A4218 — Sterile saline or water, metered dose dispenser, 10 ml
A4218 is a HCPCS Level II code for sterile saline or water, metered dose dispenser, 10 ml. It belongs to the Transportation, Medical & Surgical Supplies, Administrative section. Whether Medicare pays it depends on the coverage rule below.
Medicare coverage: Special coverage instructions apply
There are published conditions attached to this code. Check the applicable coverage policy before billing it: the code being valid is not the same as the service being covered.
From the coverage field of the CMS Alpha-Numeric HCPCS File, release 2026Q3-Jul. This states Medicare’s position on the code, not on your particular claim.
Physician fee schedule statusX
Statutory exclusion. The item or service is not within the statutory definition of 'physician services', so the fee schedule never pays it.
Global period: XXX
Want the dollar amount for your locality? The fee calculator applies your GPCI and the current conversion factor.
Medically Unlikely Edits — units per day
The most units of A4218 Medicare will pay on one date of service. Bill more on a single line and it is denied. The limit is not the same in every setting, so the row that matters is the one matching the claim you are building.
- practitioner
- 0 — never payable MAI 3 — Date of Service Edit: Clinical · CMS Policy
- outpatient
- 20 units MAI 3 — Date of Service Edit: Clinical · Clinical: CMS Workgroup
- DME supplier
- 56 units MAI 3 — Date of Service Edit: Clinical · CMS Policy
The adjudication indicator decides whether exceeding the limit is worth appealing at all: MAI 1 is a line edit you can support with documentation, MAI 3 is a date-of-service edit that is also appealable, and MAI 2 is absolute — no documentation overrides it. CMS MUE 2026Q3.
The CMS record for A4218
- Long descriptor
- Sterile saline or water, metered dose dispenser, 10 ml
- Short descriptor
- Sterile saline or water
- Added
- January 1, 2006
- BETOS
- O1E
- Pricing indicator
- 51 — Other
The official wording. This is what the code means.
CMS's 28-character form, which is what shows up on a remittance advice.
When CMS introduced the code.
Berenson-Eggers Type of Service — CMS's own analytic grouping.
Drugs.
Codes adjacent to A4218
HCPCS has no hierarchy — related items simply sit next to each other in the numbering. If A4218 is not quite right, the correct code is very often within a few positions of it.
- A4209Syringe with needle, sterile 5 cc or greater, each
- A4210Needle-free injection device, each
- A4211Supplies for self-administered injections
- A4212Non-coring needle or stylet with or without catheter
- A4213Syringe, sterile, 20 cc or greater, each
- A4215Needle, sterile, any size, each
- A4216Sterile water, saline and/or dextrose, diluent/flush, 10 ml
- A4217Sterile water/saline, 500 ml
- A4220Refill kit for implantable infusion pump
- A4221Supplies for maintenance of non-insulin drug infusion catheter, per week (list drugs separately)
- A4222Infusion supplies for external drug infusion pump, per cassette or bag (list drugs separately)
- A4223Infusion supplies not used with external infusion pump, per cassette or bag (list drugs separately)
- A4224Supplies for maintenance of insulin infusion catheter, per week
- A4225Supplies for external insulin infusion pump, syringe type cartridge, sterile, each
- A4226Supplies for maintenance of insulin infusion pump with dosage rate adjustment using therapeutic continuous glucose sensing, per week
- A4230Infusion set for external insulin pump, non needle cannula type
Questions about A4218
What is HCPCS code A4218?
A4218 is a HCPCS Level II code for sterile saline or water, metered dose dispenser, 10 ml. It sits in the Transportation, Medical & Surgical Supplies, Administrative section.
Does Medicare cover A4218?
The CMS HCPCS file marks A4218 as "Special coverage instructions apply". There are published conditions attached to this code. Check the applicable coverage policy before billing it: the code being valid is not the same as the service being covered.
How is A4218 paid under the physician fee schedule?
A4218 carries PFS status code X. Statutory exclusion. The item or service is not within the statutory definition of 'physician services', so the fee schedule never pays it.