The CMS application calendar every new MA entrant needs to know.

First-year Medicare Advantage applications are the most compressed network builds in this business. CMS publishes the application calendar annually, and the dates don't move. Network adequacy documentation (your HSD tables and any exception requests) is due with the application. Most new entrants don't understand how little time that leaves for the actual network build.

The conversation we have most often with organizations considering an MA entry goes something like this: they have identified a service area, they have financial projections, they have a market rationale. What they do not have is a realistic picture of the build timeline. The application deadline feels abstract until it is three months away and you have a partially contracted network and a credentialing queue that hasn't cleared committee.

The calendar is public. The discipline is knowing what it means for network operations — and starting early enough to meet it.

The application calendar

CMS publishes the application cycle timing each year, and while specific dates shift slightly, the structure is consistent. Here is the cycle for a plan going live January 1, with the dates CMS set for contract year 2027 as the example:

• Applications posted: early January of the prior year (January 7, 2026 for CY2027). This is when CMS releases the application materials and instructions.
• Notice of Intent to Apply: due in January (January 23, 2026 for CY2027).
• Application deadline: mid-February (February 11, 2026 for CY2027). Since contract year 2024, a new or expanding plan has to demonstrate network adequacy as part of the application itself, through Health Service Delivery (HSD) tables listing providers and facilities with executed contracts or, during the application review only, a letter of intent signed by both parties. CMS can deny an application on network adequacy alone.
• Bids: due the first Monday in June.
• Review and contracting: spring through late summer. CMS reviews the application, runs HSD review rounds where you can correct deficiencies and request exceptions, and finalizes contracts with approved plans ahead of open enrollment.
• Plan effective date: January 1. Members can begin enrolling in the Annual Enrollment Period (October 15 through December 7).

Work backward from the February deadline. The application materials are posted only about five weeks before they are due. Every provider on the HSD tables needs either an executed contract or a letter of intent signed by both parties, and every LOI has to become an executed contract by January 1. In practice, the network has to be largely negotiated before the application even opens.

Sources: CMS CY2027 Part C application; 42 CFR 422.116 (network adequacy); CMS network adequacy guidance (December 2024). Check the current year's HPMS memos for exact dates.

What CMS requires at submission

The network adequacy submission is not a high-level summary. CMS wants specific, provider-level documentation:

• Provider and facility HSD tables. Every contracted provider and facility, with NPI, the CMS HSD specialty code and the address where they see patients. Providers covered by a letter of intent are flagged in the LOI column. This is a detailed data file, not a list of names.
• Time-and-distance results by county and specialty. You don't submit your own analysis. CMS runs the time-and-distance test itself against your HSD tables and returns pass or fail results by county and specialty in an Automated Criteria Check (ACC) report. Every county in your service area has to pass for every required specialty, or be covered by an approved exception.
• Adequacy attestation. A signed statement from an authorized organizational representative attesting that the network meets applicable standards. This is a legal attestation with compliance consequences — not administrative paperwork.
• Exception documentation for counties that don't meet standards. Rural markets and specialty shortage areas often require exceptions. Those exceptions must show that the providers CMS lists aren't actually available (retired, not contracting with any plan, exclusive to a competitor) and that your network matches the Original Medicare pattern of care. CMS will generally not accept “we couldn't reach terms” as the reason.
• Where state rules fit. For Medicare Advantage, CMS standards govern network adequacy and override state rules. The state still licenses the plan, and its own standards apply to your Medicaid and commercial products.

Where plans run into trouble

The failure modes are consistent enough that we can describe them with confidence. Plans that miss CMS submission deadlines or receive extensive RFIs almost always fall into one of these patterns:

Starting the build after the application is posted. Posted in early January, due in mid-February: that's about five weeks. You cannot build a compliant Medicare Advantage network in five weeks. The organizations that make the deadline started the network build the prior spring or summer, working from the prior year's standards and their own market research.

Underestimating credentialing lead time. You can get a provider to sign a contract in two weeks if the negotiation goes well. Getting that provider through credentialing takes another four to eight weeks — primary source verification, CAQH review, committee approval. Contracted providers can go on the tables, but a provider who isn't credentialed by January 1 can't see your members. Plans that don't account for this gap pass the application review and then open in January with a network that exists on paper but isn't ready to see patients.

Confusing letters of intent with signed contracts. Since contract year 2024, CMS lets new and expanding applicants count a provider covered by a letter of intent signed by both parties, flagged on the HSD tables, while the application is under review. That is a bridge, not a contract. Every LOI has to become an executed contract by January 1, and applicants that use LOIs get a full network review in their first operating year. A provider who has only said they're interested is covered by neither. In fast-moving builds with aggressive outreach teams, that distinction sometimes blurs in internal tracking.

Not running the time-and-distance analysis until the end. CMS runs the official test, but your own replica of it should run continuously throughout the build — monthly at minimum, weekly in the final weeks before submission. Running it once at the end and discovering you have specialty gaps in three counties is a problem you can't solve in the time remaining. Running it monthly means you catch gaps while you still have time to fill them.

The CMS deadline doesn't move. The network build has to start early enough to finish in time — not the other way around.

If you are planning a first-year MA application, the network build should begin no later than the prior June, about eight months before the February deadline. That gives you time to run outreach, negotiate contracts, complete credentialing, validate provider data, run adequacy analysis, identify gaps, address exceptions, and submit clean documentation. Anything less than that and you are building against the clock — which is a recoverable situation, but one that costs significantly more in staff time, expedited contracting, and risk of RFIs than starting eight months out would have.

Sources: 42 CFR 422.116 (letters of intent at (d)(7); exceptions at (f)); CMS network adequacy guidance, December 2024 (sections 3.1, 4.1, 4.2, 5.6, 5.7); 42 CFR 422.402 (federal preemption of state law).