Medicare Timely Filing Limits for Claim Submission (2025 Guide)
Timely filing limits determine how long a healthcare provider has to submit a claim after a patient’s service date. For Medicare claims, these limits are strictly enforced. In 2025, the Centers for Medicare & Medicaid Services (CMS) continued to enforce the 12-month filing rule for all Medicare Part A and Part B claims. This means providers must ensure claims are received (not mailed) by their Medicare Administrative Contractor (MAC) within one calendar year of the Date of Service (DOS).
For example, a service performed on July 1, 2024 must reach the MAC by July 1, 2025. Institutional claims use the “Through” date, while professional claims use the “From” date as the anchor. Failing to meet this timeline triggers denial code CO 29 (“Time limit for filing claim”), which cannot be appealed through normal redetermination routes. However, certain exceptions — such as CMS error, retroactive eligibility, or natural disaster waivers — may allow a claim reopening if properly documented
Blog Outline
- What Is Medicare’s Timely Filing Limit? (2025 Overview)
- MAC / State Differences in Medicare Timely Filing (2025)
- Medicare vs. Medicare Advantage (MA) Filing Limits (2025)
- Denial Codes & Appeals Related to Timely Filing (Medicare 2025)
- Exceptions and Extensions to Timely Filing (Medicare 2025)
- Practical Workflow & Automation for Medicare Timely Filing Compliance (2025)
- Conclusion: Staying Ahead of Medicare’s Timely Filing Rules in 2025
- Frequently Asked Questions (Medicare Timely Filing 2025)
What Is Medicare’s Timely Filing Limit? (2025 Overview)
The Medicare timely filing limit defines how long providers have to submit a claim after the Date of Service (DOS). Under federal law, the standard timeframe remains 12 months (one full calendar year) from the date the service was rendered.
According to CMS regulation 42 CFR § 424.44,
“Medicare payment may not be made for services furnished unless the claim is filed within 1 calendar year after the date of service.”
That means if a claim for a service performed on July 1, 2024 isn’t received by Medicare by July 1, 2025, it will be automatically denied as untimely — regardless of mailing delays. The key date is the MAC’s receipt date, not the date you submit electronically or postmark your paper claim.
(Source: CMS Pub 100-04 Ch. 1 § 70)
Medicare’s 12-Month Filing Rule
| Type of Claim | Filing Limit | Anchor Date Used | Regulatory Source |
|---|---|---|---|
| Medicare Part A (Institutional) | 12 months (1 year) from DOS | “Through” date of the claim | CMS Pub 100-04 § 70 |
| Medicare Part B (Professional) | 12 months (1 year) from DOS | “From” date of service | 42 CFR 424.44 |
| Medicare Advantage (MA) Plans | Usually 90–180 days (varies by insurer) | “From” or “Discharge” date depending on plan | Wellcare Manual 2025 / UHC Provider Guide 2025 |
2025 Update — Adjustments No Longer Restricted by the 12-Month Rule
Until 2024, even claim adjustments had to comply with the same 12-month submission rule. However, in October 2024, CMS issued Change Request 12909, updating the Medicare Claims Processing Manual (Pub 100-04 Ch. 1 § 70.5) to state:
“There is no longer a timely filing period for adjustments.”
This change means that adjusted or corrected claims may now be submitted beyond the 12-month limit, provided they comply with standard reopening or change request provisions.
Exception: Adjustments that increase an inpatient PPS DRG must still be submitted within 60 days of the original claim’s remittance date. This 2025 update is significant because it reduces administrative denials related to post-adjudication corrections, helping providers recover legitimate underpayments more easily.
(Sources: CMS CR 12909 (Oct 2024); CMS Pub 100-04 § 70.5)
MAC / State Differences in Medicare Timely Filing (2025)
While the 12-month rule applies uniformly to all Medicare Part A and B claims, each Medicare Administrative Contractor (MAC) adds clarifications regarding anchor dates, exception handling, and resubmission policies.
In 2025, no MAC extends the filing limit beyond one year, but their local guidance helps providers avoid technical denials — especially when dealing with rejected, corrected, or reopened claims.
Below is a summary of the major MAC jurisdictions, their filing limits, and any state-specific nuances.
Medicare Administrative Contractors and Jurisdiction Rules (2025)
| MAC / Jurisdiction (States Covered) | Filing Limit (2025) | Anchor Date | Exceptions / Notes | Official Source (Updated) |
|---|---|---|---|---|
| Noridian (Jurisdictions E & F) — AK, AZ, CA, HI, ID, IA, KS, MN, MT, NE, ND, OR, SD, WA, WY | 12 months (1 year) from DOS | “From” date (Part B); “Through” date (Part A) | CMS exceptions apply; claims denied after 12 months require reopening (TOB xxQ). Feb 29 DOS → file by Feb 28 next year. | Noridian Timely Filing (Part A) (Updated June 2025) |
| CGS Administrators — AL, GA, TN, and DME B/C states | 12 months from DOS | “Through” date for span claims | Unprocessable (RTP) claims must be corrected & resubmitted within 12 months. Timely-filing denials not appealable as initial determinations. | CGS Timely Filing Requirements (2025) |
| Palmetto GBA — AL, GA, TN, NC, SC, VA | 12 months from DOS | Receipt date to MAC (processable claim) | Must fix rejected claims within 12 months. CMS exceptions per IOM Ch. 1 §70.7. Late denials ≠ appealable decisions. | Palmetto Claims Information |
| First Coast Service Options (FCSO) — FL, PR, USVI | 12 months from DOS | Part B: “From” date; Part A: “Through” date | Feb 29 → Feb 28 rule; EDI cutoff 6 PM ET; paper claims count on receipt date. Standard CMS exceptions only. | First Coast Claims FAQ (2024) |
| Novitas Solutions — AR, CO, LA, MS, NM, OK, TX; DE, DC, MD, NJ, PA | 12 months from DOS | “From” date (Part B); “Through” (Part A) | Follows CMS rules. FAQ confirms 1-year limit and CMS exceptions. | Novitas FAQ (Jul–Sep 2025) |
| National Government Services (NGS) — CT, NY, ME, MA, NH, RI, VT | 12 months from DOS | “From” or “Through” date as applicable | No local deviations identified. Standard CMS exceptions apply. | CMS Pub 100-04 §70 |
| WPS-GHA — IA, KS, MO, NE, IL, MN, WI | 12 months from DOS | “From” date (Part B); “Through” date (Part A) | No local deviation found. Follows national rule. | CMS Pub 100-04 §70 |
💡 Tip: When working across multiple MAC regions (e.g., large multi-state groups), always confirm local submission cutoffs and file dates through your MAC’s 2025 provider manual. This ensures compliance across all facilities and reduces avoidable denials.
Medicare vs. Medicare Advantage (MA) Filing Limits (2025)
While Original (Fee-for-Service) Medicare follows the strict 12-month filing rule set by CMS, Medicare Advantage (MA) plans—administered by private insurers such as UnitedHealthcare, Wellcare, Humana, Aetna, and Cigna—establish their own filing deadlines. These timelines are often much shorter, typically ranging from 90 to 180 days after the Date of Service (DOS).
1. Original Medicare (CMS)
🏛️
- Governed by federal regulation 42 CFR § 424.44 and the CMS Medicare Claims Processing Manual (Pub 100-04 Ch. 1 § 70).
- Filing limit: 12 months (1 calendar year) from the DOS.
- Anchor: “From” date for professional claims (Part B); “Through” date for institutional claims (Part A).
- Exceptions: Only those listed in CMS IOM § 70.7 (e.g., agency error, retroactive eligibility, natural disaster).
- Appeals: Untimely filing denials (CO 29) cannot be appealed; a “reopening” is required if an exception applies.
2. Medicare Advantage (MA) Plans
Medicare Advantage (MA) plans operate under contracts with CMS but set their own claim submission rules. These rules are not governed by the federal 12-month requirement. In practice, the major MA plans specify:
| MA Plan (Example) | Filing Limit (2025) | Anchor Date | Notes / Special Conditions (2025) | Source |
|---|---|---|---|---|
| Wellcare (Centene) | 180 calendar days from DOS (or discharge) | “From” date for professional; “Discharge” for facility | Applies to clean claims only; resubmissions must occur within 180 days of original service date. | Wellcare Provider Manual 2025 |
| UnitedHealthcare (UHC) | 90 to 180 days (depending on state or contract) | Date of service or discharge (as defined by contract) | Filing limits vary by state; providers should check their contract’s “Timely Filing Limit” section. | UHC Provider Guide 2025 |
| Aetna Medicare Advantage | 120 calendar days from DOS | Date of service for outpatient and professional claims | Resubmission window = same 120 days; no retroactive waivers allowed without CMS approval. | Aetna MA Provider Manual 2025 |
| Humana Medicare Advantage | 180 days from DOS | “From” date for Part B; “Discharge” for inpatient | May allow extensions for provider credentialing delays or retro eligibility if documentation provided. | Humana MA Provider Portal 2025 |
| Cigna MA | 120 days from DOS | “From” date for outpatient and professional claims | Follows state-specific rules if shorter limits exist under Medicaid integration plans. | Cigna MA Provider Manual 2025 |
3. Key Differences Between Original Medicare and MA Plans
| Category | Original Medicare (CMS) | Medicare Advantage (MA) |
|---|---|---|
| Governing Authority | CMS (Federal) | Individual insurer contract with CMS |
| Filing Limit | 12 months (1 year) from DOS | 90 – 180 days (typical) |
| Anchor Date | “From”/“Through” date | “From” or “Discharge” date (defined in plan) |
| Exceptions / Waivers | CMS IOM § 70.7 exceptions (e.g., error, retro eligibility) | Defined by each plan — may allow credentialing or retro enrollment exceptions |
| Appeal Rights | Late-filing denials not appealable (only reopening possible) | Follow plan’s internal appeal or grievance process (usually 60–120 days) |
| Best Practice | Track DOS and file within 12 months (verify MAC receipt) | Review each MA plan’s Provider Manual annually for current filing limits |
- Original Medicare (FFS) → 12 months from DOS.
- MA plans → 90–180 days, depending on contract.
- No universal MA rule — always verify the provider manual.
- Late claims to MA plans generally can’t be appealed through CMS.
- Automate tracking by plan to avoid avoidable denials
Denial Codes & Appeals Related to Timely Filing (Medicare 2025)
Timely filing denials are among the most common—and most preventable—causes of lost Medicare revenue. When a claim arrives at the Medicare Administrative Contractor (MAC) after the 12-month filing window, it is automatically denied as untimely, regardless of the reason for delay. Under CMS policy, late filing denials are not considered “initial determinations”—which means they cannot be appealed through the normal redetermination process. Instead, providers must pursue a claim reopening if a valid CMS exception applies. Read more on CO 29 and N39011 denials here
Exceptions and Extensions to Timely Filing (Medicare 2025)
While Medicare’s 12-month claim submission rule is firm, the Centers for Medicare & Medicaid Services (CMS) does allow limited exceptions in specific circumstances. These exceptions are described in the Medicare Claims Processing Manual (Pub. 100-04, Chapter 1, §70.7) and provide a path for reopening otherwise untimely claims. In all cases, the provider must prove that one of these conditions applies and submit supporting documentation when requesting a reopening or waiver.
CMS-Approved Exceptions (IOM 100-04 § 70.7)
| Exception Category | Description | Documentation Required | Example / Notes |
|---|---|---|---|
| 1. Administrative Error by CMS or a MAC | When the delay was due to a processing error or system failure caused by CMS or its contractor. | Written evidence of the error (e.g., MAC system outage notice, EDI rejection logs, CMS memo). | Example: CMS system downtime prevented claim acceptance during filing window. |
| 2. Retroactive Beneficiary Entitlement / Enrollment | When the patient’s Medicare eligibility or enrollment was made effective retroactively after the DOS. | Proof of retroactive entitlement (Medicare eligibility letter, SSA documentation). | Patient initially not eligible on DOS but later granted retro coverage. |
| 3. Retroactive Determination of Coverage | When CMS or a MAC reopens a previous denial and changes the coverage decision after the filing limit. | MAC reopening notice or CMS correspondence showing the correction. | Prior denial overturned, creating new filing opportunity. |
| 4. Administrative Appeals or Litigation Outcome | When a court, hearing officer, or CMS appeal results in retroactive coverage or payment authorization. | Copy of appeal or court decision letter. | Appeals extending beyond 12 months may re-enable claim submission. |
| 5. Natural Disaster or Circumstances Beyond Provider’s Control | When events such as hurricanes, wildfires, or declared public health emergencies prevent timely submission. | FEMA notice, MAC disaster bulletin, or public health emergency declaration. | MACs (e.g., First Coast, Noridian) issue local waiver notices during declared disasters. |
How to Request a Timely Filing Exception (Reopening Process)
If you believe an exception applies, you must request a claim reopening, not a standard appeal. Reopenings are handled directly by your MAC and typically use a bill type ending in “Q” (TOB xxQ).
Steps to Request a Reopening:
- Identify the denied claim (with CO 29 or N39011 denial).
- Gather documentation supporting the applicable exception category (CMS error, retro eligibility, etc.).
- Submit a TOB xxQ reopening claim via EDI or paper, as instructed by your MAC.
- Attach supporting evidence (screen captures, letters, or government bulletins).
- Monitor MAC correspondence — the reopening decision is separate from a redetermination.
Important : If no exception documentation is provided, the MAC will automatically uphold the denial as final.
Deadlines and Processing Time
- No explicit filing limit for reopenings if a valid CMS exception is proven.
- MACs typically process reopenings within 30–60 days.
- Resubmissions of “unprocessable” claims (RTPs) still must occur within the original 12-month limit, unless an exception applies.
- Each MAC publishes its own reopening request form or EDI instructions — these can be found on your MAC’s 2025 provider website
Staying Ahead of Medicare’s Timely Filing Rules in 2025
The 12-month Medicare timely filing rule continues to be one of the most critical compliance deadlines in medical billing. While the rule itself hasn’t changed for 2025, recent CMS updates—especially the removal of time limits for adjustments (CR 12909)—highlight Medicare’s effort to reduce administrative denials and simplify correction workflows. However, the burden remains on providers to:
- Track filing deadlines accurately,
- Resubmit unprocessable claims promptly, and
- Maintain documentation for any valid exception or reopening.
Missing even one filing window can lead to irrecoverable losses, particularly for high-volume facilities operating across multiple MAC jurisdictions.
At MedStates, we help healthcare providers stay compliant with:
- Automated RCM systems that track timely filing windows,
- Rejection management and reopening support for MAC exceptions, and
- Medicare billing expertise tailored to each jurisdiction’s rules.
If you’d like to protect your reimbursements and eliminate CO 29 denials, our billing team can implement full Medicare compliance monitoring for your practice.
👉 Contact MedStates today to streamline your Medicare claim submission and stay fully compliant with 2025 CMS rules
