Annual Debt Service (ADS)

Annual Debt Service (ADS) represents the total amount of principal and interest payments required on a property's mortgage obligations over one year. It is one of the most fundamental metrics in commercial real estate finance, serving as the basis for calculating debt service coverage ratios and determining a property's ability to support its financing.

ADS is calculated by multiplying the monthly mortgage payment (principal + interest) by 12. For properties with multiple loans-such as a senior mortgage plus mezzanine financing-ADS includes all debt obligations combined. Understanding ADS is critical for NNN investors because it directly determines the property's cash flow after debt service.

In the current lending environment, ADS calculations have become even more important as interest rates have risen from historic lows. A property that was comfortably cash-flow-positive at 3.5% interest rates may face negative leverage at 6.5%+ rates, meaning the debt service consumes a larger portion of NOI and reduces or eliminates cash distributions.

Lenders use ADS as the denominator in DSCR calculations to determine loan sizing. Most commercial lenders require a minimum DSCR of 1.20-1.25x, meaning the property's NOI must exceed ADS by at least 20-25%. For NNN properties, the predictable income stream from long-term leases typically supports favorable ADS-to-NOI relationships.

ADS is the single largest fixed expense for leveraged NNN investors and the primary determinant of cash-on-cash returns. When evaluating acquisitions, investors must stress-test ADS under different interest rate scenarios, especially for loans with upcoming rate resets or balloon payments. The spread between NOI and ADS determines distributable cash flow-a metric that drives investor returns. Rising interest rates have made ADS analysis critical, as many properties purchased at low rates face significantly higher debt service upon refinancing.

Annual Debt Service is calculated by multiplying the monthly mortgage payment (principal + interest) by 12. For a $5M loan at 6.5% with 25-year amortization, the monthly payment is approximately $33,800, making ADS about $405,600. If the property has multiple loans, add all monthly payments together before multiplying by 12.