Serviceable obtainable market

Editorial approval scope: The team checked current source fidelity, scope boundaries, dates, arithmetic, reader usefulness, practical workflow, and general-information limitations.

SOM is the constrained opportunity

TAM estimates the broad total opportunity. SAM filters TAM to the segment the service model could address. SOM adds the practice's likely capture and delivery constraints for a defined horizon.

The relationship is usually:

SOM ≤ SAM ≤ TAM

Use the same unit throughout. If SAM is annual service starts, SOM should be annual service starts. Convert to hours or revenue in a separate, fully stated calculation.

Start with the smaller of demand and capacity

A simple planning boundary is:

obtainable volume = minimum of supported demand and release-ready capacity

Supported demand comes from a mature referral or market model. Release-ready capacity comes from qualified people, supervision, schedule, setting, payer and financial routes, access supports, and operating controls that can actually deliver the service.

Marketing share alone is weak. A practice cannot obtain 20% of SAM when it has rooms, staff, or authorization pathways for 5%.

Build capacity from real resources

Model each worker once. Reserve supervision, training, documentation, meetings, travel, breaks, leave, cancellations, and other duties before assigning service hours. Match credentials, licensure, payer recognition, setting, location, and schedule to the work.

Federal DOL Fact Sheet #22 says job-site-to-job-site travel during the workday is work time under the FLSA, while ordinary home-to-work travel generally is not. Other law and actual facts can change the result. Wage-hour treatment and payer reimbursement are separate questions.

Supervision can be the binding constraint even when technician hours appear available. Use calendars, ratio or volume standards, case complexity, and safe backup coverage rather than a single headcount multiplier.

Add nonstaff release gates

Capacity should clear:

• entity, professional, facility, setting, and modality authority
• payer participation or another documented financial path
• case-specific authorization when required
• accessible site, communication, and technology supports
• rooms, equipment, travel zones, and safe schedules
• referral and intake throughput
• payroll, lease, vendor, and working-capital requirements
• implementation time for hiring, credentialing, training, and opening

One blocked gate can reduce the obtainable market below apparent demand and staffing.

A fictional SOM calculation

Cedar Path ABA, a fictional practice, has a SAM of 180 annual service-start opportunities. Its demand model supports 60 likely accepted offers during the next 12 months.

The staffing calendar supplies 7,200 direct-service hours after reserving all other duties. The chosen service model needs an average 480 direct hours per full-year client equivalent. Hour capacity is floor(7,200 / 480) = 15.

Supervision capacity supports 13 equivalents. Facility and schedule capacity support 14. Payer-ready configuration and working capital support 12. The binding capacity is 12. SOM is the smaller of 60 supported demand and 12 release-ready capacity, so the base SOM is 12 full-year client equivalents.

This figure is not twelve guaranteed clients or admissions. Starts occur at different dates, service hours vary, and authorizations, staffing, family choice, cancellations, and clinical fit can change.

Use scenarios instead of one heroic number

Build base, downside, and severe cases. Vary qualified hiring dates, vacancy, turnover, authorization delay, cancellations, service mix, supervision, facility opening, travel, reimbursement timing, and conversion.

Report the binding constraint in every scenario. If downside SOM falls from 12 to 8 because supervision is limited, more advertising will not repair the gap. The decision may be supervisor recruitment, narrower geography, a later launch, or a smaller lease.

Keep demand and share honest

The SBA market-research guide recommends examining demand, market size, location, saturation, and pricing. Combine public context with community input and mature first-party cohorts.

Avoid assuming every diagnosed person wants the service, every referral qualifies, every payer covers it, or every competitor's client is available. Family choice, alternative services, provider fit, access, and clinical recommendations remain real.

Validate SOM monthly

Compare modeled and actual inquiries, reviews, offers, accepted starts, qualified hires, credentialing dates, service hours, supervision use, cancellations, authorizations, cash, and access actions. Explain variance by driver.

Keep original scenarios intact and start a new version when assumptions change. A repeatedly missed SOM is evidence that the model or execution needs revision, not a reason to relabel the shortfall.

Assign one owner to reconcile the model with staffing, payer, facility, and cash records each month. Track forecast error by driver, approve assumption changes, and preserve the prior version for comparison.

Record corrective actions when actual capacity misses the approved scenario.