Billing

Modifier 73 / 74 (ASC Discontinued Procedure)

HCPCS modifiers indicating an ambulatory surgery center procedure was discontinued before (73) or after (74) anesthesia administration.

1 min read · Last reviewed May 23, 2026

At a glance

Category
Billing
Primary sources
1
Workspace handoff
ask d3

Where this comes up

This shows up in revenue-cycle work — claim scrubbing, charge entry, posting, A/R follow-up, and month-end close. Billers and practice managers hit this term when reconciling a payment, working a denial queue, or auditing why a claim aged past 60 days.

Full definition

What it is in practice

CMS defines 73 for discontinuation before anesthesia (50% payment) and 74 for after (full payment to the ASC). Used only in ASC settings.

How it shows up in your practice

Use the correct modifier based on whether anesthesia was started. Mis-use distorts ASC payment significantly.

Sources

Take it into the workspace

Confirm modifier 73/74 use in Ask D3

Open ask d3
Authored by D3rx

D3rx is a healthcare-billing and compliance research aid maintained by D3rx Inc. Articles are drafted by an LLM (Anthropic Claude) against primary HHS, OCR, CMS, eCFR, NIST, and state-regulator publications, and reviewed for restraint and source fidelity by the D3rx team.

Reviewer status: a named credentialed reviewer (CHC, CHPC, or healthcare attorney) is being engaged. Until that engagement is finalized, this page does not claim credentialed review.

This glossary entry is a research aid for billing and compliance staff. It does not provide legal, medical, or financial advice and does not replace counsel. References cited link to primary sources at HHS, OCR, CMS, eCFR, NIST, and the relevant payer or industry body.