How to save money on network adequacy and access reporting

For managed care organizations (MCOs) serving Medicaid and Medicare members, network adequacy reporting is both essential and potentially costly. States vary widely in their requirements, but most go beyond provider-to-member ratios. Many mandate that in-network providers be located within a specific driving time or driving distance of members.

That’s where things can get expensive.

Imagine a network with 10,000 providers serving 100,000 insured members. That’s 1 billion possible provider–member combinations. Using standard distance-matrix APIs like Google Maps, those calls can easily run into a six-figure expense.

Below are four strategies to reduce costs without completely sacrificing accuracy.

1. Use Census Geocoder to get coordinates

Start with the Census Bureau’s Geocoder. It’s free and converts addresses into latitude/longitude coordinates. While it won’t calculate travel times or road miles, it’s the best no-cost starting point for generating geographic coordinates.

2. Round coordinates to the third decimal place

By default, the Census Geocoder returns coordinates out to 12 decimal places — accuracy down to 100 nanometers. That’s far more precision than is useful for network adequacy.

Rounding to three decimal places balances accuracy and efficiency. This gets you to within 100 meters, or about the size of a large parking lot. Providers in medical complexes or dense metro areas often cluster within this margin anyway. Reducing duplicate or near-duplicate coordinates can shrink your dataset by as much as one-third.

3. Replace member addresses with county “Centers of Population”

Instead of calculating distances from each member’s unique address, leverage the Census Bureau’s Centers of Population. These represent the weighted geographic center of each county’s population.

For example, Maryland has 23 counties plus Baltimore City. Using county centers reduces 100,000 member points to just 24.

County	Latitude	Longitude
Allegany	39.628458	-78.820665
Anne Arundel	39.071038	-76.604417
Baltimore	39.368834	-76.620325
Calvert	38.551108	-76.544070
…

In our 10,000-provider/100,000-member example, combining this step with rounding shrinks the workload from 1 billion combinations to about 158,400 — a massive cost savings with acceptable loss of granularity.

4. Skip APIs and calculate “as-the-crow-flies” miles with a formula

For even bigger savings, skip paid APIs entirely. Once you have coordinates, you can calculate straight-line distances with the Haversine formula. Or a more compact alternative, the Spherical Law of Cosines formula, shown below.

SELECT
    provider_id
    , provider_latitude
    , provider_longitude
    , member_id
    , member_latitude
    , member_longitude
    , (3959 *
        ACOS(
            COS(RADIANS(member_latitude)) 
            * COS(RADIANS(provider_latitude))
            * COS(RADIANS(provider_longitude) - RADIANS(member_longitude)) 
            + SIN(RADIANS(member_latitude)) 
            * SIN(RADIANS(provider_latitude))
        )
    ) AS map_miles
FROM yourtable

-- Alternative way to calculate distance in modern versions of SQL Server.
SELECT
    provider_id
    , provider_latitude
    , provider_longitude
    , member_id
    , member_latitude
    , member_longitude
    (
        GEOGRAPHY::Point(member_latitude, member_longitude, 4326)
        .STDistance(GEOGRAPHY::Point(provider_latitude, provider_longitude, 4326))
    ) / 1609.344 AS map_miles
FROM yourtable

Since real-world roads aren’t straight lines, apply a detour index: about 1.4 for rural areas and 1.2 for urban areas. To approximate drive times, divide by an average commuting speed of 32 mph.

This approach won’t satisfy every regulatory requirement, but it can provide a defensible, low-cost estimate of accessibility.

Conclusion

Network adequacy reporting doesn’t have to break your budget.

• Start with free Census data for geocoding.
• Reduce redundancy by rounding coordinates.
• Use county-level centers of population to represent members.
• Or skip APIs entirely and calculate distances with a detour adjustment.

Each method trades some precision for cost savings. The right choice depends on your compliance environment and how much accuracy regulators require — but even modest adjustments can reduce API costs by 90 percent or more.

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Contact Charadata for help with network adequacy and access reporting.