, I37, is a non-billable header. Coders should never assign I37 alone; the condition must be coded to one of its specific child codes:

• I37.0 – Nonrheumatic pulmonary valve stenosis
• I37.1 – Nonrheumatic pulmonary valve insufficiency (this code)
• I37.2 – Nonrheumatic pulmonary valve stenosis with insufficiency
• I37.8 – Other nonrheumatic pulmonary valve disorders
• I37.9 – Nonrheumatic pulmonary valve disorder, unspecified

Maintaining HIPAA-compliant clinical documentation throughout the coding workflow is essential when submitting claims that hinge on a specific pathophysiological etiology such as nonrheumatic origin. Any ambiguity in the provider’s notes can lead to a payer requesting further documentation or downgrading the claim to an unspecified code.

Excludes notes for ICD-10 code I37.1

The I37 category carries two Excludes1 notes that apply directly to I37.1. Misreading them is one of the most common causes of coding errors and subsequent claim denials in cardiology billing.

Excludes1: Rheumatic and congenital pulmonary valve conditions

An Excludes1 note means “not coded here” – the excluded condition is never coded alongside I37.1. The I37 category lists two:

• Pulmonary valve disorder specified as rheumatic (I09.89) – conditions that arose from rheumatic fever. If the provider documents rheumatic origin, I09.89 applies instead of I37.1.
• Pulmonary valve disorder specified as congenital (Q22.1, Q22.2, Q22.3) – malformations present at birth. Acquired, nonrheumatic insufficiency developing later in life does not belong in the Q22 series.

MS-DRG groupings for ICD-10 code I37.1

When I37.1 is submitted as the principal diagnosis on an inpatient claim, it groups into one of two Medicare Severity Diagnosis Related Groups (MS-DRGs) under v43.0. The grouping determines the base payment rate the facility receives.

MS-DRG 306 carries a significantly higher relative weight than MS-DRG 307, meaning the reimbursement difference between these two groups can be substantial. Coders and clinical documentation improvement (CDI) specialists should ensure that any qualifying complication or comorbidity present during the admission is captured and coded.

Common MCCs seen alongside I37.1 include acute right-sided heart failure and respiratory failure requiring mechanical ventilation. Accurate complication documentation is equally critical across every circulatory system chapter, because it directly drives DRG assignment.

Verify current grouping weights against the CMS ICD-10 codes page, which publishes updated MS-DRG tables each fiscal year. Reimbursement figures shift annually and the v43.0 grouper data above reflects the most recently confirmed values at time of publication.

Streamline cardiology claim submissions with Pabau

Pabau's claims management tools help specialist practices submit accurate diagnosis codes, attach supporting documentation, and reduce denials on complex cardiac cases like I37.1.

Book a demo

Clinical context: Causes and documentation of nonrheumatic pulmonary valve insufficiency

Pulmonary valve insufficiency diagnosed as nonrheumatic typically arises from one of several acquired mechanisms. Coders need this clinical background to accurately query providers when documentation is unclear, and to support patient care management workflows in cardiology settings.

Common causes of acquired nonrheumatic pulmonary insufficiency

• Infective endocarditis: bacterial infection of the valve leaflets leading to structural damage and regurgitation
• Pulmonary hypertension: chronically elevated pulmonary artery pressure that dilates the valve annulus and prevents adequate leaflet coaptation
• Post-surgical sequelae: insufficiency as a known complication following repair of tetralogy of Fallot or other right-sided cardiac surgeries (note: if the original defect was congenital, careful attention to coding sequelae vs the original congenital code is required)
• Carcinoid syndrome: fibrosis caused by serotonin-secreting tumors that affects right-sided valves, especially the pulmonary and tricuspid valves
• Trauma or iatrogenic injury: damage to the valve during cardiac catheterization or other procedures

Symptoms most commonly documented in the medical record include dyspnea on exertion, fatigue, and signs of right-sided heart failure such as peripheral edema and jugular venous distension. Echocardiography remains the primary diagnostic procedure used to confirm and grade the severity of insufficiency. Cardiac catheterization may be performed when hemodynamic assessment is required or when surgical intervention is being planned.

ICD-10 code I37.1 documentation requirements and coding tips

Insufficient or ambiguous documentation is the leading root cause of claim denials and audit risk for I37.1. The provider’s notes must explicitly support each element of the code before it is assigned. Practices that use digital clinical intake forms can build structured cardiology templates that prompt clinicians to document etiology, severity, and relevant history at the point of care.

What the medical record must establish

• Valve affected: the pulmonary valve specifically, not a general reference to “valvular disease”
• Type of dysfunction: insufficiency, regurgitation, or incompetence (these terms are synonymous and all support I37.1)
• Etiology: explicitly nonrheumatic. If the note says “pulmonary valve insufficiency” without specifying etiology, a coder query may be warranted
• Exclusion of congenital origin: the record should not reference a congenital valve malformation; if congenital history exists, review Q22.x codes

When comorbid conditions are present, coders should also assess which secondary diagnosis codes apply alongside I37.1. Right-sided heart failure (I50.81x), pulmonary hypertension (I27.x), and carcinoid syndrome (E34.0) are among the most commonly co-coded conditions. Each additional accurate secondary diagnosis may affect MS-DRG assignment and reimbursement.

Sequencing guidance

I37.1 may be coded as a principal diagnosis when it is the condition established after study to be chiefly responsible for the admission. It functions as a secondary diagnosis when the patient is admitted primarily for another condition but pulmonary valve insufficiency is clinically significant. The AAPC Codify ICD-10-CM lookup provides sequencing notes and cross-references that can help coders verify correct principal vs secondary placement.

Maintaining well-structured structured patient records makes it far easier to establish coding rationale during payer audits. When documentation is fragmented across visit notes, discharge summaries, and cardiology reports, coders spend significant time piecing together the clinical picture rather than focusing on accurate assignment.

Related codes and crosswalks

Understanding where I37.1 sits in relation to adjacent codes prevents miscoding and supports accurate DRG grouping. The table below shows the most clinically relevant sibling and crosswalk codes. The same hierarchical logic – a non-billable parent header above specific, billable child codes – applies throughout ICD-10-CM.

Verify current code descriptions and hierarchical relationships against the official ICD-10-CM tabular before assigning any adjacent code, since fiscal-year updates can revise descriptions and excludes notes. Building code-validation checks into clinical workflows reduces human error during assignment.

CPT and ICD-10-PCS codes commonly paired with I37.1

Diagnosis codes work alongside procedure codes. The following procedure codes are most commonly paired with an I37.1 diagnosis, though assignment depends on the specific services rendered and must be verified against the clinical record. For EHR integration for cardiology workflows, pairing diagnosis and procedure codes accurately within the same encounter is where most claims errors originate.

• 93306 – Echocardiography, transthoracic, real-time with image documentation; complete (most common diagnostic procedure used to assess and grade pulmonary regurgitation)
• 93307 – Echocardiography, transthoracic, real-time with image documentation; without spectral or color flow Doppler
• 93452 – Left heart catheterization, including crossing aortic valve (used for hemodynamic evaluation prior to surgical correction)
• 33478 – Outflow tract augmentation, with or without commissurotomy, infundibulectomy, or patch (pulmonary valve surgical intervention)
• 33477 – Transcatheter pulmonary valve implantation, percutaneous approach (used for eligible patients undergoing transcatheter valve replacement)

Always verify CPT code applicability against current AMA guidelines and payer-specific policies. Procedure codes not documented in the operative or procedure note should never be assigned.

Conclusion

Accurate assignment of ICD-10 Code I37.1 requires clear documentation of nonrheumatic etiology and careful review of excludes notes to rule out rheumatic and congenital origins. MS-DRG grouping, sequencing decisions, and paired procedure codes all depend on that foundation being in place at the point of clinical documentation.

Pabau’s claims management software helps cardiology and specialist practices structure their documentation workflows, attach supporting clinical records to submissions, and track claim outcomes across complex cardiac diagnoses. To see how Pabau handles cardiac coding workflows from intake to reimbursement, book a demo with the team.

Continue your research

Need a structured framework for clinical documentation compliance? Pabau’s compliance management tools help specialist practices document and audit clinical records against regulatory requirements.

Looking for cardiology-friendly patient record management? GP and specialist clinic software from Pabau supports structured referral workflows and multi-practitioner record access.

Want to reduce paperwork burden in cardiology intake? Medical forms in healthcare practice covers how practices are modernizing intake and consent documentation to support accurate coding.

Frequently asked questions