What the CMS-1500 is
The CMS-1500 is the standardized federal health-insurance claim form that New York adopted for workers’ compensation medical billing and reporting. When your treating provider delivers care for a work injury, the CMS-1500 is the document that records what was done and bills the carrier for it. It is the routine, recurring report that builds the medical billing record of your case.
Because it is a federal form used across health care generally, the CMS-1500 carries familiar billing detail: the diagnosis codes, the procedure codes, the dates of service, and the provider’s information. In a comp case, that information also ties the treatment to the established work injury, which is why the form does double duty as both a bill and a treatment record.
The 2022 change
New York moved to the CMS-1500 in 2022, when it replaced the older C-4 billing forms that providers had used for medical billing. If you have an older case, you may still see references to the prior forms; for current treatment, the CMS-1500 is the billing document.
The shift was about consolidating billing onto a single federal form rather than the form-by-form C-4 set, so a provider’s office now reports treatment and bills the carrier through one familiar document instead of several.
The electronic mandate
The reporting also went fully electronic. Electronic submission of the CMS-1500 has been mandatory since August 1, 2025, meaning providers transmit the report rather than mailing paper.
For a patient, the practical effect is that your treatment reports should be reaching the case file faster and more reliably. You can confirm they are posting by checking eCase, which is where the electronic submissions appear once the carrier and Board receive them.
Why the C-4.3 still matters
One important point gets distorted easily. The CMS-1500 replaced the older C-4 billing forms, but it did not retire the entire C-4 family. The C-4.3, the Doctor’s Report of Maximum Medical Improvement and Permanent Impairment, is still a current New York form. It is not a billing form; it is the report a physician completes when a patient reaches maximum medical improvement (MMI) and the doctor is assessing any permanent impairment.
In practice, the C-4.3 is submitted together with the CMS-1500 when that stage of care arrives. So the accurate picture is not that the CMS-1500 swept the C-4 forms away, but that it took over the billing role while the C-4.3 continues to carry the permanent-impairment report. Knowing the difference helps you read your own case file correctly.
Reading your reports in the case file
Each CMS-1500 your provider files becomes part of the medical record the Board and carrier rely on. The diagnosis and procedure codes on those reports are what document, visit by visit, that your treatment connects to the work injury and what care you actually received. Gaps or inconsistencies in that running record are worth catching early, because the file is what the rest of the case is built on.
If you ever want to verify that a visit was reported, eCase is where the CMS-1500 submissions appear. Confirming that your treatment is showing up, and that a C-4.3 was filed when your doctor addressed MMI, is a reasonable thing for any patient to check.
A quick recap for your records
The short version is worth holding on to: the CMS-1500 is your provider’s current billing and treatment report, it became the standard in 2022, and its electronic submission has been required since August 2025. The C-4.3 sits beside it as the permanent-impairment report, not as something it replaced.
If you keep those two roles straight, the stream of paperwork in your file stops looking like clutter and starts reading as a record you can actually follow from one visit to the next.
What the form records
- Patient and provider details — who was treated and who treated them.
- Diagnosis codes (ICD) — the conditions being treated.
- Procedure codes (CPT/HCPCS) — what was actually done at the visit.
- Dates of service — when care was delivered.
- Charges — what the provider is billing the carrier.
Together those fields tie each visit to the established work injury, which is what makes the CMS-1500 both a bill and a treatment record.
CMS-1500 vs C-4.3 at a glance
- CMS-1500 — routine billing and treatment report, filed visit after visit (electronic since Aug 1, 2025).
- C-4.3 — the permanent-impairment report, filed once your doctor addresses maximum medical improvement. Not a billing form, and not replaced by the CMS-1500.
A quick check for your records
- After a visit, confirm the CMS-1500 posted to eCase.
- Check that diagnosis and procedure codes match the care you received.
- When your doctor addresses MMI, confirm a C-4.3 was filed.
- Flag any gap early — the billing record is what the rest of the case is built on.
This is general educational information about New York workers’ compensation medical reporting, not medical or legal advice. For questions about your own care or billing, check with your provider, the Workers’ Compensation Board, or a qualified attorney.