Interest rates move every day, sometimes several times a day. For a buyer working through the home buying process, that movement can feel scary. What if rates jump between now and closing? What if you miss a better rate by waiting? These questions are exactly what a rate lock is designed to address. If you are buying a home, you may be wondering when and how your interest rate gets locked.

I'm John Shea, a mortgage advisor helping homebuyers and military families navigate the homebuying process throughout Maryland. The rate lock is one of the more important tools in the mortgage process, and understanding how it works helps you feel more confident about the timing of your purchase. Let me walk through the basics.

What a Rate Lock Actually Does

Here is the core idea. A rate lock helps protect you from market fluctuations for a set period of time while your loan is being processed. Understanding when you can lock your rate and how long it lasts can help you plan with confidence.

When you lock your rate, the lender commits to that specific interest rate for a defined period, regardless of what the market does. If rates go up after your lock, your rate stays the same. If rates go down, your locked rate does not automatically improve, though some lenders offer options for that situation.

The lock protects both you and the lender. You get certainty about your monthly payment and total cost. The lender knows exactly what terms they are committing to. Once the lock is in place, the interest rate portion of the equation is settled while you complete the rest of the loan process.

When You Can Lock Your Rate

You typically cannot lock your rate before you are under contract on a specific property. Some lenders offer programs that allow early rate locks in certain circumstances, but the standard timing is after you have an accepted offer.

This is one of the reasons pre-approval is so valuable. Being pre-approved means you can move quickly when you find the right home and go under contract. From there, we can lock the rate within a few days if the timing is right.

The specific moment to lock is a decision you make with your lender based on where rates are, how long you need the lock for, and your overall strategy. There is no single right answer that fits every situation.

How Long a Lock Lasts

Rate locks come with time limits. The most common lock periods are 30, 45, and 60 days, though longer locks are sometimes available for special situations like new construction.

The lock period needs to cover the time from when you lock to when you actually close. If your closing is scheduled for 40 days from now, a 30 day lock would not be enough. You would need at least a 45 day lock to cover the full period.

Longer locks typically cost more, either as a slightly higher rate or as a lock fee. This is because the lender is taking on more risk when they commit to a rate for a longer period. For most standard purchases, a 30 or 45 day lock covers the closing timeline without extra cost.

What Happens If You Need More Time

If your closing gets pushed back for some reason and your lock is about to expire, you have options. Most lenders offer lock extensions, though there is usually a fee. The exact cost depends on how many extra days you need and current market conditions.

Sometimes closings get delayed by things outside your control, like appraisal issues, seller delays, or paperwork complications. Working with a lender who anticipates these situations and helps you plan for them makes the whole process smoother.

For military buyers on a PCS timeline, timing pressure is often especially high. Coordinating your close with orders, travel, and family logistics can be complicated. This is one of the reasons working with a lender who specializes in military transactions matters, as they know how to navigate the timing challenges that come with military moves. You can read more about how the VA program supports these situations on John's VA loan options page.

The Timing Question

The question of when to lock is where a lot of buyers get anxious. Should you lock right away when you go under contract? Wait a few days to see if rates improve? Try to time the market?

The honest answer is that trying to time the market rarely works. Rates move based on many factors, and even mortgage professionals cannot reliably predict where they will go next. What matters more is that you lock at a rate that supports your comfortable monthly payment and gives you the confidence to move forward.

If your monthly payment works at the current rate, locking sooner rather than later removes uncertainty. If rates are trending in your favor and you have time, waiting a few days might make sense. But the calculation is usually more about protecting yourself from downside risk than trying to catch the perfect low.

If you want to think through how your monthly payment should look at different rates, John's post on structuring your VA home loan for the right monthly payment walks through how to set a payment that fits your goals.

What If Rates Drop After You Lock

If rates drop significantly after you lock, you may wonder whether you missed out. In most cases, once your rate is locked, that is your rate. However, some lenders offer float down options that let you take advantage of a rate drop under specific conditions.

Float down options usually come with terms. There may be a fee, a minimum amount rates need to drop, and specific timing rules. Not every lender offers this, and not every situation qualifies.

Even without a float down, remember that you can always refinance later if rates drop meaningfully. If you buy now at a locked rate and rates fall significantly in the next year or two, refinancing to a lower rate becomes a real option. Your rate today is not necessarily your rate forever.

Different Loan Programs and Rate Locks

Rate lock mechanics work similarly across most loan programs. Conventional, FHA, VA, and USDA loans all use rate locks with generally similar timing and terms. The specific rates available vary between programs, but the process of locking is consistent.

For eligible military buyers, VA loans often offer competitive rates that make the locking decision easier. Combined with no monthly mortgage insurance and no down payment requirement, the VA program often produces strong outcomes even in changing rate environments.

Common Mistakes to Avoid

A few patterns hurt buyers when it comes to rate locks. The first is waiting too long, hoping for a better rate that may or may not come. Every day you wait to lock is another day rates could move against you.

The second is picking a lock period that does not cover your actual closing timeline. If your lock expires before closing, you either pay for an extension or risk being repriced at whatever the market rate is at that time.

The third is not understanding what a lock commits you to. A locked rate is generally binding on both sides, meaning you cannot easily walk away and shop for a better rate elsewhere without consequences.

A Few Practical Tips

A handful of things help buyers use rate locks well. First, talk to your lender about timing early in the process. Knowing what your options are before you go under contract helps you make faster decisions when the time comes.

Second, choose a lock period that provides some buffer. If your expected closing is in 30 days, a 45 day lock gives you room for the small delays that often happen.

Third, focus on the payment, not just the rate. A slightly higher rate that produces a payment you are comfortable with is better than chasing a lower rate that keeps slipping away.

Fourth, work with a lender who watches the market for you. You should not have to track rates yourself. A good lender will let you know when locking makes sense based on where rates are and where they seem to be heading.

A Few Final Thoughts

Rate locks are one of the tools that make the mortgage process more predictable. They give you certainty about a piece of the equation while you handle everything else. Used well, they take one worry off your plate.

The buyers who feel most confident during the closing process are usually the ones who understand how their rate lock works, when it expires, and what to do if timing gets tight. That understanding comes from a real conversation with a lender who takes the time to explain the options for your specific situation.

Let's Talk About Timing

If you are preparing to buy and have questions about interest rates or the timing of the process, my team and I are here to help. Reach out and we will walk through your situation, help you understand your rate lock options, and put together a plan that gives you confidence throughout your Maryland home purchase.