Getting an ARM looks almost identical to getting a fixed loan: same application, same documentation, same underwriting. The differences are in how you qualify and how the rate behaves later. On qualifying, the conventional (Fannie Mae) rules run like this. FHA and VA have their own versions, so don't treat these as universal: - For an ARM with an initial fixed period of 5 years or less, you qualify at the greater of the note rate plus the first rate-change cap, or the fully indexed rate (the index plus the loan's margin). Never the teaser rate alone. - For an initial fixed period longer than 5 years (a 7/6 or 10/6), you qualify at the note rate, unless the loan is higher-priced, in which case it's the greater of the note rate or the fully indexed rate. After the fixed period ends, the rate adjusts on a set schedule tied to its index, inside caps that limit each adjustment and the total lifetime move. A fixed loan never moves. Whether an ARM is worth it comes down to the discount. A hybrid ARM, fixed for 5, 7, or 10 years, earns its place when it prices meaningfully below the 30-year fixed, in the range of three-eighths to a half point better. That discount is what pays you for carrying the future adjustment risk. When the yield curve is inverted and short rates sit above long rates, the discount shrinks or disappears, and the ARM stops being worth it. Nobody can promise where the index heads, so weigh the guaranteed savings against the test that matters: could you live with the worst-case payment if things never improve?