NY Workers’ Comp Billing Guidelines and Medicaid Managed Care Rules for 2026

NY workers’ comp billing guidelines require electronic bills. Every provider must send the CMS-1500 and a medical narrative through a Board-approved submission partner within 120 days of treatment. Prior authorization now runs through OnBoard, not Form C-4AUTH. Medicaid managed care claims, however, follow each plan’s contract: a filing limit of at least 90 days and prompt-pay clocks of 30 or 45 days.

Two Rulebooks: Which New York Medical Billing Regulations Apply?

New York has no single medical billing code. Instead, workers’ comp and Medicaid managed care claims follow different laws, agencies and deadlines. So the first billing decision is always the same: which system owns this visit?

The Workers’ Compensation Board (WCB) enforces the Workers’ Compensation Law (WCL) and its rules in 12 NYCRR. Medicaid managed care, by contrast, runs on the Department of Health (DOH) plan contract, Insurance Law §3224-a and each plan’s provider manual.

Part 1: NY Workers’ Comp Billing Guidelines for 2026

This part covers eligibility, eBill, narratives and fee schedules.

Who Can Treat and Bill Injured Workers

Today, most clinicians need WCB authorization before they treat an injured worker (WCL §13-b). Authorized providers who bill in their own name include physicians, chiropractors, podiatrists, psychologists, nurse practitioners and physician assistants. Physical and occupational therapists, licensed clinical social workers and acupuncturists also qualify.

However, some clinicians must bill through a supervising provider:

• Physical therapy assistants: The supervising PT bills with modifier CQ, and payment is 85% of the PT fee.
• Occupational therapy assistants: The supervising OT bills with modifier CO, also at 85%.
• Residents and fellows: The supervising physician bills with modifier 1R at the regular fee. This billing rule took effect April 22, 2026.
• Residents assisting at surgery: The surgeon bills with modifier 84, and the assistant service pays 16% of the physician fee.

In addition, dentists, optometrists, audiologists, DME suppliers, pharmacies, emergency providers and out-of-state providers may submit bills.

This will change soon. From January 1, 2028, universal authorization lets every eligible licensed provider in good standing treat injured workers without separate Board approval. Even so, the Board will keep an exclusion list.

The eBill Mandate: Electronic CMS-1500 Through an Approved Partner

The CMS-1500 replaced 12 custom workers’ comp forms, such as the C-4.0, C-4.2 and PT-4/OT-4, in July 2022. Since August 1, 2025, every provider, regardless of office size, must also submit it through a Board-approved electronic submission partner (Subject Number 046-1707).

The workflow looks like this:

1. You send the bill and medical narrative to your submission partner in the format you agree on.
2. The partner then transmits them to the correct payer and sends a copy to the Board.
3. Next, the payer returns an electronic acknowledgment with the receipt date.
4. Finally, your partner forwards that acknowledgment to you. According to the Board, you also get confirmation of acceptance or rejection within seven days.

Also, do not mail, fax or email a duplicate paper form to the Board.

What if a paper bill slips through? For paper bills received on or after August 1, 2025, payers send an EOB with CARC 16 and RARC N34 instead of an objection form. To get paid, resubmit the bill electronically. However, the deadline is still 120 days from the date of care, so fix paper bills quickly.

In addition, you can offset partner costs with CPT 99080, at your actual cost up to $1.00, on the same CMS-1500. Since March 31, 2026, you may also file Form HP-1.0 when a payer pays the bill but not the offset.

The Medical Narrative That Makes a Bill Valid

Every CMS-1500 needs a medical narrative or attachment. The Board’s template puts three elements at the top: work status, causal relationship and temporary impairment percentage. If a required element is missing, the report may be legally defective.

Not every provider comments on all three, though. For example, PT, OT and acupuncture records do not count as evidence of causal relationship, and these providers do not rate impairment. So payers should not deny a bill only because those elements are absent.

Certain bills also need attachments:

• DME: The prescription and proof of NYS Medicaid enrollment, including the supplier’s MMIS number.
• Pharmacy: The invoice and the prescription.
• Radiology and laboratory: The invoice and the report.

Fee Schedules and the Pending 2026 Update

The WCB fee schedules cap payment for each service type. RefMed sells most of them, while the Dental and DME schedules are free on the Board’s website.

Two ground rules add 20% for eligible providers. Medical Ground Rule 17 (modifier 1D) covers providers with Board-assigned rating codes in family medicine, general practice and internal medicine. Similarly, Behavioral Health Ground Rule 18 (modifier 1B) covers designated behavioral health services.

A fee schedule update is pending. The Board first proposed updates to five schedules, including the Medical Fee Schedule, on January 14, 2026. It then published a revised proposal on September 2, 2026, which would significantly raise evaluation and management fees. As of October 30, 2026, however, the Board had not adopted it, so current schedules still apply.

C-4AUTH Is Retired: New York Prior Authorization Runs Through OnBoard

Many billers still search for the New York C-4AUTH prior authorization form, often spelled C4AUTH. However, the Board stopped accepting new C-4AUTH, MG-1 and MG-2 requests on May 2, 2022. Today, providers submit prior authorization requests (PARs) in OnBoard, inside the WCB Medical Portal. You can no longer fax, email or mail paper requests.

To get access, request a Board-assigned NY.gov user ID. Each provider and each delegate needs their own login.

When Treatment Needs No PAR

Care that follows the Medical Treatment Guidelines (MTGs) needs no prior authorization. The current MTGs apply to treatment on or after May 2, 2022. They cover the neck, back, shoulder, knee and other body parts, plus conditions such as non-acute pain.

Even so, some procedures need a PAR when they follow the MTGs. The Board’s MTG training lists 11 of them, including lumbar fusion, artificial disc replacement, spinal cord stimulators and knee arthroplasty. In addition, repeating a procedure after it fails needs a PAR.

PAR Types and Carrier Response Deadlines

A deadline that falls on a weekend or public holiday moves to the next business day (General Construction Law §25-a). Full rules sit on the Board’s OnBoard page for health care providers.

What Happens After a Late Answer or a Denial

If a carrier misses its deadline, the Board may issue an Order of the Chair. For PARs other than medication, a medical denial or partial grant goes straight to the carrier’s Level 2 physician reviewer. After that, you can ask the Board’s Medical Director’s Office (MDO) for a Level 3 review. Administrative denials, however, are not eligible for Level 3, except for medication PARs.

For MTG-related, DME and medication requests, the MDO decision is final on medical necessity. By contrast, any denial of a non-MTG request over $1,000 goes to a priority hearing.

One threshold change is now law. The 2026 state budget raises the WCL §13-a(5) authorization threshold from $1,000 to $1,500 on January 1, 2028, when universal authorization starts. Until then, the $1,000 threshold applies. Our prior and retro authorization services can also track these requests for your team.

NY Workers’ Comp Deadlines, Objections and Unpaid Bills

Under NY workers’ comp billing guidelines, two clocks control cash flow. First, your clock starts on the date of care. Then the payer’s clock starts when it receives the bill.

The 120-Day Billing Deadline

Under 12 NYCRR 325-1.25(b), you must submit a bill within 120 days of the date of care. For hospital outpatient bills, the 120 days run from the last day of care. Late bills, or bills in the wrong format, cannot receive an award from the Chair. Still, the Chair may excuse a late bill for good cause on written application.

The Payer’s 45-Day Pay-or-Object Rule

Within 45 days of receiving a bill, the payer must pay it or object (12 NYCRR 325-1.25(c) and WCL §13-g). For electronic bills, the 45 days run from the receipt date on the payer’s acknowledgment. If the payer disputes only part of a bill, it must still pay the undisputed part within 45 days.

Objections come in three types, and the payer must raise them all at once:

• Legal objections on Form C-8.1B, such as causation or missing authorization.
• Valuation objections on Form C-8.4, such as excessive billing or wrong coding.
• MTG objections, such as treatment that does not follow the guidelines.

Each objection also needs an EOB with matching CARC and RARC codes. Since January 5, 2026, payers must use the updated Form C-8.1B, and a few objections now need only an EOB. If a payer misses the 45 days, however, it owes the bill up to the fee schedule amount. The Board will not review late objections.

Filing an HP-1.0 for an Unpaid Bill

If 45 days pass without full payment or a timely objection, file Form HP-1.0 in OnBoard. The Board no longer accepts paper HP-1.0 forms, and it suggests waiting 60 days to allow for payment cycles. However, you cannot file while a timely legal objection on Form C-8.1B remains open.

The Board then takes one of two paths:

• Administrative award: This path applies when a Board-authorized provider got no timely C-8.4 valuation objection. The Board then sets the award from the fee schedule.
• Arbitration: This path applies when the payer filed a timely C-8.4. It also covers care outside New York and providers who cannot be Board-authorized, such as DME suppliers and pharmacies. Each side gets 30 days to send a 250-word rationale and up to 20 pages.

To support an HP-1.0, attach the CMS-1500 and narrative, proof of medical necessity and any C-8.4 or EOB. For example, an approved PAR or an MTG Lookup Tool summary shows necessity. For an administrative award, the Board considers only what you already filed. The Board’s unpaid medical bills page lists documents by scenario.

New York Claim Deadline Calculator

Part 2: NY Medicaid Managed Care Billing Challenges

When a Medicaid member belongs to a managed care plan, you usually bill the plan, not eMedNY. As a result, your deadlines, edits and appeal steps come from the plan contract, framed by state law. Watch for these five challenges.

Challenge 1: Sending the Claim to the Right Payer

First, confirm Medicaid eligibility and plan enrollment for the date of service. Then check whether the plan carves out the service.

Pharmacy is the biggest carve-out. NYRx, the NY Medicaid Pharmacy Program, took over on April 1, 2023. It now covers drugs for members of mainstream plans, Health and Recovery Plans (HARPs) and HIV Special Needs Plans. As a result, those pharmacy claims go to Medicaid fee-for-service, not the plan. Managed long term care plans and the Essential Plan were not part of that change.

Challenge 2: Timely Filing Limits That Differ by Plan

Medicaid fee-for-service claims are due within 90 days of the date of service, according to eMedNY’s General Billing guide. If a delay was outside your control, add a delay reason code. Also, if eMedNY denies a claim for missing or wrong data, correct and resubmit it within 60 days of the notice. In any case, claims must be payable within two years of the service date.

Managed care plans work differently. Under Insurance Law §3224-a, claims are due within 120 days of service unless the law or your contract sets other terms. For Medicaid managed care contracts, however, the parties may agree on a different period, but never less than 90 days. So check your participation agreement, not just the eMedNY rule.

Missed the limit? A participating provider may ask for reconsideration of a claim denied only as late. The provider must show an unusual occurrence and a pattern of timely filing. The plan may then cut payment by up to 25%. However, claims sent 365 or more days after service fall outside this rule. For other payers, see our guide to timely filing limits for medical claims.

Challenge 3: Prompt-Pay Clocks and Underpayment Follow-Up

Section 3224-a also sets payment clocks for managed care plans certified under Public Health Law Article 44. A plan must pay a clean claim within 30 days if it arrived electronically, or 45 days if it came on paper or by fax.

If payment is not reasonably clear, the plan must pay the undisputed part. It must also explain a denial or request missing information in writing within 30 calendar days of receipt. Once it decides it owes more, it has 15 days to pay. Late payments also earn interest at 12% a year or the corporate tax rate, whichever is greater.

Therefore, flag every electronic managed care claim that is still unpaid on day 31. Our denial management services team can also work plan denials and underpayments.

Challenge 4: Prior Authorization Clocks Changed in 2026

DOH’s service authorization timeframe comparison (revised June 2026) sets the plan clocks:

• Standard requests: A decision is due 3 business days after the plan has all needed information. Since April 1, 2026, the outer limit is 7 days from receipt, down from 14.
• Expedited requests: A decision is due within 72 hours of receipt.
• Retrospective review: A decision is due 30 days after the plan has all information.

For standard and expedited requests, the plan may extend the deadline by up to 14 days in some cases. So send complete clinical notes with the first request, because the 3-day clock starts only when the file is complete.

Challenge 5: Secondary Claims and Adjustment Codes

New York Medicaid pays last. Before billing it, bill every other payer, including workers’ comp, and keep the denial. If the primary payer returns a CARC, put that code on the Medicaid claim.

In its April 2026 Medicaid Update, DOH also warned providers never to change the primary payer’s group codes, such as CO to PR, on secondary claims. Any resulting overpayments are subject to recoupment.

Eligibility is also shifting. Under federal rules, some adults must meet a work requirement from January 1, 2027, so verify coverage at every visit.

2026 Changes New York Billing Teams Should Track

Several 2026 updates touch both sets of New York medical billing regulations at once. Use this table to set reminders for your team.

When a Patient Has Both Workers’ Comp and Medicaid

Start at intake. Ask every patient whether a work injury or illness led to the visit, and record the answer.

For work-related care, bill the workers’ comp carrier first through your submission partner. Meanwhile, bill unrelated care to the member’s plan as usual. If the workers’ comp payer denies a bill, keep the denial and its CARC. Medicaid needs that proof that you billed the other payer first.

Also, you generally may not bill the injured worker for workers’ comp care (WCL §13-f).

Before you submit a New York claim, confirm that:

• The visit belongs to the right system: workers’ comp, the managed care plan or fee-for-service.
• The treating provider holds WCB authorization, or bills through an authorized supervisor.
• An approved PAR is on file when the MTGs or the plan require one.
• The CMS-1500 and narrative go through a Board-approved electronic submission partner.
• The bill goes out within 120 days (workers’ comp) or within the plan’s contract limit (Medicaid managed care).
• Day 45 (workers’ comp) and day 30 (electronic managed care claims) are on your follow-up calendar.

Manage New York Workers’ Comp and Medicaid Claims With MedXpert Services

Workers’ comp eBill rules, OnBoard authorizations and managed care contracts each add their own deadlines. As a result, one missed step can leave a valid claim unpaid.

MedXpert Services supports New York practices with workers’ comp and Medicaid managed care billing. Explore our workers’ compensation billing services or learn more about our medical billing services in New York to discuss your practice’s needs.

If unpaid bills are building up, a review of your claim workflow can show where the delays start.