Cardiac and Pulmonary Rehab Billing 2026 (93797-93798, G0422-G0423, 94625-94626): Protect Every Session You Run

By Rcmaxis Revenue Cycle Team  ·  September 27, 2026  ·  11 min read

When OIG pulled 100 beneficiary-days of cardiac and pulmonary rehab from one provider, it couldn't confirm that Medicare's coverage requirements were met on a single one of them. The provider had been paid $2.7 million. OIG estimated that about $626 million paid to rehab providers nationwide during its audit period may not have met the requirements either.

That's the risk in cardiac rehab billing. The sessions are short, frequent and cheap one at a time, so nobody looks at them closely. Then an audit adds up two years of them. An intensive cardiac rehab series alone is worth $9,475 per patient at 2026 national rates (72 sessions at $131.60), and a program that bills the wrong number of sessions per day, or lets a treatment plan go unsigned, can lose a large share of that on review.

This guide covers the codes, the coverage rules, the time rules that decide how many sessions you can bill, and the documentation that has to exist every 30 days.

Cardiac Rehab Billing Codes and 2026 Medicare Rates

Rehab has three programs, each with its own codes and caps. The payment amounts below are 2026 national Medicare Physician Fee Schedule rates from CMS's October 2026 relative value file. Hospital outpatient departments bill the same codes but are paid for the facility portion under the OPPS, not these amounts.

The per-day limits in that table are CMS's October 2026 medically unlikely edits, and they line up with the coverage rules: two sessions a day for cardiac and pulmonary rehab, and up to six for intensive cardiac rehab.

Who Qualifies: Medicare Coverage Rules for Cardiac and Pulmonary Rehab

Coverage comes from two regulations, 42 CFR 410.49 for cardiac rehab and intensive cardiac rehab, and 42 CFR 410.47 for pulmonary rehab. The qualifying diagnosis has to be in the record before the first session.

Cardiac rehab and intensive cardiac rehab

• Acute myocardial infarction within the preceding 12 months
• Coronary artery bypass surgery
• Current stable angina
• Heart valve repair or replacement
• Coronary angioplasty or stenting
• Heart or heart-lung transplant
• Stable chronic heart failure: ejection fraction of 35 percent or less and NYHA class II to IV symptoms despite at least 6 weeks of optimal heart failure therapy

Pulmonary rehab

• Moderate to very severe COPD (GOLD II, III or IV), referred by the physician treating the chronic respiratory disease
• Confirmed or suspected COVID-19 with persistent symptoms, including respiratory dysfunction, for at least four weeks

The MI clock is the one that catches people. A patient referred 13 months after an infarction with no other qualifying event doesn't qualify on that basis, however sensible the referral looks clinically.

The Time and Session Rules That Decide Every Claim

This is where rehab revenue is won or lost. The Medicare Claims Processing Manual (Chapter 32) sets the time rules, and they're stricter than most programs' class schedules assume.

• 31 minutes makes a session. Under 31 minutes in a day, nothing is billable. From 31 to 60 minutes, it's one session.
• Two sessions need 91 minutes. For cardiac and pulmonary rehab, a second session on the same day requires at least 91 minutes of treatment in total. A 90-minute class is one session, not two.
• Minutes add across the day. 20 minutes in the morning and 35 in the afternoon is 55 minutes, which is one session.
• ICR works in hour steps. Each session beyond the first needs 31 or more minutes past the previous full hour, up to six sessions a day.

One series per qualifying event. A patient can't switch from cardiac rehab to intensive cardiac rehab. A patient who moves from ICR to regular cardiac rehab can reach up to 72 combined sessions at the contractor's discretion, with KX on the cardiac rehab sessions past 36.

Where Cardiac Rehab and Pulmonary Rehab Claims Get Denied

1. Billing two sessions for a 90-minute class. It's the most common error in the whole line, and it's an overpayment on every patient in the class. Build your schedule to 95 minutes if you intend to bill two sessions, and document actual start and stop times.

2. Treatment plans that lapse. The individualized treatment plan has to be established, reviewed and signed by a physician every 30 days. Sessions delivered after day 30 without a signed review are the easiest findings an auditor can make.

3. Missing required components. Every cardiac rehab day needs physician-prescribed exercise, and the program has to include risk factor modification, a psychosocial assessment and an outcomes assessment at the start and end. Pulmonary rehab adds education on respiratory problem management. Programs that document exercise and nothing else fail the component test.

4. The wrong monitoring code. 93798 means continuous ECG monitoring happened in that session, and 94626 means continuous oximetry. If the flow sheet doesn't show it, bill the unmonitored code.

5. ICR from a site that isn't approved. Intensive cardiac rehab is limited to CMS-approved programs, and the site has to enroll as an ICR supplier. The Claims Processing Manual tells contractors to deny ICR claims from providers not enrolled under that specialty, with CARC 8.

6. Sessions past 36 without KX, or KX without the documentation. The KX modifier is an attestation. Adding it to session 37 without a documented reason for continued treatment turns a coverage question into a false attestation.

7. COPD without staging. Pulmonary rehab for COPD requires GOLD II to IV. If spirometry results or the stage aren't in the referral, the claim can't support coverage.

Supervision Rules for 2026, Including Virtual Direct Supervision

Every rehab setting needs a physician or nonphysician practitioner (PA, NP or clinical nurse specialist) immediately available and accessible for consultations and emergencies whenever the program is running. The supervising practitioner needs expertise in cardiac or respiratory pathophysiology and basic or advanced life support training. The medical director has to be a physician licensed in the state where the program runs.

The CY 2026 Physician Fee Schedule final rule made one big change permanent. Direct supervision can now be provided through real-time audio and video (not audio-only) for services that require it, and CMS specifically extended that to incident-to cardiac rehab, intensive cardiac rehab and pulmonary rehab. Separately, the Consolidated Appropriations Act, 2026 lets hospitals furnish cardiac, intensive cardiac and pulmonary rehab to outpatients in their homes by real-time audio and video through December 31, 2027.

Virtual supervision doesn't remove the rest of the rules. Document who supervised each session, how (in person or by audio-video), and that they were reachable the whole time.

Medicare Advantage and Commercial Authorization for Rehab: What to Do

Original Medicare doesn't require prior authorization for cardiac or pulmonary rehab. Many Medicare Advantage and commercial plans do, and they usually approve a set number of sessions for a set period. Treat it like this:

1. Request the full series up front. Send the qualifying event and its date, the referral, the diagnosis codes, the individualized treatment plan and the number of sessions you expect (36 for cardiac or pulmonary rehab, up to 72 for ICR).
2. Track two numbers, not one. Log sessions used against sessions approved, and the authorization end date. Whichever runs out first ends the coverage.
3. Ask for an extension at session 30, not session 36. Include the progress from the outcomes assessment and the reason more sessions are needed. A late extension request leaves you delivering sessions nobody's paying for.
4. If the plan denies, ask for the criteria used, request a peer-to-peer with the program's medical director, and appeal with the qualifying event, the outcomes data and the signed plans.

The Workflow Fix: A Session-Level Rehab Billing Routine

Step 1. Capture minutes per patient per day. Start and stop times for each patient, not for the class. The claim follows the patient's minutes.

Step 2. Let the minutes pick the units. 31 to 90 minutes is one session. 91 or more is two (for cardiac and pulmonary rehab). Build the math into the flow sheet so staff never round by feel.

Step 3. Put the plan date on the schedule. Flag every patient whose treatment plan review is due within five days. No signature, no session billed until it's fixed.

Step 4. Count sessions against the cap. Show the running session count on each claim line. At 30, check the authorization. At 36, decide on KX with the documentation in hand.

Step 5. Match the code to the monitoring. The flow sheet should show whether ECG or oximetry monitoring ran. The code follows the sheet.

Step 6. Audit five patients a month. Rebuild their session counts from the minutes and compare to what you billed. Send repeat denials to your denial management workflow.

Revenue Impact of Getting Rehab Billing Right

• Per-patient value. At 2026 national non-facility rates, a full 36-session cardiac rehab series billed with 93798 is about $938 in professional payment, a pulmonary rehab series with 94626 is about $3,932, and a 72-session ICR series is about $9,475.
• The 90-minute problem. Picture a class of 12 pulmonary rehab patients meeting three times a week for 90 minutes. Billing two sessions per day when only one qualifies creates about 36 overbilled sessions a week. At $109.22 each, that's roughly $3,900 a week in payments you'd have to repay.
• Missed extensions. Sessions delivered after an authorization lapses are usually written off. Catching the extension at session 30 protects the last 6 sessions of every series.
• Days in AR. Rehab claims should pay inside 30 days. Past 45 days usually means authorization or frequency edits are holding them.
• Clean claim rate. 95 percent or better is realistic once minutes, plan dates and session counts are checked before the claim goes out.

For related guides, see our cardiology billing guide, our pulmonology billing guide and our cardiology billing services.

OIG, RAC and MAC Audit Exposure for Rehab Programs

• OIG's 2021 audit. Report A-02-18-01026 (May 13, 2021) found that the selected provider's records didn't contain enough evidence to show coverage requirements were met for any of the 100 sampled beneficiary-days. OIG estimated $2.7 million in payments to that provider, and about $626 million nationwide, may not have met the requirements. CMS updated guidance in two manuals in March 2021 in response.
• A long history. OIG reviewed outpatient cardiac rehab at 34 hospitals back in 2005, focused on direct physician supervision and incident-to requirements. The supervision rules have moved since, but the focus on who was available and what the plan said hasn't.
• What reviewers look for. Unsigned or late treatment plans, two sessions billed for under 91 minutes, sessions past 36 without KX or without support for it, missing components, and qualifying events outside the coverage window.
• Lookback. RACs generally review up to three years of claims. The 60-day overpayment rule (42 CFR 401.305) requires you to report and return overpayments you identify, with a six-year lookback.
• What to do now. Pick ten patients from the last year. For each session date, pull the minutes, the plan in force and its signature date. If more than one or two sessions can't be supported, widen the review before an auditor does.

Frequently Asked Questions About Cardiac Rehab Billing

How long does a cardiac rehab session have to be to bill it?

At least 31 minutes. A session of 31 to 60 minutes is one session. To bill two sessions of cardiac or pulmonary rehab on the same day, the patient needs at least 91 minutes of treatment that day.

How many cardiac rehab sessions does Medicare cover?

Up to 36 one-hour sessions, a maximum of 2 per day, over up to 36 weeks. The MAC can approve up to 36 more over an extended period. Sessions past 36 are billed with the KX modifier, which attests that documentation supports the added sessions.

What is the difference between 93797 and 93798?

Both are physician or other qualified health care professional services for outpatient cardiac rehabilitation, per session. 93797 is without continuous ECG monitoring and 93798 is with continuous ECG monitoring.

Who can bill intensive cardiac rehab G0422 and G0423?

Only sites running a CMS-approved ICR program and enrolled as an ICR supplier. ICR claims from providers not enrolled under the ICR specialty are denied.

Which patients qualify for pulmonary rehab under Medicare?

Patients with moderate to very severe COPD (GOLD II to IV) referred by the physician treating their chronic respiratory disease, and patients with confirmed or suspected COVID-19 who have had persistent respiratory symptoms for at least four weeks.