Skip to content
HCC Buddy home

J43.1 ICD-10-CM Code: Panlobular emphysema

J43.1 maps to CMS-HCC V28 280 (RAF 0.319). Documentation must support MEAT. MEAT criteria · RAF calculator · free HCC coding tools

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

FY 2026 Apr update / Diseases of the respiratory system (J00-J99) / Chronic lower respiratory diseases (J40-J4A)

J43.1

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Panlobular emphysema

A type of emphysema where the air-filled spaces destroy the entire lung structure uniformly throughout both lungs, leading to progressive breathing difficulty.

Buddy the Bee presenting code insight

Buddy Insight

Panlobular emphysema involves destruction of the entire acinus (respiratory bronchiole, alveolar ducts, and alveoli) and predominantly affects the lower lobes.

CMS-HCC V28

HCC 280

RAF 0.319

CMS-HCC V24

HCC 111

RAF 0.335

ACA/HHS

HCC 160

Varies by metal level

ESRD/PACE

HCC 111

RAF 0.058

RXHCC

HCC 229

RAF 0.237

Code Book Path

Official
J43Emphysema
J43.1Panlobular emphysema

Inclusion Terms

Official
  • Panacinar emphysema

Excludes 2

Official
  • emphysema due to inhalation of chemicals, gases, fumes or vapors (J68.4)
  • emphysema with chronic (obstructive) bronchitis (J44.-)
  • emphysematous (obstructive) bronchitis (J44.-)
  • traumatic subcutaneous emphysema (T79.7)

Related Child Codes

Official
J43.0Unilateral pulmonary emphysema [MacLeod's syndrome]
J43.2Centrilobular emphysema
J43.8Other emphysema
J43.9Emphysema, unspecified

Includes

Official

ICD-10-CM does not list Includes notes for J43.1 in this effective period.

Excludes 1

Official
  • compensatory emphysema (J98.3)
  • interstitial emphysema (J98.2)
  • mediastinal emphysema (J98.2)
  • neonatal interstitial emphysema (P25.0)
  • surgical (subcutaneous) emphysema (T81.82)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for J43.1 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for J43.1 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for J43.1 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance
CT imaging demonstrating panlobular (panacinar) pattern of emphysema, typically lower-lobe predominant
Pulmonary function testing showing obstructive pattern with reduced diffusion capacity
Alpha-1 antitrypsin level testing and results if clinically indicated
Severity assessment including oxygen requirements and functional limitations

MEAT Support

HCC Buddy guidance
CT imaging demonstrating panlobular (panacinar) pattern of emphysema, typically lower-lobe predominant
Pulmonary function testing showing obstructive pattern with reduced diffusion capacity
Alpha-1 antitrypsin level testing and results if clinically indicated
Severity assessment including oxygen requirements and functional limitations

Audit Caution

HCC Buddy guidance
Failing to code alpha-1 antitrypsin deficiency (E88.01) as an additional diagnosis when it is the underlying cause
Confusing panlobular (lower-lobe predominant) with centrilobular (upper-lobe predominant) emphysema patterns
Using unspecified emphysema (J43.9) when CT imaging clearly describes the panlobular pattern
Not querying the provider when imaging describes lower-lobe predominant emphysema without specifying the type

Common Mistakes

HCC Buddy guidance
J43.2 — Centrilobular emphysema: affects only the central part of the acinus, upper-lobe predominant, typically smoking-related
J43.0 — Unilateral pulmonary emphysema (MacLeod's syndrome): unilateral condition, different etiology
J43.9 — Emphysema, unspecified: use only when the type of emphysema is not specified in documentation
E88.01 — Alpha-1 antitrypsin deficiency: code additionally when this underlying cause is documented

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is J43.1 an HCC code?

Yes. J43.1 (Panlobular emphysema) maps to Chronic Obstructive Pulmonary Disease, Interstitial Lung Disorders, and Other Chronic Lung Disorders under the CMS-HCC V28 risk adjustment model (and Chronic Obstructive Pulmonary Disease under V24), with a community non-dual aged RAF of 0.319. It is billable for payment year 2026.

Coder answer: J43.1 is billable and maps to V28 HCC 280, Chronic Obstructive Pulmonary Disease, Interstitial Lung Disorders, and Other Chronic Lung Disorders. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code
J43.1
Description
Panlobular emphysema
HCC (V28)
HCC 280 — Chronic Obstructive Pulmonary Disease, Interstitial Lung Disorders, and Other Chronic Lung Disorders
RAF
0.319
Billable
Yes
Payment year
2026

HCC Category Mapping

V28HCC 280, Chronic Obstructive Pulmonary Disease, Interstitial Lung Disorders, and Other Chronic Lung Disorders
0.319
V24HCC 111, Chronic Obstructive Pulmonary Disease
0.335
ESRDHCC 111, Chronic Obstructive Pulmonary Disease
0.058
RxHCCHCC 229, COPD and Chronic Bronchitis
0.237

Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

Work J43.1 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for J43.1

For J43.1 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

  • MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
  • EEvaluate: test results, medication response, or physical findings reviewed by the provider
  • AAssess: explicit mention in the assessment or plan with acknowledgment of status
  • TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed J43.1 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

Get the V28 RAF + MEAT cheat sheet

One printable page: confirm a code's V28 HCC status, its RAF weight, and the MEAT your note needs to make it stick. Free, no card.

Free PDF. No card. Unsubscribe anytime.

What This Code Means

J43.1 is the ICD-10-CM diagnosis code for panlobular emphysema. A type of emphysema where the air-filled spaces destroy the entire lung structure uniformly throughout both lungs, leading to progressive breathing difficulty. J43.1 sits in the ICD-10-CM chapter for diseases of the respiratory system (j00-j99), within the section covering chronic lower respiratory diseases (j40-j4a).

Under the CMS-HCC V28 risk adjustment model, J43.1 maps to Chronic Obstructive Pulmonary Disease, Interstitial Lung Disorders, and Other Chronic Lung Disorders (HCC 280) with a community, non-dual, aged base RAF weight of 0.319. Under the older CMS-HCC V24 model, J43.1 maps to Chronic Obstructive Pulmonary Disease (HCC 111) with a community, non-dual, aged base RAF weight of 0.335. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.

Panlobular emphysema, a specific subtype typically associated with alpha-1 antitrypsin deficiency. Provider documentation, pulmonology reports, or CT scan reads describing panlobular distribution support the code. Because J43.1 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for J43.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

  • •Panlobular emphysema, a specific subtype typically associated with alpha-1 antitrypsin deficiency. Provider documentation, pulmonology reports, or CT scan reads describing panlobular distribution support the code.
  • •Do not assign J43.1 without documentation of the panlobular subtype. Most emphysema in older Medicare populations is centrilobular (J43.2) or unspecified (J43.9).
  • •V28 HCC 280 at RAF 0.319.

Clinical Significance

Panlobular emphysema involves destruction of the entire acinus (respiratory bronchiole, alveolar ducts, and alveoli) and predominantly affects the lower lobes. It is classically associated with alpha-1 antitrypsin deficiency and represents a more diffuse and often more severe form of emphysema that significantly impacts respiratory function and patient outcomes.

Documentation Requirements

  • ✓CT imaging demonstrating panlobular (panacinar) pattern of emphysema, typically lower-lobe predominant
  • ✓Pulmonary function testing showing obstructive pattern with reduced diffusion capacity
  • ✓Alpha-1 antitrypsin level testing and results if clinically indicated
  • ✓Severity assessment including oxygen requirements and functional limitations
  • ✓Treatment plan including bronchodilators, pulmonary rehabilitation, and alpha-1 antitrypsin augmentation therapy if applicable
  • ✓Smoking history and cessation status

Commonly Confused Codes

  • •J43.2: Centrilobular emphysema: affects only the central part of the acinus, upper-lobe predominant, typically smoking-related
  • •J43.0: Unilateral pulmonary emphysema (MacLeod's syndrome): unilateral condition, different etiology
  • •J43.9: Emphysema, unspecified: use only when the type of emphysema is not specified in documentation
  • •E88.01: Alpha-1 antitrypsin deficiency: code additionally when this underlying cause is documented

Child Codes

J43.0Unilateral pulmonary emphysema [MacLeod's syndrome]
HCC 280
J43.1Panlobular emphysema
HCC 280
J43.2Centrilobular emphysema
HCC 280
J43.8Other emphysema
HCC 280
J43.9Emphysema, unspecified
HCC 280

Code Hierarchy

└J43Emphysema└J43.1Panlobular emphysema
└J43.1Panlobular emphysema

Because J43.1 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score.

J43.1 maps to CMS-HCC V28 category 280, Chronic Obstructive Pulmonary Disease, Interstitial Lung Disorders, and Other Chronic Lung Disorders. See the ICD-10 to HCC mapping hub for how the V28 crosswalk works. Because J43.1 carries a payment HCC, you can see what it adds to a RAF score and check the documentation the chart needs before it is submitted.

More on J43.1

Related condition guides

Referenced in blog posts

Work J43.1 in HCC Buddy

Open J43.1 in the Code Book for the full Index-to-Tabular path, MEAT checklist, and V28 HCC mapping, or in the Encoder to code from a keyword search. Pro includes 7 days to try everything, no card required.

Open in Code BookOpen in EncoderStart Pro