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 provider file, your time-and-distance analysis, your adequacy attestations — 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. For a plan going live January 1 of a given year:

• Application availability announced: typically February of the prior year. This is when CMS releases the application materials, including the current-year network adequacy standards and provider file requirements.
• Application submission deadline: typically late May or early June. This is when your complete application — including the fully documented network adequacy submission — is due to CMS.
• CMS review and conditional approval: August through September. CMS reviews the application, may issue requests for information, and issues conditional approvals.
• Contract execution: October. CMS finalizes the contract with approved plans.
• Plan effective date: January 1. Members can begin enrolling in the Annual Enrollment Period (October 15 through December 7).

Work backward from the May submission deadline. That gives you roughly 12 to 16 weeks from "we are building a network" to "network adequacy documents are due to CMS." That timeline is not forgiving — and it assumes you started the network build, not that you started planning to start it.

What CMS requires at submission

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

• Provider file. Every in-network provider, including NPI, specialty taxonomy code, practice address, phone number, accepting-new-patients status, and contract effective date. This is a detailed data file, not a list of names.
• Time-and-distance analysis by county and specialty. CMS publishes the specialty types it evaluates and the applicable time-distance standards. Your analysis must demonstrate that members in each county in your service area have access to each required specialty within the applicable thresholds.
• 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 be documented with evidence of good-faith outreach efforts and a corrective action plan.
• State-specific requirements. Some states layer their own network requirements on top of CMS standards. If you're entering a state that has concurrent state DOI approval requirements for MA plans, those timelines may be even tighter.

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 calendar is announced. February announcement, May deadline — that's three months. You cannot build a compliant Medicare Advantage network from scratch in three months. The organizations that make the deadline started the network build the prior fall, before the application materials were even available, working from prior-year 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. CMS wants credentialed providers in your adequacy submission. Contracted-but-not-yet-credentialed providers don't count. Plans that don't account for this gap find themselves with a half-credentialed network at submission time.

Confusing letters of intent with signed contracts. LOIs are not contracts. A provider who has expressed interest in joining your network but hasn't signed a contract is not in your network. This sounds obvious, but in fast-moving builds with aggressive outreach teams, the distinction sometimes blurs in internal tracking. CMS doesn't accept LOIs as adequacy documentation.

Not running the time-and-distance analysis until the end. The adequacy analysis 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 September — eight months before the submission 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.