Customer acquisition cost

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

Define the acquisition event first

The basic formula is:

CAC = acquisition costs assigned to a cohort / unique new clients reaching the defined event

An inquiry, qualified referral, conditional acceptance, assessment start, first service, and collected first payment are different events. A practice might call first service its acquisition event because it represents actual care delivery. Another may track assessment-start CAC separately because the assessment has its own staffing and payer gates. Name the event beside every result.

Define the client unit too. Use unique people, rather than phone calls, forms, appointments, claims, or family contacts. Decide how transfers, returning clients, siblings, duplicate referrals, and multiple funding routes enter the count.

The SBA market-research guidance recommends examining demand, market size, location, saturation, and pricing. That context can shape a growth plan. It supplies no ABA CAC benchmark, so a practice should build its own comparable cohorts.

Lock the costs and cohort window

A direct-media CAC may include only ad and agency spend. A fully loaded CAC may also include creative work, landing pages, call tracking, CRM tools, events, allocated marketing staff time, and approved referral-development costs. Both can be useful when clearly labeled. Keep the allocation method consistent and include failed campaigns.

Match costs to the clients they could influence. If a campaign runs in January while referrals take 90 days to reach first service, a January spend divided by January starts mixes different cohorts. Give every included referral the same maturity window, freeze the cutoff, and retain open, withdrawn, held, and referred-elsewhere outcomes in the cohort record.

Attribution also needs a rule. A family may encounter a search ad, pediatrician, directory, webinar, and friend. Choose first touch, last meaningful touch, a documented multi-touch method, or an unattributed category. Report the method with the number. Avoid changing attribution simply to improve a channel's result.

A fictional ABA practice calculation

A fictional practice locks $30,000 of fully loaded acquisition cost to 40 attributed referrals. Every referral has a complete 90-day observation window. By the cutoff, 24 people have started an assessment and 18 have reached first service.

• Assessment-start CAC is $30,000 / 24 = $1,250.
• First-service CAC is $30,000 / 18 = $1,666.67.
• The practice reports the remaining 22 first-service outcomes by reason and age at closure.

Channel A accounts for $12,000 and 10 first-service starts, producing a CAC of $1,200. Channel B accounts for $18,000 and eight starts, producing $2,250. The combined CAC remains $30,000 / 18 = $1,666.67. Averaging the two channel CAC figures would produce $1,725 and give unequal channels equal weight.

These calculations describe acquisition under the stated rules. They do not show which channel produced better clinical fit, family experience, retention, access, or contribution margin.

Pair CAC with capacity and unit economics

A low CAC can still create poor results when a practice lacks qualified staff, supervision, assessment capacity, payer readiness, or accessible communication. Segment results by service, location, payer path, channel, and cohort only when each segment remains large enough to interpret responsibly.

Compare CAC with expected contribution margin and cash timing using supportable assumptions. Revenue is different from contribution margin. Authorization limits, cancellations, payroll, supervision, denials, refunds, recoupments, and collection lag affect the amount and timing of cash. A short retention period can make an attractive acquisition price uneconomic.

Useful companion measures include response time, qualified-referral rate, assessment-start rate, first-service rate, days between stages, capacity holds, family-reported clarity, retention by a predeclared window, and contribution margin by mature client cohort. Preserve raw counts with every percentage.

Marketing controls belong inside the calculation

The FTC Advertising FAQs explain that objective claims need a reasonable basis before dissemination. The FTC's Health Products Compliance Guidance says health-related benefit and safety claims require appropriate support and that a testimonial cannot carry a claim the advertiser could not substantiate directly.

The FTC's Consumer Reviews and Testimonials Rule Q&A addresses fake or false reviews, sentiment-conditioned incentives, insider relationships, and controlled review sites presented as independent. Record review and testimonial controls as campaign costs instead of treating compliance as free.

For a HIPAA covered entity, HHS marketing guidance says marketing uses and disclosures of protected health information generally require authorization, subject to defined exceptions. Confirm the exact activity, data, entity role, authorization, vendor relationship, and other applicable privacy law before sharing client information or building an audience.

OIG's fraud and abuse overview explains that the federal Anti-Kickback Statute prohibits knowing and willful remuneration to induce or reward referrals or business involving federally payable items or services. State law and payer contracts may add other restrictions. Route referral fees, gifts, discounts, lead payments, and beneficiary incentives to qualified compliance and legal review before launch.