Timely filing · fee-for-service (HFS)
Illinois Medicaid timely filing limit
Short answer
The Illinois Medicaid timely filing limit is 180 days from the date of service, and HFS applies it to resubmitted claims as well as first submissions. For hospital inpatient claims the 180 days start on the discharge date. Medicare crossovers and Medicare-denied claims get two years from the date of service, and a claim with another primary payer is due within 180 days after that payer's final adjudication.
HFS dates receipt by the Julian date in the document control number (DCN). A paid claim can be replaced or voided within 12 months of the original paid voucher date. Compare other payers in the timely filing limits table.
Last reviewed by the Remitwright billing team. Editorial policy
The windows
- Initial claim
- 180 days from the date of service; for hospital inpatient claims, 180 days from the date of discharge1
- Counted from
- The date of service, or the discharge date for hospital inpatient claims, to the date HFS receives the claim. The first seven digits of the DCN are the Julian date of receipt. When another payer is primary, the 180 days run from that payer's final adjudication.
- Appeal
- HFS pays a rejected service only on a corrected claim that reaches it within 180 days of the date of service or within an exception period, and an override request that fails the criteria shows as a timely filing rejection on the remittance advice. A paid claim can be replaced or voided within 12 months of the original paid voucher date.
- Corrected claim
- A rejected service is paid only when every error is fixed and the corrected claim reaches HFS within 180 days of the date of service, or within the period of a qualifying exception. Replacements (claim frequency 7) and voids (frequency 8) of paid claims are due within 12 months of the original paid voucher date, and after a void the new original claim must arrive within 90 days of the void DCN.
- Verified
- , against the payer document in the sources
Your participation agreement can set a different window. Where the contract and the manual disagree, the contract applies.
A visit on Monday, March 2, 2026
Counting 180 days forward from a date of service of Monday, March 2, 2026 gives Saturday, August 29, 2026. That is the last day to file under the first limit shown above; a claim filed after it is outside the window unless one of the exceptions below applies.
Exceptions the payer allows
Medicare crossovers and Medicare denials
Claims Medicare paid and claims Medicare denied both have two years from the date of service. HFS treats a Medicare Advantage plan the same way when it is primary. For a Medicare denial, attach the EOMB showing the HIPAA denial reason and remark codes and an HFS 1624 Override Request stating why the override is needed.
Another payer was billed first
With third party liability, the claim is due within 180 days after the primary payer's final adjudication. Complete the TPL fields and HFS computes timeliness from the TPL adjudication date, so no override request is needed. If the primary payer later recoups, you get 180 days from the date of its recoupment notification letter, with the letter and an HFS 1624 attached.
Retroactive eligibility
When eligibility is added after the visit, the 180 days run from the date the Department's system was updated, which you can see in MEDI. Check eligibility for the date of service itself, not today's date or a date range, and attach an HFS 1624 to the claim.
Provider file changes
New enrollment, re-enrollment, a new specialty or category of service, or an added alternate payee starts a fresh 180 days on the date the change was recorded on the provider file. It covers only claims that could not be billed until the change was made, and the override must be requested within 180 days of the claim rejecting for that discrepancy.
Department errors, split bills and approvals
When an HFS or intermediary error stopped a claim from being received or adjudicated, the 180 days start when you are notified of the error. Split bills get 180 days from the date on the HFS 2432 spenddown form, and services needing prior or post approval get 180 days from the approval date.
What counts as proof of timely filing
- The DCN HFS assigns to the claim, whose first seven digits are the Julian date HFS received it
- For Medicare-denied claims, the EOMB showing the HIPAA denial reason and remark codes, sent with the HFS 1624 Override Request
- For third party liability claims, the completed TPL fields, from which HFS calculates timeliness off the TPL adjudication date
- For a split bill, the HFS 2432 Split Billing Transmittal/Spenddown Form attached with the HFS 1624
- For a primary payer recoupment, a copy of the recoupment notification letter attached with the HFS 1624
Notes for billers
- The 180-day deadline comes from Public Act 097-0689 and applies to claims with dates of service on or after July 1, 2012.
- HFS stopped accepting paper claims and attachments for anything received on or after December 15, 2021. Override requests go in as electronic attachments through MEDI, or through the Attachment Upload Portal when you bill outside MEDI.
- A provider operated by a unit of local government with a population over 3,000,000 gets 12 months from the date of service when local funds finance the federal share. Local education agencies get 18 months.
- Resubmit only when a claim has not shown up in MEDI 30 days after you sent it. A resubmission is held to the same 180 days as the original.
- When HFS decides an override request does not meet the exception criteria, the claim is still processed so its receipt is on record, and the remittance advice shows the timely filing rejection. Questions about a refused override go to a billing consultant at 877-782-5565.
- Replacement and void transactions correct errors on paid claims, such as a wrong provider number, date of service or procedure code. They do not apply to denied claims and cannot be used to add services.
FAQ
Questions about Illinois Medicaid deadlines
What is the Illinois Medicaid timely filing limit?
How long do I have for a Medicare crossover claim in Illinois?
Can I correct a paid Illinois Medicaid claim after the 180 days?
The patient's Medicaid eligibility was added after the visit. What is my deadline?
Can I wait for a workers' compensation or accident settlement before billing HFS?
What if the patient joined a managed care plan during a hospital stay?
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