GA Modifier
HCPCS modifier indicating an Advance Beneficiary Notice of Non-coverage (ABN) was issued and is on file.
1 min read · Last reviewed May 23, 2026
At a glance
- Category
- Denials & Appeals
- Primary sources
- 1
- Workspace handoff
- ask d3 →
Where this comes up
This is denial-workbench territory. A remit posts with a CARC/RARC, the biller decides whether to rebill, appeal, or write off, and the appeal packet has to cite the chart, the order, and the payer's own policy language. Recurring patterns trace back to an upstream workflow gap.
Full definition
What it is in practice
CMS requires modifier GA on claim lines for services anticipated to be denied as not reasonable and necessary when a signed ABN is on file. Patient responsibility transfers when the claim denies.
How it shows up in your practice
Pair GA with proper ABN documentation. Audit GA frequency to ensure ABNs are issued only when truly needed — over-issuing can be a fraud and abuse signal.
Sources
- CMS — Advance Beneficiary Notice of Non-coverage (ABN)https://www.cms.gov/medicare/billing/abns
Verify GA modifier usage in Ask D3
Open ask d3 →Related terms
- Denials & AppealsABN (Advance Beneficiary Notice of Non-coverage)A standardized notice (CMS-R-131) given to Medicare fee-for-service beneficiaries before furnishing a service Medicare may not cover.
- Denials & AppealsGZ ModifierHCPCS modifier indicating an ABN was not issued for a service Medicare is expected to deny as not reasonable and necessary.
- PayerLCD (Local Coverage Determination)A MAC-published decision about whether a service is reasonable and necessary in its jurisdiction.
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.
Related across the archive
- GlossaryGZ ModifierHCPCS modifier indicating an ABN was not issued for a service Medicare is expected to deny as not reasonable and necessary.
- GlossaryABN (Advance Beneficiary Notice of Non-coverage)A standardized notice (CMS-R-131) given to Medicare fee-for-service beneficiaries before furnishing a service Medicare may not cover.
- GlossaryLCD (Local Coverage Determination)A MAC-published decision about whether a service is reasonable and necessary in its jurisdiction.
- GlossaryPR-204 (Non-Covered Service)Patient Responsibility 204 — patient is responsible for amounts the plan does not cover, often when an ABN or similar notice is on file.
- BillingHow to Appeal an Insurance Denial: Step-by-Step GuideClaim denied? Step-by-step appeal process with payer deadlines, denial code fixes, appeal letter template, and escalation options.
- BillingMedical Billing Denial Codes: What They Mean and How to Fix ThemCO-4, CO-97, CO-16, PR-96 and more. What each denial code means and exactly how to fix it.
- GlossaryModifier 22CPT modifier indicating increased procedural services requiring substantially greater work than usually required.
- GlossaryModifier 24CPT modifier indicating an unrelated E/M service performed by the same provider during a postoperative global period.
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.