Billing modifier · CMS claims manual

Modifier 52: a service significantly less than usual.

Modifier 52 reports a service significantly less than usually required, or a partly reduced, cancelled or discontinued procedure for which anesthesia was not planned. For surgeries, CMS requires a concise statement of how the service differs and an operative report; hospital outpatient and ASC claims for these services are paid at 50 percent.

Sources: CMS manuals · retrieved November 2, 2026Reference page · nothing is sent or stored

Modifier 52 at a glance

Modifier: 52: Reduced Services
Used on: Services significantly less than usual; reduced services with no planned anesthesia
Medicare rule: Operative report and statement required; OPPS and ASC pay 50% when discontinued without planned anesthesia
Primary source: CMS Ch. 12 s.40.2; Ch. 4 s.20.6.4; Ch. 14 s.40.4

What CMS says

CMS chapter 12, section 40.2.A.10 says surgeries for which services performed are significantly less than usually required may be billed with modifier 52. The biller must provide a concise statement about how the service differs from the usual and an operative report with the claim. Unlike modifier 22, which should only be reported with codes that have a global period of 0, 10 or 90 days, there is no such restriction on modifier 52.

Chapter 4 describes it for hospital outpatient departments as a partial reduction, cancellation or discontinuation of services for which anesthesia is not planned; it provides a means of reporting reduced services without disturbing the identification of the basic service.

How it is paid

Hospital OPPS: procedures for which anesthesia is not planned that are discontinued, partially reduced or cancelled after the patient is prepared and taken to the room are paid at 50 percent of the full OPPS payment amount.

ASC: beginning January 1, 2008, contractors apply a 50 percent payment reduction for discontinued radiology procedures and other procedures that do not require anesthesia, and services billed with modifier 52 or 73 are not subject to the multiple procedure discount.

Worked example with a hypothetical $1,200.00 OPPS payment rate: a qualifying discontinued procedure without planned anesthesia is paid at 50 percent, $600.00, before copayment and deductible.

Limits

CMS says elective cancellation of a procedure should not be reported. If anesthesia was planned or given, the facility modifiers are 73 and 74 instead. For physician services that were discontinued, see modifier 53. How a commercial payer pays a 52 line is set by its own policy and contract.

Look-alike modifiers

Modifier 53: Discontinued physician service.
Modifier 73: Facility procedure stopped before anesthesia.
Modifier 51: Additional procedures at one session.

The full modifier descriptions are in the AMA CPT code book and the HCPCS Level II code set; this page covers only what the CMS claims manuals say about modifier 52.

Sources

CMS: Medicare Claims Processing Manual, Chapter 12 (Rev. 13753, issued 05-07-26) — section 40.2.A.10, unusual circumstances (retrieved 2026-11-02)
CMS: Medicare Claims Processing Manual, Chapter 4 (Rev. 13799, issued 05-28-26) — section 20.6.4, modifiers 73 and 74 (describes 52 and 53) (retrieved 2026-11-02)
CMS: Medicare Claims Processing Manual, Chapter 14 (Rev. 13836, issued 06-24-26) — section 40.4, payment for terminated procedures (retrieved 2026-11-02)

Every rule above was read from these CMS pages on November 2, 2026. Payers revise policies and contracts, so confirm anything that affects a claim with the payer or your Medicare Administrative Contractor.

Frequently asked questions

What must accompany a modifier 52 surgical claim?

CMS says a concise statement of how the service differs from the usual and an operative report.

How does Medicare pay modifier 52 in the hospital outpatient setting?

At 50 percent of the full OPPS payment amount for procedures with no planned anesthesia that were discontinued, reduced or cancelled after the patient was prepared and taken to the room.

Is modifier 52 limited to codes with a global period?

No. CMS says the global period restriction applies to modifier 22, and there is no such restriction on modifier 52.

Not legal, billing or medical advice

This page explains published CMS manual text. It cannot see your claim, your contract or any payer’s policy. Confirm with the payer or your Medicare Administrative Contractor (MAC) before you bill, resubmit or appeal.