# LongevityEHR blog

Source: https://www.longevityehr.com/blog

- [Intrinsic Capacity: What It Is and How Clinics Measure It](https://www.longevityehr.com/blog/intrinsic-capacity): Intrinsic capacity explained: the five domains, how clinicians measure it, what the evidence says, and how a longevity clinic can track it over time.
- [How to Manage Subscription Billing in a Cash-Pay Clinic](https://www.longevityehr.com/blog/manage-subscription-billing): How longevity and cash-pay clinics can run membership billing: renewals, failed payments, HIPAA-safe card handling and cancellation rules that apply.